Supplying energy with footsteps yet again

It just won't go away. On my Galaxy Note 3 (which I mostly really like) I have Flipboard. Generally speaking, I like that as well. When I'm biding my time someplace like a Doctor's office, waiting to meet someone, etc., I'll often flip through it. This evening, lo and behold, I found an article from CNN entitled "Harvesting energy from human footsteps?"(which I've since looked up on the web to refer to here, though it's labelled "CNN" but the site is "Click on Detroit).

It features Pavegen, a Company I've looked at before. The concept is the installation of tiles that, when stepped on, deflect and thereby produce electricity via the piezoelectric effect. Does such an effect exist and can electricity be produced in this fashion? Yes and yes. Can the electricity generated thereby be useful in some circumstances? Again, yes. Is this an efficient and effective way to "Transform Tomorrow?" That would be a "no."

Amazingly, Pavegen's CEO, Laurence Kemball-Cook, actually says (and the article duly repeats) that the Pavegen tiles can "produce up to 7 watts of energy with each step." Of course, watts are not units of energy, they are a rate of doing work or converting energy. Kimball-Cook repeats that and, in this TEDx talk, even says "eventually, our vision is that this technology power our cities." This is, frankly, ridiculous and I intend to ridicule it.

The claim is that a single step generates up to "7 watts of energy" (despite the unit confusion, we can infer what they are really claiming if we make some estimates). I went to Vernier's site where  student laboratory measurement, data gathering, and analysis equipment is sold and interesting experiments are described. One of the "Innovative Uses" experiments described was called "Walking Biomechanics Using a Force Plate." There, sufficient data is provided (I'll leave out the calculation details unless requested to add them) to determine that the claim of "up to 7 watts" is not ridiculous, though I'd estimate that a bit under 5 watts is more likely a good average. But we don't care about watts, we care about energy so, based on the data at the Vernier site, the approximately 700 Nt. applied through 0.005 meters over a period of about 0.74 seconds results in kinetic energy delivered to the tile of about 3.5 joules/footfall. This is somewhat confirmed by Pavegen in their graph (at left) of their own office where we can infer that a bit under 250,000 steps produced a bit under 500 watt hours. This translates to about 7.2 joules/footfall. Close enough.

Since there are 3.6 million joules per kilowatt hour, we can say that it would take right at a million steps to generate a kilowatt hour of energy, and that assumes that the piezoelectric system is 100% efficient at converting kinetic energy to electrical energy. Actual data on this efficiency is sparse at best, particularly for those, such as I, who are unwilling to spend $30 to retrieve an article from behind a paywall that may or may not have the information that I want in order to complete a blog post. Nevertheless, I was able to find this document, where it appears that a conversion efficiency of maybe 2.4% can be achieved (yes, you read that correctly).

Thus, our 3.5 joules/footfall is reduced to 0.088 joules/footfall, requiring something on the order of 41,000,000 footfalls to generate a kilowatt hour. I have to say that it seems likely that I'm missing something here. Possibly, 2.4% conversion efficiency is much lower than what these tiles achieve, though I can't find any data that indicates that significantly higher efficiencies have been demonstrated in a laboratory environment. And, in the Wikipedia article on Pavegen, it's stated that "the exact technology is a secret, but PaveGen officials have said it involves the piezoelectric effect and induction by copper coils and magnets."

So it's possible that Pavegen is using something more efficient, so I'll use an upper bound of 3.5 joules/footfall as described above. Here, in an article from Urban Times with a healthy degree of skepticism and yet also open-mindedness, figures from the City of Westminster regarding Oxford Street are cited. Looking there, it's stated that there's an estimated 4.3 million people per week using the street. Urban Times discusses 10 tiles on Oxford Street. So 4.3 million/7 is 614,000 people per day. If they each hit all 10 tiles, the upper bound would be 614,000*10*3.5=21,500,000 joules or just shy of 6 kilowatt hours.

Quoting from the Urban Times article, Pavegen states that

"the pressure of a single footstep creates 4 to 8 watts. It was also calculated that assuming 8 watts is created per step, “during peak hours, one tile produces 12kWh ideally [and] during the off hours, it produces 5kWh ideally” and that “floor tiles, during peak hours will be stepped on 926-1889 times per hour… and 0-719 times during off hours… which works out to about 56 kWh per weekday”.

