I made a post in which I estimated the total energy use in my family. It was disturbing, in that we use a LOT of energy and there aren't a lot of places where cuts are easy (hypermiling my 3 ton SUV notwithstanding). Over 18 months have gone by since I wrote that article, and I've learned a few things. None would change the overall thrust of the article though; the main modification would be in the energy content of purchased items (the so-called "embedded energy"). I estimated one third of the cost of the average purchased item went for the total energy used in producing it, I now think that's probably too high.
But the last couple of weeks have been quite hot (around 100 degrees F for a daytime peak) and I've had the air conditioner on quite a bit. Our air conditioning system was manufactured in 1995 by Goodman Manufacturing and is a model CK60-18. As best I can tell, this means it's rated at a little under 60,000 BTU/hour (about 56,000) cooling capability at a Seasonal Energy Efficiency Ratio ("SEER") of about 10.5. This is typically found by adjusting the Energy Efficiency Ratio ("EER") which is defined as the cooling capacity over a period (e.g., BTU/hour) divided by the power used during that period in kilowatts at a particular outdoor temperature. Thus, EER is a mixed unit, BTU/hour/kilowatt. In dimensional terms, it's unitless but it's expressing how much energy it takes to move any particular amount of heat from inside to outside in a particular amount of time. Residential central air conditioners installed in the United States after 2006 are required to have a SEER of at least 13.
Air conditioner cooling capacity can also be rated in "tons," equivalent to the ability to move 12,000 BTU/hour from inside to outside in an hour. This unit hearkens back to the days when ice was used for cooling and the melting of a (short) ton of ice removes about 288,000 BTU from the environment, so doing so in a day uses 12,000 BTU per hour. My air conditioner thus provides the equivalent cooling capacity of about 5 tons of melting ice and hence is a five ton unit. Furlongs per fortnight anyone?
Now interestingly, working it out, my air conditioner will move 56,000 BTU of thermal energy from the inside my house to the outdoors in an hour. 56,000 BTU/hour is energy divided by time or power and is equivalent to about 16,400 watts. But the EER is about 9.5 so, since EER=(btu/hour)/watts, the electrical energy input is (BTU/hour)/EER or 5,890 watts. That's nice, my air conditioner produces about 2.8 times as much heat output as electrical energy input. Has Goodman Manufacturing succeeded in defying the law of conservation of energy and the first and second laws of thermodynamics? And by specifying a SEER no less than 13 is the U.S. government requiring changing the laws of physics?
No. The electrical input is used to compress a fluid and pump it around a circuit (absorbing heat from room air by changing from a liquid to a gas in the evaporator coil, then releasing it by changing back to a liquid) and to power a fan to blow the air cooled by the coil into the rooms of the house. Thus, the work being done is the movement and compression of fluids. The entropy of the air inside the house is decreased, that of the air outside is increased more in strict accordance to the second law.
The functioning of an air conditioning system is the same as that of a refrigerator and the most wonderful television series of all time, "The Secret Life of Machines," covers the refrigerator (among many other fascinating topics), here. A series of three YouTube videos comprising that episode are embedded below, but all episodes can be downloaded in their entirety. I heartily recommend doing so.
If my air conditioner is operating at a SEER of 9 (it's 14 years old after all), and I replace it with a new one with an SEER of 14, what can be saved? Well, I'll use 9/14 as much electrical energy, and I estimate that I'm using 560 hours per air conditioning season at about 5 kilowatts costing about $0.125/kilowatt hour. This will cost me about $350. If I buy the new unit, I'll spend (9/14)*$350 or $225, saving $125. It will take a very, very long time to pay for the new unit at that rate.
Monday, September 07, 2009
Sunday, August 30, 2009
A quick follow-up
My previous post dealt with the total energy required in using various means to go to the store for groceries. My conclusion was counter-intuitive, in that it appears that bicycling uses more energy than an electric scooter. Now clearly if I'm fulfilling another purpose, e.g., maintaining a level of physical activity for fitness, the energy issue may not be the deciding factor in my choice. And bicycles are cheaper than viable electric scooters.
But, speaking of price, let's focus on the cost analysis from an energy point of view. The energy used in my means of transportation should be reflected in the price I pay to use it so I'll see what each method costs. From the previous post, if I walk I'll have to buy 491 kilocalories of food to make the trip. Clearly, all kilocalories are not created equal, but I estimate that if I eat 2500 kilocalories/day and am doing so in a "not too unhealthy" way, I might spend about $7.00, or $0.0028/kilocalorie. Thus, my trip costs .0028*491=$1.37. An identical calculation for the bicycle, using the 162 kilocalories from my earlier post, results in a cost of $0.45.
For the electric scooter, I'll use 751,000 joules or 0.208 kilowatt hours (the 638,000 joules used by the trip divided by the 85% charger efficiency, i.e., this is what I pay for). This will cost me a little less than $0.03. Pretty darn cheap!
For the smart fortwo, I'll use $0.59 worth of gasoline (6 miles at 33 m.p.g. and premium fuel at $3.239/gallon) and for the Land Rover LR3 HSE, it will be $1.10.
So the cost results, surprisingly, do change the order. It's cheaper, in end user energy purchase price, to drive than to walk. This holds true even in my three ton Land Rover. Shocking indeed, but I don't see a huge error. Obviously, electricity and gasoline are commodities and food isn't so I can, to a certain extent, choose what to pay for a kilocalorie. One thing that quickly jumps out is that food is expensive! I bet no one reading was aware of this obscure fact.
Perhaps if I choose food for minimum kilocalories/dollar, I could cut the price by something like 70%. Doing that makes the trip $0.13 on the bicycle and $0.39 to walk. I think this is at least a reasonable view, the cost per kilocalorie above the minimum is for taste, convenience, "earth friendliness," etc. and not for energy. This adjustment changes the order back to a match for the total energy conversion analysis.
To recap (using minimal food cost):
Electric Scooter: $0.03
Bicycle: $0.13
Walking: $0.39
smart fortwo: $0.59
Land Rover LR3 HSE: $1.10
To recap (using food I typically buy):
Electric Scooter: $0.03
Bicycle: $0.45
smart fortwo: $0.59
Land Rover LR3 HSE: $1.10
Walking: $1.37
But, speaking of price, let's focus on the cost analysis from an energy point of view. The energy used in my means of transportation should be reflected in the price I pay to use it so I'll see what each method costs. From the previous post, if I walk I'll have to buy 491 kilocalories of food to make the trip. Clearly, all kilocalories are not created equal, but I estimate that if I eat 2500 kilocalories/day and am doing so in a "not too unhealthy" way, I might spend about $7.00, or $0.0028/kilocalorie. Thus, my trip costs .0028*491=$1.37. An identical calculation for the bicycle, using the 162 kilocalories from my earlier post, results in a cost of $0.45.
For the electric scooter, I'll use 751,000 joules or 0.208 kilowatt hours (the 638,000 joules used by the trip divided by the 85% charger efficiency, i.e., this is what I pay for). This will cost me a little less than $0.03. Pretty darn cheap!
For the smart fortwo, I'll use $0.59 worth of gasoline (6 miles at 33 m.p.g. and premium fuel at $3.239/gallon) and for the Land Rover LR3 HSE, it will be $1.10.
So the cost results, surprisingly, do change the order. It's cheaper, in end user energy purchase price, to drive than to walk. This holds true even in my three ton Land Rover. Shocking indeed, but I don't see a huge error. Obviously, electricity and gasoline are commodities and food isn't so I can, to a certain extent, choose what to pay for a kilocalorie. One thing that quickly jumps out is that food is expensive! I bet no one reading was aware of this obscure fact.
Perhaps if I choose food for minimum kilocalories/dollar, I could cut the price by something like 70%. Doing that makes the trip $0.13 on the bicycle and $0.39 to walk. I think this is at least a reasonable view, the cost per kilocalorie above the minimum is for taste, convenience, "earth friendliness," etc. and not for energy. This adjustment changes the order back to a match for the total energy conversion analysis.
To recap (using minimal food cost):
Electric Scooter: $0.03
Bicycle: $0.13
Walking: $0.39
smart fortwo: $0.59
Land Rover LR3 HSE: $1.10
To recap (using food I typically buy):
Electric Scooter: $0.03
Bicycle: $0.45
smart fortwo: $0.59
Land Rover LR3 HSE: $1.10
Walking: $1.37
Saturday, August 29, 2009
Going to the store
Hypothetical question (its hypothetical nature will be explained later): A grocery store is located 3 miles from my door with a level path. I need groceries that will fit in a single bag. How much fossil fuel is used, ALL INPUTS CONSIDERED, if I: walk; ride a bicycle; take an electric scooter; drive a smart fortwo; drive my LR3 HSE. I'll assume the two gasoline vehicles are warmed up.
As is typical, I'll be making estimates, but I doubt that the order will be wrong. Let's start with walking. Assuming I walk at 3 m.p.h., it will take 120 minutes to walk to the store and back. Using this calculator, I find that I'll convert 491 kilocalories of food energy to heat (the site calls them calories but this is incorrect). Now, it is said that 7 to 10 kilocalories of fossil fuel energy are required to produce a kilocalorie of food. I'll use 8.5, so 8.5*491=4170 kilocalories or 17.5*10^6 joules of fossil fuel energy to get me to the store and back.
How about a bicycle? Using the very nice calculator here and assuming I ride at 10 m.p.h. (faster on the way there, slower on the way back), I find I'll burn 162 kilocalories of food energy requiring 8.5*162=1377 kilocalories or 5.76*10^6 joules of fossil fuel energy.
Looking at the electric scooter, I'll use the Zapino (previously posted about here) as my representative. The optional 60 volt, 40 amp-hour Lithium battery supposedly gives it a range of "about 65 miles." Now, 60 volts at 40 amps for an hour is 8.64*10^6 joules but I would think the range would be based on, say, 80% discharge. So that means it uses 8.64*10^6*0.8/65=106,000 joules/mile and my 6 mile trip would use 638,000 joules. But wait. The charger would only be about 85% efficient and transmission of electricity is typically about 60% efficient. So I'll use 638,000/(0.85*0.6)=1.25*10^6 joules of electricity from the generating station. Are we done? No, this electricity is likely generated by a fossil fuel plant whose efficiency is on the order of 50%, so double that to 2.50*10^6 joules of primary fossil fuel energy. Finally, using an EROEI (energy return on energy invested) of 7.5:1, we multiply 2.50*10^6*8.5/7.5 to find that it requires 2.83*10^6 joules of primary fossil fuel energy in total to go to the store and back.
The smart fortwo about which I posted here? Certainly this will be city driving where the fortwo is listed by the EPA at 33 m.p.g. A nice little article singing the Tesla's praises gives me the "well to wheel" data I need. Without bothering my patient readers with the conversions and calculations, I find that the fortwo uses 28.9*10^6 joules of primary energy (including well to pump to wheel efficiency) to accomplish the mission. It should be noted that a "hypermiler" could likely do significantly better.
Finally, the LR3 HSE (with me driving it) will achieve about 17.6 m.p.g. in the city and thus uses 54.2*10^6 joules of primary energy to go to the store. So the electric scooter is the best, using about 5% of the energy of the LR3. Surprisingly, the bicycle uses twice as much energy (remember, all fuel inputs to food production are included and no distinction is made for vegetarian versus omnivorous diet, so your mileage may vary) as the scooter and walking even more. I may have to revisit the scooter yet again. And why is the question hypothetical? It's down a long and steep hill from my house to the store and, more importantly, up that long and steep hill to get back.
To recap:
Electric Scooter: 2.83*10^6 joules
Bicycle: 5.76*10^6 joules
Walking: 17.5*10^6 joules
smart fortwo: 28.9*10^6 joules
Land Rover LR3 HSE: 54.2*10^6 joules
Update: A very interesting analysis of the bicycle versus electric bicycle (scooter) energy requirements that includes life-cycle energy consideration done as a term paper is available here.
As is typical, I'll be making estimates, but I doubt that the order will be wrong. Let's start with walking. Assuming I walk at 3 m.p.h., it will take 120 minutes to walk to the store and back. Using this calculator, I find that I'll convert 491 kilocalories of food energy to heat (the site calls them calories but this is incorrect). Now, it is said that 7 to 10 kilocalories of fossil fuel energy are required to produce a kilocalorie of food. I'll use 8.5, so 8.5*491=4170 kilocalories or 17.5*10^6 joules of fossil fuel energy to get me to the store and back.
How about a bicycle? Using the very nice calculator here and assuming I ride at 10 m.p.h. (faster on the way there, slower on the way back), I find I'll burn 162 kilocalories of food energy requiring 8.5*162=1377 kilocalories or 5.76*10^6 joules of fossil fuel energy.
Looking at the electric scooter, I'll use the Zapino (previously posted about here) as my representative. The optional 60 volt, 40 amp-hour Lithium battery supposedly gives it a range of "about 65 miles." Now, 60 volts at 40 amps for an hour is 8.64*10^6 joules but I would think the range would be based on, say, 80% discharge. So that means it uses 8.64*10^6*0.8/65=106,000 joules/mile and my 6 mile trip would use 638,000 joules. But wait. The charger would only be about 85% efficient and transmission of electricity is typically about 60% efficient. So I'll use 638,000/(0.85*0.6)=1.25*10^6 joules of electricity from the generating station. Are we done? No, this electricity is likely generated by a fossil fuel plant whose efficiency is on the order of 50%, so double that to 2.50*10^6 joules of primary fossil fuel energy. Finally, using an EROEI (energy return on energy invested) of 7.5:1, we multiply 2.50*10^6*8.5/7.5 to find that it requires 2.83*10^6 joules of primary fossil fuel energy in total to go to the store and back.