I can't find that quote from Pavegen, but if it's an accurate quotation, it would imply about 57 million footfalls per weekday. Hmm, I doubt it.

Then, there's the fact that any energy harvested by the Pavegen system is parasitic in nature, in that it's generated by a human converting food energy to kinetic energy. Whatever energy is harvested and wasted by a Pavegen tile is energy above and beyond what the people walking on the tile would otherwise have to exert. It doesn't come from nowhere and it isn't free.

There is likely a place for human generated electricity. As Kemball-Cook points out, there's no need to have the users of gyms merely generate heat on their treadmills, stair climbers, elliptical exercisers, etc. Such folk are going there for the express purpose of burning food energy without a destination or other goal. Such energy might just as well be harvested and, in many cases, it is.

These distractions that allow politicians to have green photo ops and people to get a warm fuzzy feeling about saving the Earth from some oversold "green energy" scheme do much more harm than good. The drastic changes in how we need to live in order to achieve equilibrium with what our planet and our sun can sustainably provide are only put off when people buy into such schemes.

Let Steve Earle describe Pavegen.

US~Observer - Plea Bargaining: Governmental Extortion - Nathan Wente

US~Observer - Plea Bargaining: Governmental Extortion - Nathan Wente:

'via Blog this'

No full disclosure here. I'm not now, nor have I ever been, subject to the offer of a plea bargain. I would argue strenuously against them, at least as now practiced and would advocate removal of judges from the bench if they impose, threaten to impose, or tolerate prosecutorial threats of imposition of harsher sentences for defendants who exercise their right to a trial by a jury of their peers. Those without the deepest of pockets (mine are relatively deep compared to many but nowhere near deep enough) are already tremendously hobbled by the U.S. criminal justice system. The current abuse of plea bargaining multiplies this extreme handicap.

A complete waste of fuel

It's been months since I posted anything here, my blog muse having deserted me. However, my interest in energy and related matters has not abated and my reading has kept pace. It's been over nine years since I started driving to, as best I could, minimize fuel consumption and coming up on eight years in April since I started this blog.

But, despite my interest in driving in an economical way and my Lexus CT200h hybrid car, much of my lifestyle demonstrates an excessive use of energy. Among other examples, I'd offer my airplane, my five or six airline round trips (typically to the east coast and beyond) each year, my family's consumerism, and my involvement in the building industry.

But none of that is quite as extravagant as my interest in NHRA drag racing, particularly the "fuel" categories as they're known, those that burn nitromethane (CH₃NO₂) in their cylinders. These vehicles are fascinating to me, they travel 1000 feet (it used to be a quarter mile, but following the death of Scott Kalitta in 2008 it was shortened) in under four seconds, accelerating to well over 300 m.p.h. Attending such an event in person is a sensory overload not to be missed, you feel the sound from the inside out more than you hear it.

A fueler ("top fuel" and "funny car" are the class names for the nitro burning vehicles) will burn almost five gallons of nitromethane in a 1000 foot run. It will burn about 20 gallons in a round, including startup, warmup, burnout, staging, and the actual run. At full throttle, the engine will use about 1.2 gallons/second. More fun facts about top fuel dragsters can be found here.

A race (weather permitting) will run from Thursday through Sunday with qualifying on Friday and Saturday, and a driver may race four qualifying runs, and, should he or she make it to the final elimination from the field of 16, he or she will race four times on Sunday. So, a successful fuel vehicle will make something like 8 runs down the track at an event, burning maybe 160 gallons of nitromethane. Because it's an elimination format on Sunday, the 16 qualifiers in each of the fuel classes will run a total of 15 two car races, so a maximum of 600 gallons of nitro is burned. The qualifying will add 1,440 gallons or so for a total of 2,040 gallons for the event. Of course, this is quite variable, depending on weather, mechanical breakdown, number of entrants, etc.

I've been scouring the web for video of a top fuel race taken in such a way that I can use the fantastic (and free) Tracker Video Analysis and Modeling Tool (did I mention that it's free?). Such a video would shoot, as much as possible, from a still platform with a wide lens and a line of sight perpendicular to the track. Aerial would be great too, if it met those conditions. So far, no such luck.