The smart fortwo about which I posted here? Certainly this will be city driving where the fortwo is listed by the EPA at 33 m.p.g. A nice little article singing the Tesla's praises gives me the "well to wheel" data I need. Without bothering my patient readers with the conversions and calculations, I find that the fortwo uses 28.9*10^6 joules of primary energy (including well to pump to wheel efficiency) to accomplish the mission. It should be noted that a "hypermiler" could likely do significantly better.
Finally, the LR3 HSE (with me driving it) will achieve about 17.6 m.p.g. in the city and thus uses 54.2*10^6 joules of primary energy to go to the store. So the electric scooter is the best, using about 5% of the energy of the LR3. Surprisingly, the bicycle uses twice as much energy (remember, all fuel inputs to food production are included and no distinction is made for vegetarian versus omnivorous diet, so your mileage may vary) as the scooter and walking even more. I may have to revisit the scooter yet again. And why is the question hypothetical? It's down a long and steep hill from my house to the store and, more importantly, up that long and steep hill to get back.
To recap:
Electric Scooter: 2.83*10^6 joules
Bicycle: 5.76*10^6 joules
Walking: 17.5*10^6 joules
smart fortwo: 28.9*10^6 joules
Land Rover LR3 HSE: 54.2*10^6 joules
Update: A very interesting analysis of the bicycle versus electric bicycle (scooter) energy requirements that includes life-cycle energy consideration done as a term paper is available here.
Sunday, August 23, 2009
The CNW Research - Pacific Institute - Slate Magazine kerfuffle
Let me start by saying I've wanted for a long time to use "kerfuffle" in a blog post. The contretemps that's the subject of this post fits the word perfectly. You may remember a few years back that a meme went around stating that the "lifetime energy usage" of a Hummer was less than that of a Prius. As the rumblings had it, this was primarily because of the energy required to manufacture, carry, and dispose of the Prius' battery pack.
The origin of this meme was a report by an entity called CNW Research that is, as best I can tell, a marketing research firm. The report claims to use 3,000 data points to put a price tag on the "dust to dust" (inception of design to manufacture to use to disposal and recycling of the vehicle at its "end of life") energy of a wide variety of vehicles. It's stated that they even include the fuel used driving to work by the employees of the vehicle's manufacturer in their calculations.
They rank many vehicles in a tremendous variety of categories but the phrase that caught on was that the Prius uses more energy from dust to dust than a Hummer.This is despite the fact that the report itself puts these two vehicles in separate categories. CNW Research recommends that the report be used to compare vehicles within a category, not across categories.
On its face, this result seems ludicrous. And Pacific Institute (here) and Slate Magazine (here), among others have strongly criticized the results. CNW Research has defended their results at pages linked here.
Instinct often leads one astray in the field of energy, let's take a brief look. The actual report is available at CNW Research's site in pdf and Excel versions. The pdf is 458 pages and 3 MB so it's a chore.
That said, there are some telling indications to start with, among which are the misuse of units (watts, kilowatt hours, joules, etc.). In fact, they refer to "juelles." Not confidence-inspiring, to say the least. There are strange estimates of vehicle lifetime years of use (e.g., for the H1 34.96 years) with no indication of the source of the number. These numbers are critical because the ultimate number they give is energy cost per mile. The denominator, miles, is found by taking lifetime in years and multiplying by miles per year. There's no indication of the source of either number (other than "CNW Research").
It appears that they use several resales to secondary owners in their cost calculations, though this clearly has nothing whatsoever to do with energy expenditure - I doubt that the writing of a check, and a trip to DMV are significant energy expenditures in the final analysis. And cost is a telling indication. For example, the Prius is stated to have a "life-cycle energy cost" of $3.25/mile. Using the lifetime mileage of 109,000 miles, that means that, exclusive of the materials cost of the Prius, profit for the manufacturer and the various suppliers, distributors, etc., the energy from cradle to grave of a Prius costs over $350,000.
Now, suppose I buy a loaded Prius for $25,000 and drive it 109,000 miles. Using the IRS rate, a decent proxy for all costs of driving (including depreciation, maintence, etc.) and excessive if anything for the Prius, the total cost (not adjusted for time value of money) would be $84,950. Even assuming 100% of that is energy costs, who's paying the other $269,300?
I will acknowledge that "society" pays a significant amount in the form of road maintenance and other public goods. And CNW Research claims to account for these. But it's impossible that this would account for the enormous discrepancy.
All that said, it's clear that CNW Research has invested a lot of time and effort and gathered a spectacular amount of data. I'd like them to be open with it because the conclusions they've reached, correct or incorrect, are quite important. I don't accuse them of bias on the basis of funding, I don't see that kind of skew in their analysis and they claim to have funded it internally. Fair enough, I'll take them at their word.
If this information were to presented as a peer-reviewed publication and the data made available, it would be extremely valuable. I understand that CNW Research wants to profit from their efforts and I'm sympathetic to the profit motive. But the results, as presented, leave ample room for skepticism at best and dismissal at worst. To their credit, they have extensive appendices and answer many questions emailed by readers. Unfortunately, they don't clear up the points listed above.
The origin of this meme was a report by an entity called CNW Research that is, as best I can tell, a marketing research firm. The report claims to use 3,000 data points to put a price tag on the "dust to dust" (inception of design to manufacture to use to disposal and recycling of the vehicle at its "end of life") energy of a wide variety of vehicles. It's stated that they even include the fuel used driving to work by the employees of the vehicle's manufacturer in their calculations.
They rank many vehicles in a tremendous variety of categories but the phrase that caught on was that the Prius uses more energy from dust to dust than a Hummer.This is despite the fact that the report itself puts these two vehicles in separate categories. CNW Research recommends that the report be used to compare vehicles within a category, not across categories.
On its face, this result seems ludicrous. And Pacific Institute (here) and Slate Magazine (here), among others have strongly criticized the results. CNW Research has defended their results at pages linked here.
Instinct often leads one astray in the field of energy, let's take a brief look. The actual report is available at CNW Research's site in pdf and Excel versions. The pdf is 458 pages and 3 MB so it's a chore.
That said, there are some telling indications to start with, among which are the misuse of units (watts, kilowatt hours, joules, etc.). In fact, they refer to "juelles." Not confidence-inspiring, to say the least. There are strange estimates of vehicle lifetime years of use (e.g., for the H1 34.96 years) with no indication of the source of the number. These numbers are critical because the ultimate number they give is energy cost per mile. The denominator, miles, is found by taking lifetime in years and multiplying by miles per year. There's no indication of the source of either number (other than "CNW Research").
It appears that they use several resales to secondary owners in their cost calculations, though this clearly has nothing whatsoever to do with energy expenditure - I doubt that the writing of a check, and a trip to DMV are significant energy expenditures in the final analysis. And cost is a telling indication. For example, the Prius is stated to have a "life-cycle energy cost" of $3.25/mile. Using the lifetime mileage of 109,000 miles, that means that, exclusive of the materials cost of the Prius, profit for the manufacturer and the various suppliers, distributors, etc., the energy from cradle to grave of a Prius costs over $350,000.
Now, suppose I buy a loaded Prius for $25,000 and drive it 109,000 miles. Using the IRS rate, a decent proxy for all costs of driving (including depreciation, maintence, etc.) and excessive if anything for the Prius, the total cost (not adjusted for time value of money) would be $84,950. Even assuming 100% of that is energy costs, who's paying the other $269,300?
I will acknowledge that "society" pays a significant amount in the form of road maintenance and other public goods. And CNW Research claims to account for these. But it's impossible that this would account for the enormous discrepancy.
All that said, it's clear that CNW Research has invested a lot of time and effort and gathered a spectacular amount of data. I'd like them to be open with it because the conclusions they've reached, correct or incorrect, are quite important. I don't accuse them of bias on the basis of funding, I don't see that kind of skew in their analysis and they claim to have funded it internally. Fair enough, I'll take them at their word.
If this information were to presented as a peer-reviewed publication and the data made available, it would be extremely valuable. I understand that CNW Research wants to profit from their efforts and I'm sympathetic to the profit motive. But the results, as presented, leave ample room for skepticism at best and dismissal at worst. To their credit, they have extensive appendices and answer many questions emailed by readers. Unfortunately, they don't clear up the points listed above.
Embarrassed to be conservative
I find myself going "off topic" more frequently on this blog as it becomes an avenue for me to express opinions on sociological and political matters. This may cause some dismay for those who've followed me to understand how it's possible to get 21 m.p.g. in a Land Rover or the effect on U.S. primary energy consumption should everyone switch to hypermiling. Sorry.
As I've intimated from time to time, I'm not a big government liberal. If anything, my political philosophy revolves around small-l libertarianism. That is, personal responsibility for outcomes and minimal government involvement in the day-to-day lives of the populace. I don't tend to support the attitude of "there's something we don't like, let's involve the government in the solution," and thus could be considered "conservative" in a sense. But what is it I'd like to conserve?
I'd like to conserve the natural resources necessary for both the advancement of civilization and the health of the entire ecology. I'd like to conserve our financial resources to enable us to invest in our future. I'd like to conserve our freedom to act in our own best interest so long as it can be done without the use of force, the threat of force, fraud, or coercion. In a nutshell, I believe that's what conservatism should mean.
I don't want to waste time and bytes on the truly wacko birthers and the like, though I'd point out that those who decry that conservatism leads to birther morons must then acknowledge that liberalism leads to truther fools (though I'll concede that there are nut cases of the black helicopter variety in the truther movement as well). In any case, my problem is with what has now become "mainstream" conservatism as represented by James Inhofe, Michelle Malkin, Rush Limbaugh, Glen Beck, Sarah Palin, George Will, etc.
These spokespersons and their ilk have turned the political discourse into a win at all costs war. Among the casualties of this war are civility, honesty, integrity, and reason. The "death panels" are one of the latest examples of the intellectual corruption of the conservative movement. As Mark Hoofnagle states in his Denialism blog post, there is a debate to be had on health care, but the idiotic shrieking and bald faced lies of the so-called conservatives are preventing us from having it.
Similarly, how to proceed to a world of lower energy conversion rates, given the extremely low rates and high populations of the developing world and their reasonable desire to increase those rates, is a complex topic requiring reasoned discussion and rational action. Whether one comes at the energy issue from the point of view of peak oil and resource depletion, climate change, or both, it's clear to any thinking person that we can't have nine billion people converting primary energy to heat at the U.S. rate of 11 kilowatts per capita. This would lead to a complete collapse of civilization, either through self-poisoning or complete resource depletion, or both, economic theory notwithstanding.
Yet the Moranos and the Inhofes continually propagate all manner of distortions implying that business as usual is the answer.
I'm not a big fan of categorizing my political philosophy with a single word, but if those I've mentioned are conservative, I most certainly would be embarrassed for the word to be applied to me.
As I've intimated from time to time, I'm not a big government liberal. If anything, my political philosophy revolves around small-l libertarianism. That is, personal responsibility for outcomes and minimal government involvement in the day-to-day lives of the populace. I don't tend to support the attitude of "there's something we don't like, let's involve the government in the solution," and thus could be considered "conservative" in a sense. But what is it I'd like to conserve?
I'd like to conserve the natural resources necessary for both the advancement of civilization and the health of the entire ecology. I'd like to conserve our financial resources to enable us to invest in our future. I'd like to conserve our freedom to act in our own best interest so long as it can be done without the use of force, the threat of force, fraud, or coercion. In a nutshell, I believe that's what conservatism should mean.
I don't want to waste time and bytes on the truly wacko birthers and the like, though I'd point out that those who decry that conservatism leads to birther morons must then acknowledge that liberalism leads to truther fools (though I'll concede that there are nut cases of the black helicopter variety in the truther movement as well). In any case, my problem is with what has now become "mainstream" conservatism as represented by James Inhofe, Michelle Malkin, Rush Limbaugh, Glen Beck, Sarah Palin, George Will, etc.
These spokespersons and their ilk have turned the political discourse into a win at all costs war. Among the casualties of this war are civility, honesty, integrity, and reason. The "death panels" are one of the latest examples of the intellectual corruption of the conservative movement. As Mark Hoofnagle states in his Denialism blog post, there is a debate to be had on health care, but the idiotic shrieking and bald faced lies of the so-called conservatives are preventing us from having it.
Similarly, how to proceed to a world of lower energy conversion rates, given the extremely low rates and high populations of the developing world and their reasonable desire to increase those rates, is a complex topic requiring reasoned discussion and rational action. Whether one comes at the energy issue from the point of view of peak oil and resource depletion, climate change, or both, it's clear to any thinking person that we can't have nine billion people converting primary energy to heat at the U.S. rate of 11 kilowatts per capita. This would lead to a complete collapse of civilization, either through self-poisoning or complete resource depletion, or both, economic theory notwithstanding.
Yet the Moranos and the Inhofes continually propagate all manner of distortions implying that business as usual is the answer.
I'm not a big fan of categorizing my political philosophy with a single word, but if those I've mentioned are conservative, I most certainly would be embarrassed for the word to be applied to me.
Wednesday, August 12, 2009
The law of dimishing returns, the Chevy Volt, gas mileage, and hot air
The Chevy Volt, expected to hit the market in 2010 is claimed to achieve 230 m.p.g. in city driving. Is this possible? If so, how significant is it? Over at one of my favorite haunts, Ecomodder.com, Benjamin posted a blog entry about the Volt and the claims for it.As is my nature, I was compelled to dig into the numbers. I commented there that it sounds suspicious. The claims for the Volt are that it will achieve "up to 40 miles" on electricity only and that it will achieve an efficiency on electricity only of 25 kilowatt hours per 100 miles on the EPA city cycle. This is stated to cost between $0.75 and $2.50 depending on electric rates. Interesting.
This is saying that, when using only electricity, the vehicle will have an energy cost of $.0075 and $.025 per mile. That is, between three quarters of a cent and 2 and a half cents per mile. Now, I'm currently getting 21 m.p.g. and spending about $0.15, i.e., fifteen cents per mile on energy. Comparing to the low end of the electrical cost, I'm spending 20 times as much on energy. At the high end, it's six times as much. So multiplying 21 m.p.g. by 6 and by 20, you'd infer that the Volt is achieving something from 126 m.p.g. to 420 m.p.g. just on a cost of energy basis. 230 m.p.g. is in this range, but this isn't very enlightening. Let's try something else.
We'll work with the 25 kilowatt hours (25 kWH) per 100 miles. A kilowatt hour of electricity is 3.6 megajoules, so 25 kWH is 90 megajoules. Since a gallon of gasoline will release about 125 megajoules of thermal energy upon oxidation, we can say that the Volt will go 100 miles on the energy contained in (90/125) or 0.72 gallons of gasoline, thus getting roughly the equivalent of 100/0.72 or about 139 m.p.g. (or, as Doug Pelmear would say, 139 MPGe).
So where did 230 m.p.g. come from? I'm not sure. One possibility is that they look at, say, a 50 mile trip, figure 40 miles on the electric motor and don't count that energy expenditure, then travel the remaining 10 miles on a gasoline engine that gets 46 m.p.g. while powering a generator to propel the car and recharge the battery. Conveniently, that would indicate travelling 50 miles on 10/46=0.217 gallons, or 230 m.p.g. At this point, I don't know.
In any case, suppose that we do have such a vehicle. What would it mean? In an earlier post I went into some detail on the fact that, the worse the gas mileage being achieved, that is, the lower the m.p.g. the more fuel is saved by relatively small improvements in that number. This result is surprising to some because miles per gallon is really not the best way to directly look at efficiency. The better way is gallons per mile, the inverse.* The Volt will illustrate the other end of the spectrum from that described in my previous post.
Let's say I trade a Toyota Yaris, where I was getting 30 m.p.g. driving mostly in the city for a Chevy Volt where I now get "the equivalent of" 230 m.p.g. Suppose I drive 10,000 miles per year. I'll go from burning 333 gallons of fuel to the equivalent of 43.5 gallons, saving 290 gallons.
Meanwhile, my Doppelgänger is driving his LR3 HSE, mostly in the city, and getting 15 m.p.g. He uses 667 gallons to drive 10,000 miles. He trades it in on a MINI Cooper and gets 30 m.p.g., using 333 gallons in the course of his 10,000 miles of driving. He saves 333 gallons, 43 more than I did by going from 30 m.p.g. to 230 m.p.g. This is the law of diminishing returns in action.
From a person who coasts to the cross street from his driveway before turning on the car to save a milliliter or two of fuel, it might seem odd to read something apparently dismissive of such extraordinarily good fuel economy. But I'm not dismissing it, only attempting to put it into perspective as to what's being achieved and where the big savings lie. In fact, my hat's off to Chevy for bringing this ultra-efficient vehicle to market but they need to be clear with their claims.
* In the Great White North, where civilized people use the SI ("metric") system, fuel economy is rated in liters per 100 kilometers (though "liter" isn't strictly a SI unit). My 21 m.p.g. rating turns to 11.2 liters per 100 kilometers. The Volt's stated 230 m.p.g. would be 1.02 liters per 100 kilometers.
Update: Rhett, over at DOT PHYSICS, has made a very thorough analysis of the Volt. Take a look!
Update 2: A better debunking than mine of the Chevy Volt m.p.g. claim is at Good Math, Bad Math. I've added this great blog to my blog roll. You're welcome.
By the way, I found Good Math, Bad Math by typing the conversion from 230 m.p.g. into the Google calculator. It made the conversion AND came up with the blog site. You have to love the Google folks. Even if you equate them to the Borg.
Update 3: Apparently, from reading the comments to the Good Math, Bad Math post linked above, Chevy is "just following orders," i.e., they're going by the tentative rules promulgated by the EPA for the fuel economy ratings of plug-in hybrids. I still think Chevy should be clear. As Rhett shows on his Dot Physics site (also linked above) if you pull out of your driveway and drive 230 miles, you'll use way more than a gallon of gas.
Saturday, August 08, 2009
Time out
I am by nature a cynical and pessimistic person (not the same thing - it's said that an optimist is a father who will loan his teenager the car, a pessimist is one who won't, and a cynic is one who did). I don't say this to brag, I actually try to at least act as if I'm not. This blog covers topics that will, if major changes aren't forthcoming (and there's no reason to believe they will be), result in unprecedented trauma in our so-called social contract. Now, maybe we'll adapt and the result will be a stable and sustainable societal arrangement, albeit at a lower level of energy conversion. Maybe it will be a Mad Max world. I'd like to hope the former, but my makeup makes me dubious.
Thus, it's significant to me when I find something that makes me feel that it's not all bad. A few months ago, I was watching a youtube video of Leo Kottke, a guitarist I've admired for years and seen on multiple occasions. Youtube suggested I might want to see videos featuring Tommy Emmanuel, of whom I'd never heard. I didn't click on them for the first few times they came up next to Leo, but I finally did. Let me say that Tommy's talent, skill, and love of music have become one of the things that makes me believe there's good in the world and things worth preserving.
I drove four and a half hours to see Tommy Emmanuel perform in Exeter, CA and, though I anticipated that it would be a wonderful experience, I tremendously underestimated how moving it would be. His videos are all over youtube and, since this is a non-commercial blog, I've decided to put one here. It's called "Those Who Wait." I apologize in advance for no physics, vehicle, energy, or gasoline content but I feel compelled to share my wonder at this uniquely talented and genuinely beautiful musician and songwriter (the composition featured here is his). Click on it, you'll thank me. If you're wondering if he's capable of something a little more up-tempo, check out his Guitar Boogie. If your jaw doesn't hit the floor, you have more self-control than I.
Thus, it's significant to me when I find something that makes me feel that it's not all bad. A few months ago, I was watching a youtube video of Leo Kottke, a guitarist I've admired for years and seen on multiple occasions. Youtube suggested I might want to see videos featuring Tommy Emmanuel, of whom I'd never heard. I didn't click on them for the first few times they came up next to Leo, but I finally did. Let me say that Tommy's talent, skill, and love of music have become one of the things that makes me believe there's good in the world and things worth preserving.
I drove four and a half hours to see Tommy Emmanuel perform in Exeter, CA and, though I anticipated that it would be a wonderful experience, I tremendously underestimated how moving it would be. His videos are all over youtube and, since this is a non-commercial blog, I've decided to put one here. It's called "Those Who Wait." I apologize in advance for no physics, vehicle, energy, or gasoline content but I feel compelled to share my wonder at this uniquely talented and genuinely beautiful musician and songwriter (the composition featured here is his). Click on it, you'll thank me. If you're wondering if he's capable of something a little more up-tempo, check out his Guitar Boogie. If your jaw doesn't hit the floor, you have more self-control than I.
Sunday, August 02, 2009
Why "Hamiltonian Function"?
Physicists (of which I am most emphatically not one) will instantly recognize the "Hamiltonian." It's not about a horse race (though I stuck "function" on in the name to distinguish it from that) nor does it refer to a Founding Father. Rather, the Hamiltonian is a function that represents the total energy of a system utilizing a reformulation of Newtonian mechanics called, unsurprisingly, Hamiltonian mechanics. Since this blog is nominally about energy, how to minimize its expenditure, and take maximum advantage the energy I convert, the Hamiltonian Function as a title seems appropriate to me.
Though it typically doesn't make a particular problem easier to solve, it's considered that the Hamiltonian of a system is capable of providing deeper insight into the nature of the system under consideration than the second order differential equations of Newtonian mechanics. This is particularly true when the system involves quantum mechanical considerations, though it is completely general in its application. I'd be flattering myself to contend that my little blog is capable of providing deep insights, but I do hope that it can provide a different point of view and be thought provoking.
Though it typically doesn't make a particular problem easier to solve, it's considered that the Hamiltonian of a system is capable of providing deeper insight into the nature of the system under consideration than the second order differential equations of Newtonian mechanics. This is particularly true when the system involves quantum mechanical considerations, though it is completely general in its application. I'd be flattering myself to contend that my little blog is capable of providing deep insights, but I do hope that it can provide a different point of view and be thought provoking.
Playing with an iPhone
I dumped my forever locking up Samsung Omnia for an iPhone 3Gs. As most will know, one of the major selling points of the iPhone (and a good one at that, though some stridently disagree) is the availability of an ever-growing "app store." I've installed six apps so far, but this post is about the Wavefront Labs Accelerator Data Pro and Cross-Discipline Technology, LLC Gforce apps. These apps take the data from the three axis accelerometer in the iPhone and display it or log it. I thought it would be interesting to document exactly how slowly I accelerate, though I already had a pretty good idea from logging speed vs. time in five second intervals as mentioned in this post.
I've used the Gforce app more frequently because, well, I'm driving and the display is much more intuitive to understand at a glance (click on the photo for an enlarged view). It's capable of holding the peak in longitudinal and transverse axes for a user-set amount of time and of sounding an alarm when user-set limits are exceeded in either axis. The Acceleration Data Pro is capable of saving data to a file and exporting for subsequent analysis. I intend to so use it but have not done so yet.
As readers of this blog might imagine, my positive acceleration numbers are quite small, rarely exceeding 0.1 g (0.98 meters/sec^2), though the first movement from a stop is typically about 0.15 g. I estimate that the average acceleration up to speed is about 0.055 g. To get a feel for this, that means I'm gaining about 1.2 miles/hour in speed with each second. Using that acceleration, I get to 55 miles/hour in about 45.6 seconds. This is somewhat faster than the results I got from timing, referred to above. I don't know if I'm getting more rambunctious in my application of throttle (doubtful, judging from the reactions of those with whom I share the road) or I'm "guesstimating" the average acceleration from the iPhone inaccurately.
Probably of more interest, there's a curved ramp from the 605 freeway northbound to the 91 freeway eastbound that I take at a speed, v, of about 50 miles/hour (22.35 meters/second). The Gforce shows a centripetal acceleration, a, of about 0.38 g, or 3.724 meters/second^2. Now, since a=v^2/r, where r is the radius of the path described by my vehicle (for a very nice lesson on this topic, see Rhett Alain's Dot Physics entry), I can estimate that the radius of the ramp is about 134 meters. How can you not love the ability of the iPhone to measure the radius of curvature of a freeway on-ramp?
The ramp has a recommended maximum speed of 35 miles/hour (I maintain 50 m.p.h. because I don't want to apply brakes). Working backwards, this means that CalTrans has designed the ramp for a recommended centripetal acceleration of about 0.19 g. They should put that on the sign!
Starting early in my first high school physics class and reemphasized ever since, when looking at any physical situation, when in doubt, F=m*a. That is, force equals mass times acceleration, Newton's second law (well, sort of - Newton actually framed it as net force equals rate of change of momentum but it's the same thing). Let's apply it here. The mass of my Land Rover LR3 HSE is about 2,676 kilograms, and I take that curve at about 0.38 g or 3.72 meters/second^2. This means F is about 9966 Newtons, or about 2,240 pounds. Note that this is over 10 times the force required to move the LR3 down the road at 55 m.p.h. and it's applied by the road to the vehicle through the tires. No wonder they wear out!
Update: To really see what can be done with the iPhone and its acclerometer and GPS, see Michael Koppelman's exploits with an iPhone in a model rocket.
Update 2: I haven't done any programming since about 1989, and that was meager. My last (semi) serious bout with programming was in 1980. I wonder how hard it would be to write and install a program for the iPhone that would provide average acceleration in each axis from a start to a stop time, or average over user set intervals, say, every second?
I've used the Gforce app more frequently because, well, I'm driving and the display is much more intuitive to understand at a glance (click on the photo for an enlarged view). It's capable of holding the peak in longitudinal and transverse axes for a user-set amount of time and of sounding an alarm when user-set limits are exceeded in either axis. The Acceleration Data Pro is capable of saving data to a file and exporting for subsequent analysis. I intend to so use it but have not done so yet.As readers of this blog might imagine, my positive acceleration numbers are quite small, rarely exceeding 0.1 g (0.98 meters/sec^2), though the first movement from a stop is typically about 0.15 g. I estimate that the average acceleration up to speed is about 0.055 g. To get a feel for this, that means I'm gaining about 1.2 miles/hour in speed with each second. Using that acceleration, I get to 55 miles/hour in about 45.6 seconds. This is somewhat faster than the results I got from timing, referred to above. I don't know if I'm getting more rambunctious in my application of throttle (doubtful, judging from the reactions of those with whom I share the road) or I'm "guesstimating" the average acceleration from the iPhone inaccurately.
Probably of more interest, there's a curved ramp from the 605 freeway northbound to the 91 freeway eastbound that I take at a speed, v, of about 50 miles/hour (22.35 meters/second). The Gforce shows a centripetal acceleration, a, of about 0.38 g, or 3.724 meters/second^2. Now, since a=v^2/r, where r is the radius of the path described by my vehicle (for a very nice lesson on this topic, see Rhett Alain's Dot Physics entry), I can estimate that the radius of the ramp is about 134 meters. How can you not love the ability of the iPhone to measure the radius of curvature of a freeway on-ramp?
The ramp has a recommended maximum speed of 35 miles/hour (I maintain 50 m.p.h. because I don't want to apply brakes). Working backwards, this means that CalTrans has designed the ramp for a recommended centripetal acceleration of about 0.19 g. They should put that on the sign!
Starting early in my first high school physics class and reemphasized ever since, when looking at any physical situation, when in doubt, F=m*a. That is, force equals mass times acceleration, Newton's second law (well, sort of - Newton actually framed it as net force equals rate of change of momentum but it's the same thing). Let's apply it here. The mass of my Land Rover LR3 HSE is about 2,676 kilograms, and I take that curve at about 0.38 g or 3.72 meters/second^2. This means F is about 9966 Newtons, or about 2,240 pounds. Note that this is over 10 times the force required to move the LR3 down the road at 55 m.p.h. and it's applied by the road to the vehicle through the tires. No wonder they wear out!