The reason I'd like to find it is that I'm curious as to the actual acceleration and the power delivered by the tires to the track. Failing the video, I've found a couple of sources for time, distance, and speed in half-second increments (plus the 0.35 second increment from 3.5 seconds to the finish at 3.85 seconds and 1000 feet. I can get some estimates from those.

Putting the eight data points into Mathematica and generating a linear third order polynomial fit (for a polynomial, it has to be at least third order or else acceleration, the second derivative of displacement, would be constant, something that's clearly not the case), and then finding the derivative (acceleration), it looks like the Grubnic's dragster is accelerating at about 4.5 Gs at 1 second. As a sanity check, distance traveled ~s= \frac{1}{2} a t^{2}~ where ~a~ is average acceleration over the distance (and assuming initial conditions of 0 distance and 0 speed), so average acceleration ~a=2s/ t^{2}~. Substituting 1000 feet for ~s~ and 3.85 seconds for ~t~, ~a~ is about 135 feet/second², or about 4.2 Gs. At 0.25 seconds, it looks like acceleration is in the vicinity of 5.2 Gs.

Given that a top fuel dragster weighs about 2320 pounds, we can determine the power applied by the tires to the track. We can find the force from the mass and acceleration. Let's use the situation at one second. We have a mass of 1052 kg accelerating at 43.98 ~m/s^{2}~, so the force is 46,285 Nt. Since force*speed is power, and the vehicle is moving at 53.82 meters per second, we can estimate that about 2.5 megawatts represents the rate that the tires are performing work. This is about 3,340 horsepower. It's stated on various web sites that the engines generate between 8,000 and 10,000 horsepower. As far as I know, a top fuel nitromethane burning engine hasn't been tested on a dynamometer. I've seen statements that no dynamometer exists that can measure that level of power, but I believe that such instruments do exist. I think the problem is that the engines can't survive at full power long enough to achieve accurate measurements.

As to the difference between, say, 8,500 and 3,340, a lot is lost in the clutch system, and it takes at least 700 horsepower just to drive the supercharger. Further, in the use of ~f=ma~, it's actually ~ \Sigma f=ma~ where ~\Sigma f~ is the sum of forces on the vehicle. Most significantly, I didn't include aerodynamic drag or tire rolling resistance, both of which will be quite significant with tire pressure at around 7 p.s.i.g. and speed in the 100 m.p.h. range. Given that the exhaust and the wing both produce down force (enabling traction at higher power than would otherwise be possible) and the low modulus of the tires resulting in huge hysteresis, rolling resistance is likely to be a more significant component of overall net force against the acceleration than is true in street cars.  Further, at higher speeds, the drag of the vehicle is very high, in particular due to the induced drag generated by the wing at the rear of the vehicle. Thus, the force applied by the tires to the track must not only overcome the inertial mass of the vehicle, it must overcome aerodynamic drag and rolling resistance. Thus, engine horsepower in the 8,500 or even 10,000 horsepower range seems quite plausible.

Now, I strongly suspect that it's much more complicated than that, particularly in the first second or so. Sadly, the inability to find a video that I can analyze makes it impossible to do any better, but I'll keep on the lookout.

I've typically wrapped up posts with a song, but a top fuel dragster makes a music all its own.




Ps: I'll be curious to see if any of the denizens of Guy McPherson's "Nature Bats Last" Near Term Human Extinction community, with whom I've been engaged in some back and forth lately, wanders back to my blog. A couple did so earlier and noted that I'm not a climate scientist, I'm pretty sure this topic will convince them to discount me completely (if they haven't already done so). On the other hand, this post may fit well with the McPherson/doomer/"we're special because we know that we're all doomed and you don't" crowd. After all, as they see it, nothing (to be read literally as "no thing") we do can help, what difference can it make if we burn some rubber and nitromethane?