Update: To really see what can be done with the iPhone and its acclerometer and GPS, see Michael Koppelman's exploits with an iPhone in a model rocket.
Update 2: I haven't done any programming since about 1989, and that was meager. My last (semi) serious bout with programming was in 1980. I wonder how hard it would be to write and install a program for the iPhone that would provide average acceleration in each axis from a start to a stop time, or average over user set intervals, say, every second?
Tuesday, July 28, 2009
Getting from here to there
My previous post dealt with business jets. It was discouraging in that for a lot of money, you purchase the opportunity to use a lot of fuel on very expensive trips. I didn't get into so-called "direct operating costs" which include such items as engine inspection/overhaul reserve, maintenance, pilot costs (for a professional), etc. not to mention hangaring, insurance, and more, but suffice it to say that these aren't trivial for a "bizjet."
So who flies on a bizjet and why? And, for the matter of that, how should I decide how to get from here to there? I determined to apply logic and spreadsheets to the questions. I decided that the relevant factors are: speed; convenience; cost; and fuel (carbon). I subdivided convenience into: location near departure point and destination; security check hassles; schedule convenience; schedule reliability; and baggage limitations. I rated five methods of getting from here to there: airlines; my Land Rover LR3 HSE; the Phenom 100 of the previous post; my Saratoga; and an intercity bus. Sadly, having investigated intercity rail for a couple of trips, for most purposes that mode is completely impractical. There are exceptions of course, for example, downtown Los Angeles to downtown San Diego.
For each analyzed mode I used various numbers - some objective (e.g., speed, fuel economy) and some subjective (e.g., convenience) and scaled the rating for each transportation method in each category with the best rated in the category as "1." Then I assigned weights to each factor and summed them to determine a "merit index" for each mode of transport. I then played with the weights to see what considerations would result in which mode being the preferred choice.
For me, on an intermediate length business trip (say, Long Beach to Salt Lake City), I figured the weighting factors to be: speed - 0.4; convenience - 0.25; cost - 0.25; fuel burn (carbon emitted) - 0.1. Using these, the airline trip has the highest merit index, followed by the LR3, the Phenom 100, the bus, and finally the Saratoga. This is most interesting, in that I made just such a trip a few weeks ago and took the Saratoga.
So what weights result in choosing the Saratoga? If the biggest factor is convenience followed by speed as about half as important, cost of little importance and fuel of trivial importance, the Saratoga wins. Similarly, if speed and convenience are the only factors and speed is half again as important as convenience, the Phenom 100 is the way to go. Note that this literally means "money and fuel are no object, get me there fast and easily."
Looking for a combination resulting in driving being the choice, convenience dominates with everything else relatively minor. I'm in no hurry, not too concerned about cost and fuel. Finally, what would motivate me to take the bus? If my main concern is fuel burn and minimizing carbon footprint, with convenience and speed not among my considerations (not to mention how I smell when I arrive) then the bus is my choice.
It's clear that this analysis is of limited practical applicability - I certainly wouldn't take a bus or drive to New York City, nor take my Saratoga to Glendale, CA. And to call the methodology simplistic would be an insult to simpletons. Furthermore, it leaves out the "because I wanted to" factor that motivates the Saratoga trips. I'm suspicious that such a factor may also be operative in many bizjet flights. It's built around a typical business trip for my company, say, to Phoenix, Sacramento, Salt Lake City, etc. But even at that, it provides a valid comparison for bizjet vs. airline to New York or Saratoga vs. driving to Las Vegas.
The biggest revelation coming from this exercise is the wide range of considerations that lead to the airline being the preferred choice. Obviously nothing earth shattering, but it has helped me to crystallize my thoughts and to understand how I'd have to rationalize... er... justify... ummm that is, what considerations would have to be most important for me to make the purchase of a bizjet something I "couldn't afford not to do."
So who flies on a bizjet and why? And, for the matter of that, how should I decide how to get from here to there? I determined to apply logic and spreadsheets to the questions. I decided that the relevant factors are: speed; convenience; cost; and fuel (carbon). I subdivided convenience into: location near departure point and destination; security check hassles; schedule convenience; schedule reliability; and baggage limitations. I rated five methods of getting from here to there: airlines; my Land Rover LR3 HSE; the Phenom 100 of the previous post; my Saratoga; and an intercity bus. Sadly, having investigated intercity rail for a couple of trips, for most purposes that mode is completely impractical. There are exceptions of course, for example, downtown Los Angeles to downtown San Diego.
For each analyzed mode I used various numbers - some objective (e.g., speed, fuel economy) and some subjective (e.g., convenience) and scaled the rating for each transportation method in each category with the best rated in the category as "1." Then I assigned weights to each factor and summed them to determine a "merit index" for each mode of transport. I then played with the weights to see what considerations would result in which mode being the preferred choice.
For me, on an intermediate length business trip (say, Long Beach to Salt Lake City), I figured the weighting factors to be: speed - 0.4; convenience - 0.25; cost - 0.25; fuel burn (carbon emitted) - 0.1. Using these, the airline trip has the highest merit index, followed by the LR3, the Phenom 100, the bus, and finally the Saratoga. This is most interesting, in that I made just such a trip a few weeks ago and took the Saratoga.
So what weights result in choosing the Saratoga? If the biggest factor is convenience followed by speed as about half as important, cost of little importance and fuel of trivial importance, the Saratoga wins. Similarly, if speed and convenience are the only factors and speed is half again as important as convenience, the Phenom 100 is the way to go. Note that this literally means "money and fuel are no object, get me there fast and easily."
Looking for a combination resulting in driving being the choice, convenience dominates with everything else relatively minor. I'm in no hurry, not too concerned about cost and fuel. Finally, what would motivate me to take the bus? If my main concern is fuel burn and minimizing carbon footprint, with convenience and speed not among my considerations (not to mention how I smell when I arrive) then the bus is my choice.
It's clear that this analysis is of limited practical applicability - I certainly wouldn't take a bus or drive to New York City, nor take my Saratoga to Glendale, CA. And to call the methodology simplistic would be an insult to simpletons. Furthermore, it leaves out the "because I wanted to" factor that motivates the Saratoga trips. I'm suspicious that such a factor may also be operative in many bizjet flights. It's built around a typical business trip for my company, say, to Phoenix, Sacramento, Salt Lake City, etc. But even at that, it provides a valid comparison for bizjet vs. airline to New York or Saratoga vs. driving to Las Vegas.
The biggest revelation coming from this exercise is the wide range of considerations that lead to the airline being the preferred choice. Obviously nothing earth shattering, but it has helped me to crystallize my thoughts and to understand how I'd have to rationalize... er... justify... ummm that is, what considerations would have to be most important for me to make the purchase of a bizjet something I "couldn't afford not to do."
Sunday, July 26, 2009
Just how bad are business jets?
As regular readers will know, I'm a pilot and the owner of a Piper Saratoga. That's a single engine propeller driven aircraft. In it, I get on the order of 11 statute miles per gallon and cruise at around 190 miles per hour. With no headwind, I can fly from my base in Long Beach, CA to Colorado Springs to see my brother and his family without a fuel stop, though I can rarely fly back non-stop. Like most pilots ("most" meaning, I would guess, greater than 95%) I wouldn't mind flying something faster, quieter, and with greater range. I'll also add more comfort (pressurization) and more all-weather capability (fully deiced) to the wish list.
In the current economic situation, traveling in business jets has become a very guilty pleasure indeed - witness the opprobrium heaped upon the GM and Chrysler executives who took their corporate jets to Washington to plead for bail out money. Suitably chastened by the Congressional panelists - who never waste taxpayer money - they drove hybrids to their next Congressional begging session. In the end, however, both companies entered and exited bankruptcy. I'm sure the executive jets were the proximate cause. So, are private jets really so bad?
Yesterday I had a chance to catch a ride in an Embraer Phenom 100, a so-called "very light jet." It's certificated for single pilot operation, and operates up to 41,000 feet, above almost all weather, at about 415 miles per hour. At that speed its two Pratt & Whitney PW617F-E turbofans burn about 704 pounds of Jet A fuel per hour, delivering a fuel economy of about 4 miles per gallon. Its full fuel range (with full fuel you'll be able to carry about 580 pounds of passengers and baggage not including the pilot) is about 1,400 statute miles in no-wind conditions.
The Phenom 100 cabin is quite comfortable; a passenger could sleep, work, converse comfortably with associates, or listen to Sirius satellite radio. It treats its passengers as those who get around in business jets expect to be treated (or, not being such a person, so it seems to me). Admittedly, it lacks the quiche heater and bidet one finds in higher end jets, but the interior was designed by BMW Group DesignworksUSA so you won't need to apologize for it. It has six seats - two in the cockpit and four in the cabin, plus a potty that can be used as a seventh seat. Assuming that the pilot is a professional, the five remaining seats mean that the aircraft can deliver something like 20 passenger seat miles per gallon. If I'm the pilot and I have five passengers, the figure is 24 seat miles per gallon. You'll have to queue up to purchase yours for about $3.6M.
Now, were my blog to catch on, the ad revenues to flow like water, and my bank account to swell like a balloon, I've always felt that the best, fastest, longest range airplane FLYABLE BY A SINGLE PILOT would be my ultimate ride. It's a short list of candidates and the Phenom 100 would be on it. Just how bad is this in terms of fuel consumption? In 2008, it's estimated that U.S. air carriers delivered about 58 seat miles per gallon. The Boeing 737-800 gets about 80 seat miles per gallon. If I look at my Land Rover LR3 as a five seat vehicle, I'm currently getting about 105 seat miles per gallon, though for 95% of the miles, I'm getting 21 passenger miles per gallon. Were I to use the Phenom 100 as I use my Saratoga it also would have a single occupant for the vast majority of its flight hours, thus providing four passenger miles per gallon.
I have to concede that this is a depressing post. It's difficult for me to enumerate these facts and then desire to purchase a jet. By no means am I financially able to contemplate such a purchase at this point anyway, but it had been nice to dream.
In the current economic situation, traveling in business jets has become a very guilty pleasure indeed - witness the opprobrium heaped upon the GM and Chrysler executives who took their corporate jets to Washington to plead for bail out money. Suitably chastened by the Congressional panelists - who never waste taxpayer money - they drove hybrids to their next Congressional begging session. In the end, however, both companies entered and exited bankruptcy. I'm sure the executive jets were the proximate cause. So, are private jets really so bad?
Yesterday I had a chance to catch a ride in an Embraer Phenom 100, a so-called "very light jet." It's certificated for single pilot operation, and operates up to 41,000 feet, above almost all weather, at about 415 miles per hour. At that speed its two Pratt & Whitney PW617F-E turbofans burn about 704 pounds of Jet A fuel per hour, delivering a fuel economy of about 4 miles per gallon. Its full fuel range (with full fuel you'll be able to carry about 580 pounds of passengers and baggage not including the pilot) is about 1,400 statute miles in no-wind conditions.
The Phenom 100 cabin is quite comfortable; a passenger could sleep, work, converse comfortably with associates, or listen to Sirius satellite radio. It treats its passengers as those who get around in business jets expect to be treated (or, not being such a person, so it seems to me). Admittedly, it lacks the quiche heater and bidet one finds in higher end jets, but the interior was designed by BMW Group DesignworksUSA so you won't need to apologize for it. It has six seats - two in the cockpit and four in the cabin, plus a potty that can be used as a seventh seat. Assuming that the pilot is a professional, the five remaining seats mean that the aircraft can deliver something like 20 passenger seat miles per gallon. If I'm the pilot and I have five passengers, the figure is 24 seat miles per gallon. You'll have to queue up to purchase yours for about $3.6M.Now, were my blog to catch on, the ad revenues to flow like water, and my bank account to swell like a balloon, I've always felt that the best, fastest, longest range airplane FLYABLE BY A SINGLE PILOT would be my ultimate ride. It's a short list of candidates and the Phenom 100 would be on it. Just how bad is this in terms of fuel consumption? In 2008, it's estimated that U.S. air carriers delivered about 58 seat miles per gallon. The Boeing 737-800 gets about 80 seat miles per gallon. If I look at my Land Rover LR3 as a five seat vehicle, I'm currently getting about 105 seat miles per gallon, though for 95% of the miles, I'm getting 21 passenger miles per gallon. Were I to use the Phenom 100 as I use my Saratoga it also would have a single occupant for the vast majority of its flight hours, thus providing four passenger miles per gallon.
I have to concede that this is a depressing post. It's difficult for me to enumerate these facts and then desire to purchase a jet. By no means am I financially able to contemplate such a purchase at this point anyway, but it had been nice to dream.
Saturday, July 18, 2009
Powerkuff
In May, I attended the Cleantech conference in Houston, TX. While at one of the sessions, a presenter made a passing remark (and held his example up for us to see) about the "Powerkuff." This simple device wraps around the electrical service to my house at the service panel and wirelessly sends a continuous stream of data on power use. Added to information on price, it allows me to see just how much electricity is being used and how much money is being spent.
The device is fairly foolproof, and the output can be read on a small box and sent to a proprietary program through a USB port to a graphical display on the computer, showing power as a function of time. It comes complete and shipped for about $109, and the software to upload usage data to my computer is a free download on the Powerkuff web site. And Chuck Wagner is very helpful and accessible. The software is quite rudimentary, data cannot be stored or output to Excel. But it's still quite interesting.For example, my "base power" right now (no A/C, no pool pump, electric stove and oven off, etc.) appears to be about 2.1 kilowatts. That's right, the refrigerator plus the various "phantom loads" (Direct TV boxes, DVD players, PS3, televisions, clocks, etc.) are sucking electrical energy and turning it into heat and light and coldness at the rate of 2100 joules/second (2.1 kilowatts). Yikes! In a year, this will amount to over $2,000 just to have food cold and entertainment "ready to go." This needs some rethinking.