A real-world example of the effect of driving habits

Gratuitous Kari Byron photo courtesy of Discovery Channel
from their Hypermiling episode

As readers of this blog will know, I drive a Lexus CT 200h, a hybrid vehicle that's basically an upgraded interior and redesigned exterior wrapped around a Toyota Prius drivetrain. While I don't exert the maximal effort in hypermiling, eschewing, for example, the "pulse and glide" technique, I do utilize several of the techniques. Doing so has yielded an aggregate mileage, since the purchase of the vehicle three years ago, of 51.2 m.p.g. over the course of over 57,000 miles.

Early this year, a person I met through my Company purchased a CT 200h and agreed to track and log fuel economy and share the data with me. From the start, Arezoo mentioned that she'd not be willing to drive the way I do. In particular, she wasn't interested in maintaining a cruise controlled speed of 55 m.p.h. on freeways. She's mentioned 80 m.p.h. on a couple of occasions, though I don't know what she's able to average.

I was very interested in getting her reports so that I could have a comparison between normal driving in a CT 200h and my driving. The second set of results are now in, and Arezoo has recorded an overall fuel efficiency of somewhere just north of 38 m.p.g. (she is slightly less compulsive about recording data than I am). Thus, she uses about a third more fuel than I do to travel a given distance.

Image courtesy http://gunnip.com/blog/2012/04

Arezoo has burned about 208 gallons where, over the same course, ceteris paribus, I would have burned about 156 gallons. Her average cost of fuel was about $3.80, and thus she spent just under $200 more than I would have. One way of looking at this is that Arezoo judges her satisfaction in not driving the way I do to be worth at least $200 but, frankly, that's the wrong way of looking at it. From a purely economic perspective, the time that she saved was extremely likely to be worth far more than $200. The time cost of my 55 m.p.h. maximum has been a frequent subject of my posts.

Unfortunately, I have insufficient data to determine precisely how much time I lose, though I can approximate it and even determine it as somewhere along a curve in a three dimensional plot. I did such an approximation in one of the posts linked above, figuring that I lose in excess of 40 hours per year. But the governing set of equations is underdetermined and thus I can't nail it down. And I know I'm not saving the world, or even enough for retirement, but the nickels and dimes do add up.

Why Dropbox?

I subscribe to "Quora," which is a place where people ask questions and people who believe that they have some subject matter expertise in the area of the question will provide answers. Naturally, you can select areas of interest and new questions and answers in those areas come to your email inbox on a regular basis with links to the full set of such questions and answers. I'm a big fan.

I'm also a big user of Dropbox, a "cloud" storage site that syncs with all of my devices (and I have devices operating on Android, iOS, macOS, and Windows - nothing Linux yet), and those two sites intersected with someone asking "Why is Dropbox more popular than other programs with similar functionality?" I found the following answer from Michael Wolfe to be both dead-on accurate and hilarious:

Well, let's take a step back and think about the sync problem and what the ideal solution for it would do:

• There would be a folder.
• You'd put your stuff in it.
• It would sync.

They built that.

Why didn't anyone else build that? I have no idea.

"But," you may ask, "so much more you could do! What about task management, calendaring, customized dashboards, virtual white boarding. More than just folders and files!"

No, shut up. People don't use that crap. They just want a folder. A folder that syncs.

"But," you may say, "this is valuable data... certainly users will feel more comfortable tying their data to Windows Live, Apple's MobileMe, or a name they already know."

No, shut up. Not a single person on Earth wakes up in the morning worried about deriving more value from their Windows Live login. People already trust folders. And Dropbox looks just like a folder. One that syncs.

"But," you may say, "folders are so 1995. Why not leverage the full power of the web? With HTML5 you can drag and drop files, you can build intergalactic dashboards of statistics showing how much storage you are using, you can publish your files as RSS feeds and tweets, and you can add your company logo!"

No, shut up. Most of the world doesn't sit in front of their browser all day. If they do, it is Internet Explorer 6 at work that they are not allowed to upgrade.  Browsers suck for these kinds of things. Their stuff is already in folders. They just want a folder. That syncs.

That is what it does.

Ahhh.... 

"Solar Freakin' Roadways!"

Artist's rendition, courtesy Solar Roadways

A commenter brought up the "Solar Roads" concept with this link. I'd seen it mentioned in the past but had never really dived in to analyze it. In looking around, there are a fair number of youtube videos claiming to debunk the concept, as well as an exuberant video singing the praises of the idea (the one from which the title of this post came). And Julie and Scott Brusaw, the inventors of the concept, have both SBIR grants and a successful Indiegogo campaign. And they mount a defense against the so-called "debunkers" here.

So what is the Solar Roadways concept? The idea is to replace typical pavement materials (asphalt, concrete) with hexagonal tiles that contain solar photovoltaic cells along with circuitry and LEDs. The cells and circuitry are covered with a textured clear glass to provide traction for vehicles and protection for the electronics. Among other things, the solar roadway would harvest solar energy to provide distributed power, heat the tiles to melt snow and ice (though this would be done, as I understand it, with grid power since the energy demands to melt solid water exceed what the solar panels could provide), light the LEDs for lane markings, messages, etc., be sensitive to load and thereby be able to signal through the LEDs that there is a pedestrian or animal in the roadway, and a variety of other ideas.

So, does such a concept have any credibility? To start, Scott Brusaw has significant engineering background and doesn't appear to be either an idiot or a charlatan. The Brusaws recognize that the tiles won't provide electricity at night and thus, like a typical home solar installation, utilize the grid as a "storage medium," that is, they are a source of electrical input to the grid when the sun shines to the extent that their production exceeds their own demand (energizing LEDs, etc.), and utilize electricity from the grid to accomplish their purposes when it does not.

But let's think a bit. At the Renewable Energy Resource Center (a project of the National Renewable Energy Laboratory, RREDC & NREL respectively) there's a very nice page where we can estimate solar irradiance. The page allows us to choose dates, configurations, etc. Using average irradiance, March, horizontal flat plate (to represent a road), I get the map at left. It represents average everything (March at the equinox, average irradiation, etc.).

Let's take an average location, say, Kansas. It looks to me like about 4.5 kWh/m^2/day (kilowatt hours per square meter per day) would be a good number to use. Now, the Brusaws calculate using 18% efficiency in their cells. I'll charitably assume that the textured glass lets 100% of the incoming sunlight through to the underlying photovoltaic cells. Thus, the cells can capture 0.18*4.5=0.81 kWh/m^2/day. Where I live, that's worth a bit under a dime.

But suppose that Kansas (or wherever) has a feed-in tariff for renewable energy. Feed-in tariff rates are quite variable even by state, but let's generously use $0.30/kWh. That makes the electricity produced by a square meter of photovoltaic cells in the Solar Roadway worth a bit under a quarter, but let's call it $0.25. Of course, the DC produced by the cells must be converted to AC to feed the grid. An advanced "micro inverter" to accomplish this task is about 96% efficient, so that the 0.81 kWh is reduced to 0.78 kWh, worth about $0.23. In a year, the square meter would generate about $85.

The Brusaws claim that a tile is designed with a lifetime of 20 years. I doubt this, but let that pass. This would mean that the square meter of tile would produce, in its lifetime, $1,700 worth of electricity. Yes, rates may rise, but I didn't discount the cash flow to represent the time value of money. Further, it's unlikely that feed-in tariffs will endure as solar becomes more widely adopted, and feed-in tariffs aren't universally adopted in any case. Thus, I'm claiming a wash there.

Now, the assumptions here are, without a doubt, generous. No adjustment was made for transmission of the glass wearing layer, for any accumulation of road grime, blown in dust and dirt, portion of pavement shaded by vehicles, etc. But I will adjust for the fact that the LEDs, electronics, etc. take a significant portion of the area of each tile presented to the sun. While no figures are given in Solar Roadway's site, estimating from the various photos, I think that no more than 75% of the area of a Solar Roadway pavement would generate electricity. This reduces that $1,700 per square meter of paving to $1,275 and the annual revenue to a bit under $64. It reduces the electrical input to the grid to 0.585 kWh per day per square meter.

Now, the power required to have the LEDs visible in bright daylight at, say, 17 meters might be on the order of 300 watts/square meter of lighted area. This may seem like a lot, but consider that only a very small portion of any paved area is lit (see the graphic at the top of the post). If we conservatively assume that the worst case is that 5% of paved area may be lit, that would constitute 15 watts. And this is for daylight, the LEDs could (and, no doubt would) be dimmed at night. I'm going to estimate that this would require 240 watt hours/day or 0.24 kWh per day per square meter. Note that this is (.24/.78) = 0.308 or about 31% of the generating capacity of a square meter of tiles. This reduces the $1,275 to about $880 and the $64 to about $44. It reduces the electrical energy fed to the grid each day to 0.40 kWh per day per square meter.