With the A/C and pool pump on in the daytime, we're looking at about 7.5 kilowatts. Wow! I've mentioned in a previous post that I estimate my family's use of energy to be equivalent to about 40 kilowatts. This includes vehicles, food, "stuff," electricity at home and work, etc. I had estimated my average continuous use of electrical energy in the house at about 2.8 kilowatts. Now, I'm not so sure. The pool pump goes year around (though not continuously - about six hours per day). Obviously the A/C doesn't but still, I think I may have underestimated.
I live in Anaheim, CA where electricity is provided by Anaheim Public Utilities at relatively reasonable rates and yet I must be spending at least $3,000/year on electricity. It's clearly time to start the same process for my house that I've engaged in with my car. This will certainly be a more difficult undertaking, but the payoff in savings and in CO2 reduction dictates that I undertake it forthwith. I could have gotten the information above by checking the meter and the bill, but like the ScanGauge II I use in my car, the Powerkuff makes it easy and fun to monitor home electrical energy use.
Update: A somewhat frustrating aspect of the Powerkuff is that one must remove the cover of the sensor with a screwdriver to change the three AA batteries. Further, the only way to turn the sensor off is to remove the batteries (or at least a battery). And if you monitor for extended periods, you will be doing a LOT of battery changing. Admittedly, there's a transformer and AC power input so that the unit can be plugged in. But I suspect that, like me, most people don't have an electrical outlet near their service panel.
One could go through a set of batteries every day at a cost of, say, $5. Needless to say, the Powerkuff won't help you save electricity at a rate such as to justify this. I tried using rechargeable batteries (1.2 V NiMH) but they're good for only a few hours, or even less.
The sensor unit needs a switch so that it can easily be turned on when information is being sought and turned off when attention isn't being paid. As I mentioned above, the data can't be stored anyway. Better still would be the ability to turn it off remotely, either from the display unit or the computer. Should I decide that the Powerkuff is something I need to keep, (which is up in the air due to this issue) I'll probably have the power supply wired into the unit from the service panel.
Sunday, July 12, 2009
The low hanging fruit
I've been driving to maximize fuel economy (minimize fuel consumption) and keeping detailed records of the effort for almost four years. I've been blogging about this and related topics for over three years. I've done all this while driving what would be considered "gas guzzlers." Some may scoff at such efforts, and the following is not meant to encourage people to trade in their fuel sippers for SUV's with big engines.
But I'm driving a vehicle (the Land Rover LR3 HSE) that is EPA estimated to achieve 16 m.p.g. combined. This is pretty close too, in the early days of driving it when I gave up on hypermiling attempts and drove it normally, that was about what I got. I now have a 10 tank and combined moving average of 21 m.p.g. A five m.p.g. difference, big deal, you say. Ah, but it is.
We discuss m.p.g., but the key here is g.p.m., the inverse. In a typical 10,000 mile year, at 16 m.p.g., a vehicle would use 625 gallons of fuel. At 21 m.p.g., it uses 476 gallons, 149 gallons less. If you're currently in a vehicle that gets 30 m.p.g., you'd have to drive in such a way as to achieve 54.2 m.p.g. to save a similar amount of fuel. And each of those saved gallons means about 19 pounds of carbon dioxide is not emitted.
If a driver can change his or her habits to increase mileage from 14 m.p.g. to 15 m.p.g., in a 10,000 mile year that driver will save approximately the same number of gallons as a driver who increases mileage from 25 m.p.g. to 28.4 m.p.g.
The point here is not to justify gas guzzlers, nor is it to pat myself on the back. Rather, it is to point out that there are an awful lot of gas guzzlers on the road, and they are the "low hanging fruit" for fuel savings. Unfortunately, few of the drivers of such vehicles share my craving for maximum fuel economy so the trick is in getting people on board this fruit truck.
And the same rationale that applies to individual drivers applies to car companies as well. Dramatically more fuel is saved if Ford improves the mileage of 20,000 pickup trucks from 14 m.p.g. to 17 m.p.g. than if they change the mileage of 20,000 compact cars from 32 m.p.g. to 35 m.p.g. I know that I'm not the first to come to this realization, but I think it receives far too little attention in the hypermiling and fuel economizing communities.
But I'm driving a vehicle (the Land Rover LR3 HSE) that is EPA estimated to achieve 16 m.p.g. combined. This is pretty close too, in the early days of driving it when I gave up on hypermiling attempts and drove it normally, that was about what I got. I now have a 10 tank and combined moving average of 21 m.p.g. A five m.p.g. difference, big deal, you say. Ah, but it is.
We discuss m.p.g., but the key here is g.p.m., the inverse. In a typical 10,000 mile year, at 16 m.p.g., a vehicle would use 625 gallons of fuel. At 21 m.p.g., it uses 476 gallons, 149 gallons less. If you're currently in a vehicle that gets 30 m.p.g., you'd have to drive in such a way as to achieve 54.2 m.p.g. to save a similar amount of fuel. And each of those saved gallons means about 19 pounds of carbon dioxide is not emitted.
If a driver can change his or her habits to increase mileage from 14 m.p.g. to 15 m.p.g., in a 10,000 mile year that driver will save approximately the same number of gallons as a driver who increases mileage from 25 m.p.g. to 28.4 m.p.g.
The point here is not to justify gas guzzlers, nor is it to pat myself on the back. Rather, it is to point out that there are an awful lot of gas guzzlers on the road, and they are the "low hanging fruit" for fuel savings. Unfortunately, few of the drivers of such vehicles share my craving for maximum fuel economy so the trick is in getting people on board this fruit truck.
And the same rationale that applies to individual drivers applies to car companies as well. Dramatically more fuel is saved if Ford improves the mileage of 20,000 pickup trucks from 14 m.p.g. to 17 m.p.g. than if they change the mileage of 20,000 compact cars from 32 m.p.g. to 35 m.p.g. I know that I'm not the first to come to this realization, but I think it receives far too little attention in the hypermiling and fuel economizing communities.
Friday, July 10, 2009
First order ordinary differential equations and the World Series of Poker
I play a fair amount of poker, both cash games and tournaments, both online and in "brick and mortar" casinos. Thus, of course, the World Series of Poker is of more than passing interest. That interest is shared by my CFO, and he sends me updates on the Main Event via im (internet messenger). He mentioned that, before tonight's dinner break, there were 1431 players left, and then mentioned later that there were 1071 (out of a starting field of 6494). And intuitively, the rate of elimination of players should be proportional to the number of players remaining. Sounds like a first order differential equation to me.
So, let p(t) be the number of players left at time t, then dp/dt=k*p(t) with k a negative constant. Now the time stamp from msm im for 1431 was at 18:54 PDT, and there were 1071 at 20:38 PDT. This is 104 minutes, but the dinner break is 90 minutes. This means that 360 eliminations took place in 14 minutes, absolutely not possible. This must mean that the updates are sporadic. I'll try a different method of finding two times with a known number of players and a known number of playing minutes between them. It looks like Level 13 ended with 945 players, and 90 minutes of play later, Level 14 ended with 810 players. Even this is sketchy, WSOP's own tournament update page has both 810 and 789 players as the current count. Oh well, I'm going with what I have.
Thus: dp(t)/dt-k*p(t)=0, p(0)=945, p(90)=810. This is a very simple problem and the solution is p(t)=945*exp(-0.0017127853*t). So, the tournament is won when p(t)=1, i.e., when one player is left. Now, this model has assumed that p(t) is a continuous function on the real numbers. At p(t)=945, this approximation may be reasonably accurate but when p(t) is, say, 3, it's clearly not. There are not going to be 3.43 or 2.71 players left. Nonetheless, solving the expression for t when p(t) =1 yields t of approximately 4000. That means after about 4000 more minutes of play, we should know a champion. That's about 67 hours and since they play something like 11 more days with 12 hours per day less breaks of about 3 hours, I'd guess there are actually about 100 hours left.
Various strategic considerations lead to certain times (particularly around getting "into the money" and getting to "the final table") when stalling and cautious play takes place.Thus, k, which I've assumed is a constant, is actually a function of p(t). That's a much more difficult problem though, and I'd only be guessing at the values of the relevant parameters. Possibly analyzing p(t) "piecewise" with k constant in each piece would do better. But the error is also partly attributable to the inaccurate reporting of players left at any given time. So predicting 67 hours is gratifyingly close. For a general idea, see the graph below.
This is, as the mathematically inclined will immediately see, a completely trivial problem. But for those who are not, it may be interesting to see the way a backslid mathematician looks at the world. For those whose interest is piqued by this exercise, I'd recommend "Towing Icebergs, Falling Dominoes, and Other Adventures in Applied Mathematics" by Robert B. Banks.
So, let p(t) be the number of players left at time t, then dp/dt=k*p(t) with k a negative constant. Now the time stamp from msm im for 1431 was at 18:54 PDT, and there were 1071 at 20:38 PDT. This is 104 minutes, but the dinner break is 90 minutes. This means that 360 eliminations took place in 14 minutes, absolutely not possible. This must mean that the updates are sporadic. I'll try a different method of finding two times with a known number of players and a known number of playing minutes between them. It looks like Level 13 ended with 945 players, and 90 minutes of play later, Level 14 ended with 810 players. Even this is sketchy, WSOP's own tournament update page has both 810 and 789 players as the current count. Oh well, I'm going with what I have.
Thus: dp(t)/dt-k*p(t)=0, p(0)=945, p(90)=810. This is a very simple problem and the solution is p(t)=945*exp(-0.0017127853*t). So, the tournament is won when p(t)=1, i.e., when one player is left. Now, this model has assumed that p(t) is a continuous function on the real numbers. At p(t)=945, this approximation may be reasonably accurate but when p(t) is, say, 3, it's clearly not. There are not going to be 3.43 or 2.71 players left. Nonetheless, solving the expression for t when p(t) =1 yields t of approximately 4000. That means after about 4000 more minutes of play, we should know a champion. That's about 67 hours and since they play something like 11 more days with 12 hours per day less breaks of about 3 hours, I'd guess there are actually about 100 hours left.
Various strategic considerations lead to certain times (particularly around getting "into the money" and getting to "the final table") when stalling and cautious play takes place.Thus, k, which I've assumed is a constant, is actually a function of p(t). That's a much more difficult problem though, and I'd only be guessing at the values of the relevant parameters. Possibly analyzing p(t) "piecewise" with k constant in each piece would do better. But the error is also partly attributable to the inaccurate reporting of players left at any given time. So predicting 67 hours is gratifyingly close. For a general idea, see the graph below.
This is, as the mathematically inclined will immediately see, a completely trivial problem. But for those who are not, it may be interesting to see the way a backslid mathematician looks at the world. For those whose interest is piqued by this exercise, I'd recommend "Towing Icebergs, Falling Dominoes, and Other Adventures in Applied Mathematics" by Robert B. Banks.
Wednesday, July 08, 2009
GGBFS - will it save the world?
Concrete is a ubiquitous construction material, from ancient times through today. The primary expenditure of energy in concrete production is in the manufacture of cement (the gray powdery substance that binds the aggregates together after addition of water). And, as mentioned in an earlier post, with respect to CO2 emissions, its impacts extend beyond the emissions from the heat necessary to produce it since turning limestone, CaCO3, into lime, CaO, releases CO2. It's estimated that, worldwide, cement production is responsible for about 5% of CO2 emissions, and that on the order of a ton of CO2 is released in the production of a ton of cement.
It's difficult to conceive of a replacement for concrete, so efforts to mitigate the impact of concrete construction on CO2 emissions revolve around replacement of the most CO2 intensive components of the cement. As mentioned in the article linked above, one possibility is "Eco-Cement" which uses magnesium carbonate instead of calcium carbonate (limestone) to produce cement. The topic of this post is the partial replacement of cement with ground granulated blast furnace slag ("GGBFS").
GGBFS is a by-product of producing iron from ore or from producing certain types of steel. The slag typically consists of silicates, aluminosilicates, and calcium-alumina-silicates. The molten slag can be cooled slowly or quickly, but must be quenched (cooled very quickly) to prevent the formation of crystals. The slag must be "vitreous" (glassy) in order to have cementitious properties. The vitreous, granulated slag is then ground to an extremely fine powder for use as a substitute for portland cement in proportions as high as 70% in concrete.
The concrete produced using GGBFS has many desirable characteristics, including increased strength, increased density, decreased permeability and (arguably) increased resistance to sulfate attack and the dreaded alkali silica reaction. Its only significant drawbacks are increased setting time and lower early strength. These can be mitigated where necessary by the addition of appropriate admixtures. Further, the slow setting and strength gain is at least partially due to the relative large (compared to portland cement) grain size using current economically feasible technology. As grinding technology improves, this limitation will diminish. And slow setting is sometimes an advantage, for example, when long transit routes are necessary or during hot weather concreting. That slow setting is sometimes a benefit is demonstrated by the fact that there are currently marketed set retarding admixtures.
This use of what has, in the past, been a waste product of iron and steel production for an environmentally and structurally beneficial application seems to be a win for all concerned. But can it save the world? I wouldn't go that far. When utilized in concrete with equal portions of portland cement and GGBFS, the overall CO2 emission can be roughly halved. This is accomplished by both a reduced need for heating energy and by a reduction in the amount of limestone to be calcined for a given amount of cement.
So what's the potential? Using very rough figures, about 320 million metric tons of slag of suitable chemistry are produced worldwide each year. Some of this is used for other purposes, but we'll use that amount to set a cap on the replacement possible. Approximately 2.5 billion metric tons of cement are produced annually, and roughly 0.8 tons of CO2 emission are avoided for each ton of GGBFS utilized in place of portland cement. Obviously, plenty of capacity is available to use of all the slag produced if this could actually be accomplished. This would result in reduction in CO2 emissions of about 250 million metric tons or, roughly, 1% of world CO2 emissions. It won't save the world but with the G8 agreeing today to reduce emissions 80% by 2050, we have to start somewhere.