I have not been able to find a cost estimate for a tile on the Solar Roadways web site, but if I use what I can find for tempered glass, photovoltaic panels, and electronics, I can (very roughly) estimate that square meter of these tiles might cost around $250 at wholesale prices. This doesn't include installation. I would estimate that a square meter of installation might take another $100 per square meter for a total of $350. Thus, an installation might pay for itself in eight years or so. That's not really so bad. And note that we don't ask concrete or asphalt pavements to generate any income at all (tolls don't count - the same could be done for a Solar Roadway). Note that this doesn't count the associated infrastructure for cable runs, etc. Add another $150. Since much of the pertinent information with respect to composition, dimensions, etc. isn't given, this is the best that I can do.

The Brusaws go on to claim that replacing the entire paved area of the US with Solar Roadway tiles could generate three times the electricity usage of the Country. Of course, this ignores the intermittency issue which, for a local installation, can use the "grid storage" mentioned above but which is out of the question when trying to replace the entire electrical generating capacity of the Country.

But let's carry on undaunted. I can use numbers from this Wikipedia page to estimate that approximately 74 billion square meters of land in the US is paved. Taking this number times the approximately (on average assumptions for everything) 0.4 kWh/day times 365 days per year, we can estimate that replacing all paving with Solar Roadways might generate a bit over 1.09*10^13 kilowatt hours of electricity. Let's just go with 10 trillion kilowatt hours. Here we find that in 2012, US electricity demand was 3,826 billion kilowatt hours, or 3.8 trillion kilowatt hours. Thus, the Brusaws' contention is in the right ballpark (given the proviso above).

What about the Brusaws' contention that the a Solar Roadway could contribute to the charging of an electric vehicle by induction? Let's assume that the car is traveling at the optimal time of day in cloudless skies. The Roadway can deliver something like 180 watts/meter^2 (18% efficiency * 1000 watts/m^2). The vehicle might be 1.75 meters wide and, at 55 m.p.h., spend about 0.04 seconds to traverse a meter. The Solar Roadway can deliver 1.75*1*180 = 315 watts from this area. In 0.04 seconds, it can deliver 0.0035 watt hours of energy. Suppose that an EV needs 10 horsepower to maintain a speed of 55 m.p.h. This is about 7500 watts. It will spend that same 0.04 seconds on a meter and thus need about .083 watt hours of energy. The Solar Roadway can thus (neglecting all other losses) supply about 4% of the energy requirement of this very efficient car. Of course, only a fraction of the roadway would be drawing power, let's say 15%. Thus, maybe 25% of the energy of the vehicular traffic could be supplied if all EVs were that efficient and every vehicle was an EV. Of course, not every vehicle is not an EV and thus this may actually be a significant contributor. Again, a whole lot of estimates went into this and many numbers were quite optimistic.

Finally, what would be the cost? This is even a harder number to estimate. The Brusaws contend that the tiles could, in many cases, be mounted on existing pavements. I seriously doubt that, overlaying pavement is a very difficult civil engineering problem. Profiles must be maintained, gradients must be within specifications, etc. Nonetheless, let's just take $500*74 billion, for a total of $37 trillion. Keep in mind, however, that these existing pavements will ultimately need to be repaired and replaced as they wear out. And a ballpark figure for construction of a new asphalt or concrete pavement is on the order of $150 per square meter.

Admittedly, much of the above is based on estimates that may or may not closely match the real world. Nevertheless, I see nothing that makes me think that the concept is preposterous. I believe that the most important data to acquire is the performance of the tiles under continuous wheel loading over long durations in varying temperature, moisture, and mounting/subsurface conditions.

And one additional major consideration, completely unaddressed by the Brusaws, is the need for paved surfaces to not simply shed all rainfall to storm water management systems for discharge to a lake, river, or ocean. In this regard, materials scientists are hard at work on pervious concrete and pervious asphalt paving systems that drain water to the subsurface layer for absorption into the underlying earth. There's no possibility of this with the Solar Roadway system, and thus an eco-friendly storm water handling system must be made a part of any such design.