It's difficult to conceive of a replacement for concrete, so efforts to mitigate the impact of concrete construction on CO2 emissions revolve around replacement of the most CO2 intensive components of the cement. As mentioned in the article linked above, one possibility is "Eco-Cement" which uses magnesium carbonate instead of calcium carbonate (limestone) to produce cement. The topic of this post is the partial replacement of cement with ground granulated blast furnace slag ("GGBFS").
GGBFS is a by-product of producing iron from ore or from producing certain types of steel. The slag typically consists of silicates, aluminosilicates, and calcium-alumina-silicates. The molten slag can be cooled slowly or quickly, but must be quenched (cooled very quickly) to prevent the formation of crystals. The slag must be "vitreous" (glassy) in order to have cementitious properties. The vitreous, granulated slag is then ground to an extremely fine powder for use as a substitute for portland cement in proportions as high as 70% in concrete.
The concrete produced using GGBFS has many desirable characteristics, including increased strength, increased density, decreased permeability and (arguably) increased resistance to sulfate attack and the dreaded alkali silica reaction. Its only significant drawbacks are increased setting time and lower early strength. These can be mitigated where necessary by the addition of appropriate admixtures. Further, the slow setting and strength gain is at least partially due to the relative large (compared to portland cement) grain size using current economically feasible technology. As grinding technology improves, this limitation will diminish. And slow setting is sometimes an advantage, for example, when long transit routes are necessary or during hot weather concreting. That slow setting is sometimes a benefit is demonstrated by the fact that there are currently marketed set retarding admixtures.
This use of what has, in the past, been a waste product of iron and steel production for an environmentally and structurally beneficial application seems to be a win for all concerned. But can it save the world? I wouldn't go that far. When utilized in concrete with equal portions of portland cement and GGBFS, the overall CO2 emission can be roughly halved. This is accomplished by both a reduced need for heating energy and by a reduction in the amount of limestone to be calcined for a given amount of cement.
So what's the potential? Using very rough figures, about 320 million metric tons of slag of suitable chemistry are produced worldwide each year. Some of this is used for other purposes, but we'll use that amount to set a cap on the replacement possible. Approximately 2.5 billion metric tons of cement are produced annually, and roughly 0.8 tons of CO2 emission are avoided for each ton of GGBFS utilized in place of portland cement. Obviously, plenty of capacity is available to use of all the slag produced if this could actually be accomplished. This would result in reduction in CO2 emissions of about 250 million metric tons or, roughly, 1% of world CO2 emissions. It won't save the world but with the G8 agreeing today to reduce emissions 80% by 2050, we have to start somewhere.
Sunday, July 05, 2009
Solar hot water
Would an American building owner tolerate a roof line such as that seen here? Could an American architect stomach such an appearance? Doubtful. These are evacuated tube solar water heaters as seen on rooftops throughout the cities we visited in China. China is encouraging the use of this technology and the results are visually apparent. But are the energy savings (and consequent emissions reductions) significant?A report by the National Renewable Energy Laboratory (NREL) concludes that solar thermal water heating has the technical potential to save about one "quad" (quadrillion, or 10^15, btu) of primary energy per year, or right at 1% of our primary energy consumption. This would result in the avoidance of the emission of between 50 and 75 million metric tons of carbon dioxide and potentially save on the order of $8 billion per year in energy expenditures. The report is dated April of 2007, so the financial considerations are likely more compelling now, with rising primary energy costs. It would seem as if China were on the right track.
The evacuated tube technology is capable of delivering hot water even when skies are cloudy and temperatures are cool. In fact, they can operate in ambient temperatures below freezing. So, are there downsides? Not many, the primary negative is the payback period. For reasons I can't clearly explain, the Chinese systems typically cost on the order of 4,500 yuan, or about $660. In the U.S. similar systems cost more like $5,000 installed. This is a major disincentive, though beneficial tax treatment may reduce the cost in some areas. And although some think they're ugly (and my %&*^%^#@^ homeowners' association would scream bloody murder), I think they're lovely.
Saturday, July 04, 2009
Chinese "vehicle" traffic
While in China, we motored around on well paved roads (except for a visit to a farming village - more on that in another post) in air conditioned buses and flew from city to city on the best of Boeing's and Airbus' stable. And we were by no means alone as the only modern vehicle on China's highways. But there were a vast number of two and three wheeled vehicles, and both kinds came in motorized (internal combustion engine, electric motors) and human powered. And among the three wheeled vehicles, there was everything from large trucks hauling cargo to pedal powered carts hauling huge amounts of grain, water, children, etc. In all, it was an incredible mix of vehicle types and uses, far far beyond anything one would see in the United States.
We saw lots of these enclosed "taxis" on a three wheeled motorcycle base. Few were as pristine as this one, outside of the Forbidden City, but they were plentiful. I don't know what kind of mileage they might get, but I will hazard a guess of 40 m.p.g., based on what I've heard about various motorcycles. Certainly, that's better than an automobile taxi would get.
Then there were people doing goods transportation with muscle power. The example shown here is fairly extreme but not uniquely so. China is still a developing country and has many of the characteristics of such a status. But it's developing fast.
As I mentioned above, there were also full-size vehicles of types not seen in the U.S., both for personal transportation and for moving cargo. I haven't yet determined the benefit of the three wheeled configuration, any suggestions?
The alternative vehicles I've contemplated in this blog (here, here, and here), i.e., electric scooters, are extremely popular in China. There is some controversy over their use and the gas powered scooter purveyors, car manufacturers, etc. want them banned, but they certainly appear to have reached critical mass in China.
It's easy to tell that this is not a photograph of a U.S. street. And I'm not so sure we're doing a better job, the vehicle sizes and weights are much more appropriate to the loads they carry. As I've mentioned, my 6000 pound Land Rover LR3 HSE is a heck of a lot of metal to carry around a 185 pound man. Unfortunately, the Chinese appear to aspire to our situation rather than the reverse.
Finally, these vehicles, of which we saw many in Kunming, caused me the greatest amount of head scratching. Can it really be efficient to have a belt driven vehicle with an exposed engine? But, given the number of these that were on the road, there's undoubtedly a sound economic reason for their use. Any ideas?
We saw lots of these enclosed "taxis" on a three wheeled motorcycle base. Few were as pristine as this one, outside of the Forbidden City, but they were plentiful. I don't know what kind of mileage they might get, but I will hazard a guess of 40 m.p.g., based on what I've heard about various motorcycles. Certainly, that's better than an automobile taxi would get.
Then there were people doing goods transportation with muscle power. The example shown here is fairly extreme but not uniquely so. China is still a developing country and has many of the characteristics of such a status. But it's developing fast.
As I mentioned above, there were also full-size vehicles of types not seen in the U.S., both for personal transportation and for moving cargo. I haven't yet determined the benefit of the three wheeled configuration, any suggestions?
The alternative vehicles I've contemplated in this blog (here, here, and here), i.e., electric scooters, are extremely popular in China. There is some controversy over their use and the gas powered scooter purveyors, car manufacturers, etc. want them banned, but they certainly appear to have reached critical mass in China.
It's easy to tell that this is not a photograph of a U.S. street. And I'm not so sure we're doing a better job, the vehicle sizes and weights are much more appropriate to the loads they carry. As I've mentioned, my 6000 pound Land Rover LR3 HSE is a heck of a lot of metal to carry around a 185 pound man. Unfortunately, the Chinese appear to aspire to our situation rather than the reverse.
Finally, these vehicles, of which we saw many in Kunming, caused me the greatest amount of head scratching. Can it really be efficient to have a belt driven vehicle with an exposed engine? But, given the number of these that were on the road, there's undoubtedly a sound economic reason for their use. Any ideas?
Friday, July 03, 2009
Energy use in construction in China
I've been fortunate enough to have spent almost two weeks in China. I spent four days in Beijing, four days in Xi' An, three in Kunming, and most of a day in Guangzhou. I was there as part of a People to People Citizen Ambassador Program with a Public Works delegation. As such, the concentration during the professional meetings revolved around public works and we met with highway and traffic engineering groups, wastewater treatment facilities managers and engineers, and "underground" (known in the U.S. as subway) engineers.
We also had several cultural opportunities and were fortunate enough to visit many of the premier Chinese cultural sites, such as Tian An Men Square, the Forbidden City, the Great Wall, and the Terracotta Warriors. I felt privileged to visit these amazing sites, but the most compelling memories I'll keep are related to the openness of the people. We talked about politics, about Chairman Mao (60% good, 40% bad according to one of the people I spoke with in depth), the Cultural Revolution, local, regional, national, and global politics. I believe I got at least a rudimentary understanding of how the Chinese people (though certainly not the Government) feel about their place in the world, both historically and currently.
But one of the very most stunning things was the construction activity in China. In every city we visited, there were literally hundreds of tower cranes erecting massive structures. The vast majority of the structures were concrete, and I got curious about the consequent energy usage and greenhouse gas emissions. Per Wikipedia (and consequently unarguably) it takes anywhere from three to six gigajoules of energy to produce a tonne of cement. I think, based on my observations, that China would be at the high end of this range, so I'll go with six. This is is about 2.72*10^6 joules per pound. A sack of cement contains 94 pounds, and a garden variety concrete mix might use about 6.7 sacks of cement per cubic yard. So, just the cement in a cubic yard of concrete requires 6.7*94*2.72*10^6 or 1.71*10^9 joules of energy to produce. This is the total heat energy available in about 14 gallons of gasoline. It takes no account of the aggregate, the sand, the water, and the admixtures, nor of the other construction materials utilized.
Further, the production of cement is a "double whammy" with respect to carbon dioxide emissions. Not only is it extremely energy intensive, but the fundamental process of cement production is to "calcine" limestone, that is, to take limestone (calcium carbonate, CaCO3) and use heat to turn this limestone to lime (CaO), releasing CO2 in the process. One of the goals of my China adventure is to find a way to work with the Chinese to produce cementitious materials with a reduced cement content and thus reduce the CO2 impact of concrete construction.
In any case, the graphic above (courtesy of Prof. Goose at The Oil Drum) shows Chinese cement production in 2007 at 1.3*10^9 metric tonnes (1.3 "gigatonnes"). Using the energy input estimate from above, this would involve about 7.8*10^18 joules. This amount of energy in a year is an average power (easily found using WolframAlpha) of 2.47*10^11 watts.
This is a staggering rate of energy use. Typing "7.8*10^18 joules/year in watts" into WolframAlpha yields not only the above number for power but shows that this about 1.9% of the rate of global power consumption. And this is just to make cement, not the power required from limestone quarrying through placing concrete into a structure, let alone all of the other components comprising a completed structure.
Using a variety of approximations and estimates for the amount of "space" this quantity of cement could be used to produce, and the embedded energy in building construction (see here), I estimate that overall energy use in concrete framed construction in China in 2007 was on the order of 3.8*10^19 joules. This is getting to be a very significant portion of world energy usage, on the order of 9%. It's also over 40% of China's total energy usage. This would seem to be the real "Great Leap Forward," but how long can it last?
We also had several cultural opportunities and were fortunate enough to visit many of the premier Chinese cultural sites, such as Tian An Men Square, the Forbidden City, the Great Wall, and the Terracotta Warriors. I felt privileged to visit these amazing sites, but the most compelling memories I'll keep are related to the openness of the people. We talked about politics, about Chairman Mao (60% good, 40% bad according to one of the people I spoke with in depth), the Cultural Revolution, local, regional, national, and global politics. I believe I got at least a rudimentary understanding of how the Chinese people (though certainly not the Government) feel about their place in the world, both historically and currently.
But one of the very most stunning things was the construction activity in China. In every city we visited, there were literally hundreds of tower cranes erecting massive structures. The vast majority of the structures were concrete, and I got curious about the consequent energy usage and greenhouse gas emissions. Per Wikipedia (and consequently unarguably) it takes anywhere from three to six gigajoules of energy to produce a tonne of cement. I think, based on my observations, that China would be at the high end of this range, so I'll go with six. This is is about 2.72*10^6 joules per pound. A sack of cement contains 94 pounds, and a garden variety concrete mix might use about 6.7 sacks of cement per cubic yard. So, just the cement in a cubic yard of concrete requires 6.7*94*2.72*10^6 or 1.71*10^9 joules of energy to produce. This is the total heat energy available in about 14 gallons of gasoline. It takes no account of the aggregate, the sand, the water, and the admixtures, nor of the other construction materials utilized.Further, the production of cement is a "double whammy" with respect to carbon dioxide emissions. Not only is it extremely energy intensive, but the fundamental process of cement production is to "calcine" limestone, that is, to take limestone (calcium carbonate, CaCO3) and use heat to turn this limestone to lime (CaO), releasing CO2 in the process. One of the goals of my China adventure is to find a way to work with the Chinese to produce cementitious materials with a reduced cement content and thus reduce the CO2 impact of concrete construction.
In any case, the graphic above (courtesy of Prof. Goose at The Oil Drum) shows Chinese cement production in 2007 at 1.3*10^9 metric tonnes (1.3 "gigatonnes"). Using the energy input estimate from above, this would involve about 7.8*10^18 joules. This amount of energy in a year is an average power (easily found using WolframAlpha) of 2.47*10^11 watts.This is a staggering rate of energy use. Typing "7.8*10^18 joules/year in watts" into WolframAlpha yields not only the above number for power but shows that this about 1.9% of the rate of global power consumption. And this is just to make cement, not the power required from limestone quarrying through placing concrete into a structure, let alone all of the other components comprising a completed structure.
Using a variety of approximations and estimates for the amount of "space" this quantity of cement could be used to produce, and the embedded energy in building construction (see here), I estimate that overall energy use in concrete framed construction in China in 2007 was on the order of 3.8*10^19 joules. This is getting to be a very significant portion of world energy usage, on the order of 9%. It's also over 40% of China's total energy usage. This would seem to be the real "Great Leap Forward," but how long can it last?