Update: A tweet mentioned that the Brusaws had, in fact addressed drainage. A Google advanced search took me to this page. I haven't had time yet to evaluate the plausibility of their scheme, but I was incorrect in the paragraph above to state that the issue was "completely unadressed." My apologies to the Brusaws.

Feigning literacy, nothin' up my sleeve

Image courtesy of Chris Butler, Big Chris Gallery

I look at various climate related sites, both those who are skeptical of what I'll call climate disruption caused by the products of mankind's burning of fossil fuels and those who accept the theory (using "theory" here as a scientist would use it, analogous to, say, Newton's theory of gravitation). One of the most frustrating things I find is writers who present a veneer of scientific literacy but, upon even cursory investigation by anyone with a reasonable yet far short of specialist knowledge (e.g., myself) are easily revealed to be nonsense. Yet the scientific veneer ("look! charts! equals signs!") can lead people with almost no scientific or mathematical literacy to place credence in this nonsense. And, sadly, that latter group is a very large one.

A good example is to be found here. Those who follow the ebb and flow of the so-called debate around climate disruption will likely have heard of the "hiatus" in warming, that is, a slowing down of the rate of increase of global temperature. Given the demonstrable increase in energy retained by the earth/ocean/atmosphere system (for what is, in my opinion, a silly if not counterproductive "measurement" of this heat, see here) because of our greenhouse gas emissions, scientists have advanced theories for the so-called "missing heat." As best I can determine, the leading theory is that the oceans are heating and doing so to greater depth than had been anticipated.

But Anthony Cox is having none of it. He reproduces the graphic graphic at left. It charts a time series of "Change in Total Heat Content" data from 1955 through (apparently) 2014. As an aside, my pedantry requires that I mention that "heat content," though widely used and accepted, is poor terminology. Heat is an interaction between a system and its surroundings resulting in a change in internal energy of the system. Temperature, in turn, can be (loosely) considered to be a measure of one specific component of average internal energy.

In any case, Mr. Cox objects, and provides charts showing a calculated equivalent temperature rise in degrees celsius. I'm not sure why he bothered to calculate. The source of such data, NOAA's National Oceanographic Data Center, provides a chart with degrees celsius as the ordinate in the same set of charts as that from which the "heat content" chard is reproduced. Such a chart is here and, in fact, the charts showing heat content are computed from temperature measurements.

But what's the difference? Why does one chart show the data in joules and the other in degrees celsius? The joule is a unit of energy. One joule is an extremely small amount of energy in comparison to everyday experience; the heat energy available in a single piece of plain M&M candy is more than 14,000 joules. A gallon of gasoline releases about 125,000,000 joules when completely oxidized. That's why the heat content chart has such huge numbers. What you see on the vertical axis is measured (actually, computed from temperature measurements in the ocean vertical profile) heat content with a reference number subtracted. Accordingly, this is an "anomaly," and each "tick" on the vertical axis represents a 10²² (1 followed by 22 zeros) joules from the reference period. It does not represent the "total heat content" of the oceans. It represents gains and losses in comparison to the reference period.

To the left is the data showing temperature (again, as an anomaly) over the period. Note that this was taken straight from the the NODC web site, no need for the calculations performed by Lucia at the "The Blackboard."

Mr. Cox contends that the heat content anomaly in joules is used because the big numbers look more scary then the same data presented as temperature anomaly in degrees celsius.

This is simply untrue. The amount of energy that will heat a cubic meter of water by 1 degree celsius will heat about 3,100 cubic meters of air (at sea level pressure) by that same degree celsius. This is due in small part to the higher specific heat of water but mostly to water being about 1,000 times as dense as air (again, at sea level pressure). Looked at another way, the amount of energy required to heat the upper 700 meters of ocean worldwide by 1 degree celsius would heat the ENTIRE atmosphere some 170 degrees celsius (assuming that the specific heat of air is constant as temperature changes, which it is not).