Wednesday, June 10, 2009
The nature of blogging
I've had the good fortune to be cited at Swans on Tea and to be included in the blog roll at Dot Physics. This has been gratifying, we all want to be heard when we step onto our soapbox. However, it's caused me to wonder what's really going on when we blog.
Naturally, I've gone to other blogs on the blog rolls of each of those sites, and on to others from those. This is what "web surfing" was about back when I first got involved with the internet in 1995 (holy crap, by the way). Several times, through circuitous routes, I wound up coming to various blogs from different directions. Thus, one might speculate that I would find myself in general agreement with the editorial viewpoint of such blogs. After all, I got there, in a sense, from my own. Is this true and does it matter?
The answers are "not necessarily" and "I think so." For example, I wound up on a site called Pharyngula, published by a biologist named PZ Myers. It is a stridently atheistic site. Now, at various times in my life I've been militantly atheistic, I've been a Christian believer, and I've been agnostic. I'm currently in "searching" mode and find much of value in the essays of Professor Steven Dutch's "Science, Pseudoscience, and Irrationalism" pages. Dr. Dutch, a professor in the Earth Sciences department at the University of Wisconsin Green Bay, is relentlessly rational and no one that I've read does a better job of demolishing all manner of pseudoscience. And yet, he is a person of faith.
The Pharyngula blog is one of many at a site called ScienceBlogs. Another is the Denialism Blog which discusses a variety of pseudoscientific and crank ideas. Typical targets are Intelligent Design proponents, global warming denialists, Holocaust denialists, 9/11 conspiracy theorists, etc. Sometimes they may point out the logical fallacies present in the arguments of the denialists, other times they may delve into their psychology. I find myself generally aligned with the viewpoints presented. But not always and not completely.
After a comment I added to a post in Pharyngula I found myself characterized as an idiot, an absolute lunatic, a troll, a slimy troll, and a dipshit (though the person who called me the last weakly retracted it), and was told to "fuck off." Then, not surprisingly, when I did so I was accused of "stomping off in a huff." What was my offense? Well, the post topic was a video featuring Bill Donohue being quite belligerent toward a victim of sexual abuse by the Catholic clergy.
Now, I found Donohue's behavior reprehensible and never said otherwise. But I did feel, reading the comments, an air of smug superiority in the commenters with the flavor of "this kind of thing would never happen but for the unenlightened, superstitious, theistic thinking of the Catholic Church." I concede that I chose a confrontational way of making this point, to wit, I wrote:
"The context of this post and of the video is implying something to the effect that 'theistic thinking increases the likelihood of sexual and physical abuse of minors.'
So, then, may I assume, based on Stalin's Soviet Union, that 'atheistic thinking increases the likelihood of mass murder?'"
My point was that evil is evil and those who engage in it will use whatever is their (or the prevailing) ideology to justify such behavior, should such justification be necessary.
I would not have chosen such an incendiary entry into the discussion but the air of self-righteous chest thumping (interspersed with various suggestions of physical abuse and torture to be inflicted upon Mr. Donohue, quoting one of Myers' favorite phrases, "I kid you not") of some (not all) of the participants was quite off-putting. And yet, I undoubtedly have much in common with many of the contributors. The blogosphere, like politics, makes strange bedfellows.
Naturally, I've gone to other blogs on the blog rolls of each of those sites, and on to others from those. This is what "web surfing" was about back when I first got involved with the internet in 1995 (holy crap, by the way). Several times, through circuitous routes, I wound up coming to various blogs from different directions. Thus, one might speculate that I would find myself in general agreement with the editorial viewpoint of such blogs. After all, I got there, in a sense, from my own. Is this true and does it matter?
The answers are "not necessarily" and "I think so." For example, I wound up on a site called Pharyngula, published by a biologist named PZ Myers. It is a stridently atheistic site. Now, at various times in my life I've been militantly atheistic, I've been a Christian believer, and I've been agnostic. I'm currently in "searching" mode and find much of value in the essays of Professor Steven Dutch's "Science, Pseudoscience, and Irrationalism" pages. Dr. Dutch, a professor in the Earth Sciences department at the University of Wisconsin Green Bay, is relentlessly rational and no one that I've read does a better job of demolishing all manner of pseudoscience. And yet, he is a person of faith.
The Pharyngula blog is one of many at a site called ScienceBlogs. Another is the Denialism Blog which discusses a variety of pseudoscientific and crank ideas. Typical targets are Intelligent Design proponents, global warming denialists, Holocaust denialists, 9/11 conspiracy theorists, etc. Sometimes they may point out the logical fallacies present in the arguments of the denialists, other times they may delve into their psychology. I find myself generally aligned with the viewpoints presented. But not always and not completely.
After a comment I added to a post in Pharyngula I found myself characterized as an idiot, an absolute lunatic, a troll, a slimy troll, and a dipshit (though the person who called me the last weakly retracted it), and was told to "fuck off." Then, not surprisingly, when I did so I was accused of "stomping off in a huff." What was my offense? Well, the post topic was a video featuring Bill Donohue being quite belligerent toward a victim of sexual abuse by the Catholic clergy.
Now, I found Donohue's behavior reprehensible and never said otherwise. But I did feel, reading the comments, an air of smug superiority in the commenters with the flavor of "this kind of thing would never happen but for the unenlightened, superstitious, theistic thinking of the Catholic Church." I concede that I chose a confrontational way of making this point, to wit, I wrote:
"The context of this post and of the video is implying something to the effect that 'theistic thinking increases the likelihood of sexual and physical abuse of minors.'
So, then, may I assume, based on Stalin's Soviet Union, that 'atheistic thinking increases the likelihood of mass murder?'"
My point was that evil is evil and those who engage in it will use whatever is their (or the prevailing) ideology to justify such behavior, should such justification be necessary.
I would not have chosen such an incendiary entry into the discussion but the air of self-righteous chest thumping (interspersed with various suggestions of physical abuse and torture to be inflicted upon Mr. Donohue, quoting one of Myers' favorite phrases, "I kid you not") of some (not all) of the participants was quite off-putting. And yet, I undoubtedly have much in common with many of the contributors. The blogosphere, like politics, makes strange bedfellows.
Saturday, June 06, 2009
The amazing 110 m.p.g. Mustang
Doug Pelmear of HP2g and something called HorsepowerSales.net has made a lot of claims for his engine development. He claims to have developed a "rod and piston" engine capable of developing 400 horsepower and 500 foot pounds of torque. It's also, per Pelmear, capable of 110 m.p.g. equivalent. It's "equivalent" because the engine uses E85 fuel, 85% ethanol and 15% gasoline.
Pelmear had touted his entry into the Progressive Automotive X Prize competition, whose organizers will distribute a $10M prize pool for teams that produce commercially viable vehicles capable of achieving a sustained fuel economy of 100 MPGe (m.p.g. equivalent). Pelmear's HP2g entry was to have been a 1987 Mustang with his proprietary engine installed. However, a press release dated June 4, 2009 states that the HP2g Mustang has been withdrawn from the competition despite several videos (see here and here for example) showing Pelmear expressing his confidence that he'd win the prize. Various reasons are given for the withdrawal, I have no data regarding the legitimacy of the rationale, so I'll just take it at face value.
There are several articles on the HP2g web site announcing the opening, on June 1, 2009 of an engine R & D and manufacturing plant. There's also news of an agreement between HP2g and "Revenge Designs" to install the engines in the "Revenge Verde," a super car of some sort. I can't find a lot of detail about the Revenge Verde, but a rendering is at left.
Little information about the actual technology being employed is available on HP2g's web site or in any of the recorded interviews at the various media events Pelmear has attended. He's referred to technology originated during World War 2 by his grandfather and to extensive electronics. There are a couple of vague references to "more precise manufacturing techniques" and "tighter tolerances." In all the videos, the hood of the car is closed and in most the Mustang is sitting still. In the ones where it's moving, it's driving in a very normal fashion, no 400 h.p. tire smoking burnouts. Though his site has a "table of fill ups and miles driven", no independent authentication is given or even implied.
Skepticism is rampant on the Ecomodder Blog about the Mustang, as might be inferred from the title of the article ("runs on hot air and cattle manure" for those not wanting to click on or mouse over the link). I actually commented there and didn't find it to be utterly, completely, totally impossible for Pelmear's claims to be true. But his site includes a section entitled "Test Data" that should enable me to get a more precise estimate as to the plausibility of his claims.
The relevant data is as follows (and compliments to Pelmear and HP2g for publishing them, though the pertinent ones are really just stock Mustang numbers):
Pelmear had touted his entry into the Progressive Automotive X Prize competition, whose organizers will distribute a $10M prize pool for teams that produce commercially viable vehicles capable of achieving a sustained fuel economy of 100 MPGe (m.p.g. equivalent). Pelmear's HP2g entry was to have been a 1987 Mustang with his proprietary engine installed. However, a press release dated June 4, 2009 states that the HP2g Mustang has been withdrawn from the competition despite several videos (see here and here for example) showing Pelmear expressing his confidence that he'd win the prize. Various reasons are given for the withdrawal, I have no data regarding the legitimacy of the rationale, so I'll just take it at face value.
There are several articles on the HP2g web site announcing the opening, on June 1, 2009 of an engine R & D and manufacturing plant. There's also news of an agreement between HP2g and "Revenge Designs" to install the engines in the "Revenge Verde," a super car of some sort. I can't find a lot of detail about the Revenge Verde, but a rendering is at left.Little information about the actual technology being employed is available on HP2g's web site or in any of the recorded interviews at the various media events Pelmear has attended. He's referred to technology originated during World War 2 by his grandfather and to extensive electronics. There are a couple of vague references to "more precise manufacturing techniques" and "tighter tolerances." In all the videos, the hood of the car is closed and in most the Mustang is sitting still. In the ones where it's moving, it's driving in a very normal fashion, no 400 h.p. tire smoking burnouts. Though his site has a "table of fill ups and miles driven", no independent authentication is given or even implied.
Skepticism is rampant on the Ecomodder Blog about the Mustang, as might be inferred from the title of the article ("runs on hot air and cattle manure" for those not wanting to click on or mouse over the link). I actually commented there and didn't find it to be utterly, completely, totally impossible for Pelmear's claims to be true. But his site includes a section entitled "Test Data" that should enable me to get a more precise estimate as to the plausibility of his claims.
The relevant data is as follows (and compliments to Pelmear and HP2g for publishing them, though the pertinent ones are really just stock Mustang numbers):
- Cd (Coefficient of Drag): 0.42
- Frontal Area: 22 ft^2 (2.044 m^2)
- Curb weight: 3250 pounds (curb mass of 1474 kg)
We'll add the following: two 75 kilogram passengers; tires with coefficient of rolling resistance of 0.010 (this is relatively low, but what the heck).
So what does that mean at 55 m.p.h., or 24.59 m/s? Ignoring the energy in the rotating masses and using the methodology I've illustrated many times in the course of this blog, I'd estimate that about 470 newtons would propel this Mustang down the highway at a steady speed on level ground with no wind. As I've frequently mentioned, force times speed is power (assuming that the force is directed parallel to the velocity so that vector calculations aren't required) so 470 newtons at 24.59 m/s requires 11.56 kilowatts or 15.51 horsepower.
Moving on, E85 fuel should have a heat of combustion (that is, energy converted through burning) of 8.653*10^7 j/gal (joules/gallon). I will assume "110 MPGe" means that if E85 had the same specific energy (energy per unit volume) as gasoline, the vehicle would travel 110 miles on a gallon of it. So I'll multiply 110 miles by the ratio of the energy content of E85 to that of gasoline, or 8.653*10^7/1.225*10^8 and speculate that Pelmear is claiming about 77.7 miles out of a gallon of E85. Equivalently, Pelmear would be burning 1/77.7 or 0.01287 gallons of E85 per mile. In that fraction of a gallon, there are 1.1136*10^6 joules of thermal energy available through combustion.
We'll ignore the fuel needed to add the kinetic energy required to get the vehicle to 55 m.p.h. and the various rotating masses in motion and just look at the energy required to maintain 55 m.p.h. with conditions as detailed above. A mile is 1609 meters, so exerting a force of 470 newtons over that distance requires doing work of 756,700 joules. These joules come from burning the E85 so Pelmear is claiming an efficiency of at least (remember we ignored adding kinetic energy, hills, wind, etc.) of 7.567*10^5/1.1136*10^6 or 68%.
This would be above the maximum theoretical thermodynamic efficiency possible with an Otto cycle engine. Even granting that E85 has a significantly higher octane rating than any straight gasoline and thus allows much higher compression ratios to be used and assuming Pelmear has increased his compression ratio to 15:1 (which would require much more massive components than those in a stock gasoline engine), the maximum theoretical efficiency would be about 66%. This assumes no friction in the engine, no throttling or pumping losses, no energy to accessories, etc.
Note that I've given Pelmear the benefit of the doubt at every turn. The most generous assumption I've made is to run the calculations at 55 m.p.h. His site references speeds of 70 m.p.h. where much more energy would be required. And any variance from the idealized conditions hypothesized would reduce the fuel efficiency. I'm sorry, but unless someone points out an error in my calculations or data, I'm calling shenanigans.
Update: I've looked at more of the figures from HP2g's site for fill ups and mileage. They are showing numbers as high as 136.85 m.p.g. (actual miles divided by actual U.S. gallons, MPGe would be much higher). This would mean that the HP2g Mustang was getting significantly more than 100% of the energy available in the E85.
Update 2: A series of email correspondences with HP2g is shown below. Make of them what you will (start at the bottom and work up). Note that the engine "does not necessarily defy the laws of physics" (italics mine).
Update 3: Progressive Insurance Automotive X PRIZE Responds to HP2g Claims
Update 4: In this video the interviewer (from CNN) states that developers think that with a little more tweaking they'll get 500 miles per gallon.
Edison had naysayers too, I'm glad he continued on... Please refrain from contacting us again. First/Last warning.
-----Original Message----- From: Rob
Sent: Monday, June 8, 2009 02:34 PM
To:
Subject: RE: Your claims
Good morning,
No technologies enable more energy to be derived from fuel than is available in the fuel to begin with. Certainly there are thermodynamic cycles other than the Otto cycle, but none of them allow the conversion of more chemical energy to kinetic energy and work than are available in the chemical energy to begin with. Mileage figures such as 136.85 m.p.g. with the drag area of a Mustang and the rolling resistance of any tires currently available would exceed that amount by a considerable margin. There are a variety of reasons why such a claim would be made, but getting more energy out than is in the fuel is not one of them. Pending further information, it's very difficult for me to find such claims plausible. If you can supply such information, fine. If not, I guess time will tell.
Thanks,
Rob
From:
Sent: Monday, June 08, 2009 11:00 AM
To: Rob
Subject: Re: Your claims
Hello, Rob: The HP2g not only has been EPA tested, but its fuel economy has been ested in over 8,000 miles of driving in cities, towns, interstates, desserts, mountains and speed tests. The HP2g’s technologies are not those that you know and are familiar with. The engine does not necessarily defy the laws of physics just our prior understanding of how engines are supposed to work. When we are authorized to release the EPA info we will. It is in our possession. Thank you,
Team HP2g
-----Original Message----- From: Rob
Sent: Monday, June 8, 2009 12:17 AM
To:
Subject: RE: Your claims
Can you provide documentation? It’s very difficult to defy the laws of physics.
Rob
From:
Sent: Sunday, June 07, 2009 9:11 PM
To: Rob
Subject: Re: Your claims
EPA tested.
-----Original Message----- From: Rob
Sent: Sunday, June 7, 2009 10:36 PM
To:
Subject: Your claims
I’m afraid that very straightforward calculations show that your claims, as stated, cannot be correct. I wish that they were.
The calculations are at http://hamiltonianfunction.blogspot.com/2009/06/amazing-110-mpg-mustang_06.html.
If there are errors there, I’m sure you’ll point them out.
Rob
So what does that mean at 55 m.p.h., or 24.59 m/s? Ignoring the energy in the rotating masses and using the methodology I've illustrated many times in the course of this blog, I'd estimate that about 470 newtons would propel this Mustang down the highway at a steady speed on level ground with no wind. As I've frequently mentioned, force times speed is power (assuming that the force is directed parallel to the velocity so that vector calculations aren't required) so 470 newtons at 24.59 m/s requires 11.56 kilowatts or 15.51 horsepower.
Moving on, E85 fuel should have a heat of combustion (that is, energy converted through burning) of 8.653*10^7 j/gal (joules/gallon). I will assume "110 MPGe" means that if E85 had the same specific energy (energy per unit volume) as gasoline, the vehicle would travel 110 miles on a gallon of it. So I'll multiply 110 miles by the ratio of the energy content of E85 to that of gasoline, or 8.653*10^7/1.225*10^8 and speculate that Pelmear is claiming about 77.7 miles out of a gallon of E85. Equivalently, Pelmear would be burning 1/77.7 or 0.01287 gallons of E85 per mile. In that fraction of a gallon, there are 1.1136*10^6 joules of thermal energy available through combustion.
We'll ignore the fuel needed to add the kinetic energy required to get the vehicle to 55 m.p.h. and the various rotating masses in motion and just look at the energy required to maintain 55 m.p.h. with conditions as detailed above. A mile is 1609 meters, so exerting a force of 470 newtons over that distance requires doing work of 756,700 joules. These joules come from burning the E85 so Pelmear is claiming an efficiency of at least (remember we ignored adding kinetic energy, hills, wind, etc.) of 7.567*10^5/1.1136*10^6 or 68%.
This would be above the maximum theoretical thermodynamic efficiency possible with an Otto cycle engine. Even granting that E85 has a significantly higher octane rating than any straight gasoline and thus allows much higher compression ratios to be used and assuming Pelmear has increased his compression ratio to 15:1 (which would require much more massive components than those in a stock gasoline engine), the maximum theoretical efficiency would be about 66%. This assumes no friction in the engine, no throttling or pumping losses, no energy to accessories, etc.
Note that I've given Pelmear the benefit of the doubt at every turn. The most generous assumption I've made is to run the calculations at 55 m.p.h. His site references speeds of 70 m.p.h. where much more energy would be required. And any variance from the idealized conditions hypothesized would reduce the fuel efficiency. I'm sorry, but unless someone points out an error in my calculations or data, I'm calling shenanigans.
Update: I've looked at more of the figures from HP2g's site for fill ups and mileage. They are showing numbers as high as 136.85 m.p.g. (actual miles divided by actual U.S. gallons, MPGe would be much higher). This would mean that the HP2g Mustang was getting significantly more than 100% of the energy available in the E85.
Update 2: A series of email correspondences with HP2g is shown below. Make of them what you will (start at the bottom and work up). Note that the engine "does not necessarily defy the laws of physics" (italics mine).
Update 3: Progressive Insurance Automotive X PRIZE Responds to HP2g Claims
Update 4: In this video the interviewer (from CNN) states that developers think that with a little more tweaking they'll get 500 miles per gallon.
Edison had naysayers too, I'm glad he continued on... Please refrain from contacting us again. First/Last warning.
-----Original Message----- From: Rob
Sent: Monday, June 8, 2009 02:34 PM
To:
Subject: RE: Your claims
Good morning,
No technologies enable more energy to be derived from fuel than is available in the fuel to begin with. Certainly there are thermodynamic cycles other than the Otto cycle, but none of them allow the conversion of more chemical energy to kinetic energy and work than are available in the chemical energy to begin with. Mileage figures such as 136.85 m.p.g. with the drag area of a Mustang and the rolling resistance of any tires currently available would exceed that amount by a considerable margin. There are a variety of reasons why such a claim would be made, but getting more energy out than is in the fuel is not one of them. Pending further information, it's very difficult for me to find such claims plausible. If you can supply such information, fine. If not, I guess time will tell.
Thanks,
Rob
From:
Sent: Monday, June 08, 2009 11:00 AM
To: Rob
Subject: Re: Your claims
Hello, Rob: The HP2g not only has been EPA tested, but its fuel economy has been ested in over 8,000 miles of driving in cities, towns, interstates, desserts, mountains and speed tests. The HP2g’s technologies are not those that you know and are familiar with. The engine does not necessarily defy the laws of physics just our prior understanding of how engines are supposed to work. When we are authorized to release the EPA info we will. It is in our possession. Thank you,
Team HP2g
-----Original Message----- From: Rob
Sent: Monday, June 8, 2009 12:17 AM
To:
Subject: RE: Your claims
Can you provide documentation? It’s very difficult to defy the laws of physics.
Rob
From:
Sent: Sunday, June 07, 2009 9:11 PM
To: Rob
Subject: Re: Your claims
EPA tested.
-----Original Message----- From: Rob
Sent: Sunday, June 7, 2009 10:36 PM
To:
Subject: Your claims
I’m afraid that very straightforward calculations show that your claims, as stated, cannot be correct. I wish that they were.
The calculations are at http://hamiltonianfunction.blogspot.com/2009/06/amazing-110-mpg-mustang_06.html.
If there are errors there, I’m sure you’ll point them out.
Rob
Friday, June 05, 2009
A cornucopia of cluelessness
Not satisfied with the gems I located for A potpourri of cluelessness, my research has revealed more examples of complete misunderstanding of the nature of the physical world. If there's "illiteracy," and "innumeracy" then there should be "ill-physics-acy."
For the first, a hat tip to my friend Michael, the publisher of Only In It For The Gold. He posted this gem. The discussion related to the Zap-X electric car by ZAP, a California Corporation specializing in all types of electric vehicles. I've posted about their Zapino, a small electric scooter.
In any case, the post linked by Michael was to an Ecogeek discussion of the Zap-X, which is apparently a moribund concept. But in the comments, "free energy now" replied to a very rational demolition of the claims for the Zap-X with the following:
"Bruce Your comments in compairing the car to cold fusion means that you're assuming that technology can't change the 746w/hp. Is it at all possible that the cars engines are more efficient then your calculations allow for. There are also ways of using capacitors to increase efficiency in heavy load conditions. Technology is changing my friend, and in a lot of situations the nubers just don't add up. My friend has designed a heater which can run indefinitly after a couple of days of being pluged in. He heats his whole house with them, no they don't use cold fusion, just an ingenious design. So just because you can't figure out the math, doesn't mean it's immposible. Peace out"
Amazing. We're going to change a unit conversion factor using technology. Apparently, such a breakthrough will also enable us to develop overunity devices, overcome the Second Law of Thermodynamics, and achieve perpetual motion. I suggested in my comment on Michael's blog that perhaps we should also be looking into the technological possibility of getting more gallons per liter and more miles per kilometer. In fact, why stop there? I will look into employing technology to change the number of centimeters per inch and make myself taller and lengthen my.... But I digress.
Further, as has been pointed out in the comments to the "In It" post, turning electricity to heat is close to 100% efficient, so it's hardly likely to see dramatic improvements.
Moving on, a "Guest" on the CR4 forum replied to a thread entitled "Overall efficiency of gasoline powered cars" with the following:
"Here is a sample calculation of this... change as you need.. Assume the car travels 1 mile at 30m/sec on a flat road(highway speed... 60mph=88ft/sec about 30m/s) and that it gets 36.7 mpg (conveniently chosen to cancel with your 36.7 kw hour/gal). assume the car is 1000 kg. So energy in for 1 mile is 0.5m*v^2 = 450,000Joules Energy put in for 1 mile in terms of gas is 1gal/36.7miles * 36.7kWhr/gal =1kwhr or 1kJoules/sec*3600Sec = 3.6x10^6 joules... so overall efficiency is 0.45/3.6 = 12.5% for this example... change the parameters to get other results... i.e. mass of car, mpg, average speed etc.. adonaldson@calbaptist.edu engineering prof"
The questioner replied to this answer with "Thanks. That's what I was looking for." It's too bad that he or she found it because it's completely wrong. The "engineering prof" calculated the kinetic energy of the moving vehicle and then somehow decided that that's the energy required to move the vehicle one mile. Of course, the kinetic energy of a given vehicle depends only on its speed and has nothing to do with how far the vehicle travels at that speed. To start from a standstill and accelerate to speed requires turning chemical potential energy into kinetic energy, but so does overcoming aerodynamic drag, rolling resistance, etc., not to mention the kinetic energy of the various rotating masses (flywheel, tires, etc.). All of this was ignored.
If this is truly an engineering prof., I grieve for our future. Of course, even if it isn't I'm not all that sanguine. Anyway, I'm sure I'll find plenty of material for my semi-regular session of poking fun at the published factual ignorance on the 'net.
For the first, a hat tip to my friend Michael, the publisher of Only In It For The Gold. He posted this gem. The discussion related to the Zap-X electric car by ZAP, a California Corporation specializing in all types of electric vehicles. I've posted about their Zapino, a small electric scooter.
In any case, the post linked by Michael was to an Ecogeek discussion of the Zap-X, which is apparently a moribund concept. But in the comments, "free energy now" replied to a very rational demolition of the claims for the Zap-X with the following:
"Bruce Your comments in compairing the car to cold fusion means that you're assuming that technology can't change the 746w/hp. Is it at all possible that the cars engines are more efficient then your calculations allow for. There are also ways of using capacitors to increase efficiency in heavy load conditions. Technology is changing my friend, and in a lot of situations the nubers just don't add up. My friend has designed a heater which can run indefinitly after a couple of days of being pluged in. He heats his whole house with them, no they don't use cold fusion, just an ingenious design. So just because you can't figure out the math, doesn't mean it's immposible. Peace out"
Amazing. We're going to change a unit conversion factor using technology. Apparently, such a breakthrough will also enable us to develop overunity devices, overcome the Second Law of Thermodynamics, and achieve perpetual motion. I suggested in my comment on Michael's blog that perhaps we should also be looking into the technological possibility of getting more gallons per liter and more miles per kilometer. In fact, why stop there? I will look into employing technology to change the number of centimeters per inch and make myself taller and lengthen my.... But I digress.
Further, as has been pointed out in the comments to the "In It" post, turning electricity to heat is close to 100% efficient, so it's hardly likely to see dramatic improvements.
Moving on, a "Guest" on the CR4 forum replied to a thread entitled "Overall efficiency of gasoline powered cars" with the following:
"Here is a sample calculation of this... change as you need.. Assume the car travels 1 mile at 30m/sec on a flat road(highway speed... 60mph=88ft/sec about 30m/s) and that it gets 36.7 mpg (conveniently chosen to cancel with your 36.7 kw hour/gal). assume the car is 1000 kg. So energy in for 1 mile is 0.5m*v^2 = 450,000Joules Energy put in for 1 mile in terms of gas is 1gal/36.7miles * 36.7kWhr/gal =1kwhr or 1kJoules/sec*3600Sec = 3.6x10^6 joules... so overall efficiency is 0.45/3.6 = 12.5% for this example... change the parameters to get other results... i.e. mass of car, mpg, average speed etc.. adonaldson@calbaptist.edu engineering prof"
The questioner replied to this answer with "Thanks. That's what I was looking for." It's too bad that he or she found it because it's completely wrong. The "engineering prof" calculated the kinetic energy of the moving vehicle and then somehow decided that that's the energy required to move the vehicle one mile. Of course, the kinetic energy of a given vehicle depends only on its speed and has nothing to do with how far the vehicle travels at that speed. To start from a standstill and accelerate to speed requires turning chemical potential energy into kinetic energy, but so does overcoming aerodynamic drag, rolling resistance, etc., not to mention the kinetic energy of the various rotating masses (flywheel, tires, etc.). All of this was ignored.
If this is truly an engineering prof., I grieve for our future. Of course, even if it isn't I'm not all that sanguine. Anyway, I'm sure I'll find plenty of material for my semi-regular session of poking fun at the published factual ignorance on the 'net.
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