Now, is the interaction between incoming solar energy, outgoing long wave radiation, ocean circulation, heat transfer, etc. as simple as this calculation? Of course not. That's why scientists study these things, measure the relevant parameters, seek hypotheses that explain the measurements, etc. Are there significant questions to be answered with respect to the data presented and how it's measured? Yes. Are scientists trying to answer these questions? Yes. That's what science is.

But the conclusion is that energy (referred to by NOAA as "Heat Content" and tracked as an anomaly) is an entirely appropriate way to picture one component of the effect of greenhouse gases on our ocean/atmosphere system. It is NOT a nefarious way to be able to insert scary large numbers into a chart. And, to reemphasize for yet the third time, the same set of NOAA charts that shows the energy anomaly in joules shows its effect in degrees celsius as well. So who really has deception as their goal?

Jumping the shark*

In other posts, I've made myself clear on what I think is true (I don't say "believe" because I don't want to provide grist for those who say "climate alarmists are more akin to religious zealots than scientists") regarding climate change. And I certainly see vast evidence of propagandizing employed by those who either truly don't believe  think that our carbon dioxide emissions are harmful, or those who profess such beliefs conclusions for other reasons.

On the other hand, now and again I run into something from those who agree in large part with my conclusions regarding disruption of the climate via the products of our burning of fossil fuels that makes me slap my forehead in dismay. An example of this is a paragraph extracted from New South Wales' (Australia) "Road Users' Handbook." On page 39 of that publication, I find the following:

"SAFE DRIVING DURING SEVERE WEATHER EVENTS"

"It is anticipated that current weather patterns will progressively change and  become more unpredictable as a result of climate change. Climate change is the impact on the planet due to greenhouse gas emissions which will increase global temperatures. Climate change is expected to cause unpredictable weather events and conditions such as extreme heatwaves (sic), storms, flooding and bushfires (sic). Driving during extreme weather events or conditions should be undertaken with care and caution..."

It's certainly the case that climate models and fundamental geophysical considerations indicate that severe weather events will increase in various locations because of the displacement from equilibrium in the Earth/atmosphere/ocean energy system due to our emissions of greenhouse gases.

Many, though, will regard this language as a subterfuge to insert a political agenda into a government publication that has nothing to do with the science (and political discourse) of global warming. And, to the driver encountering such conditions, what in the world does it matter to him or her what caused them? It's most emphatically not the case that extreme heatwaves, storms, flooding, and bushfires are new phenomena, only noted in the anthropocene.

Along with inane, counterproductive pieces such as "No Pressure," these sorts of needless, over the top insertions of very real concerns about climate disruption into unrelated publications add nothing and provide ammunition for those who want to point fingers and say "See? It's all a plot on the part of the one-world government manipulators to surreptitiously lead the sheeple to the slaughter." Just say no!

And finally, no such post would be complete without TEOTWAWKI:



*See, for example, this Wikipedia article  or this Urban Dictionary entry for definitions of "jumping the shark."

It's all in the presentation

Graphic courtesy of NOAA

In the process of trying to understand the trajectory of our climate from a layperson's point of view, albeit one with at least a moderate level of sophistication with respect to basic physics and mathematics, I run across an awful lot of blogs. Some are hosted by actual climatologists, some are hosted by deeply interested people with extensive scientific knowledge but who are not climatologists, some are hosted by interested (and talented) amateurs. These bloggers are firmly convinced that mankind's emissions of carbon dioxide and other greenhouse gases present an imminent danger to our way of life.

There is an alternate universe of blogs from those who are either actually skeptical of any effects we may have on climate or who, for various reasons, write as if they are. Such writers range from those who are openly hostile to those who profess uncertainty. Again, these fall into groups. And again, these writers have vastly differing degrees of scientific sophistication, ranging from those whose career involves the study of climate (though skeptical professional climatologists are few in number) through, again, talented amateurs.

Some of those in the second group, however, are simply hacks. Such a one is the publisher of "Greenie Watch," published by John Ray, Ph.D., out of Brisbane Australia. His latest post discusses the charts one often sees that show global temperature anomalies. These numbers show the deviation from some reference value, typically a long-term average. Such a chart is at the top of this post.

Dr. Ray doesn't like these, and instead shows whole degrees Fahrenheit starting from zero (already questionable, since 0 degrees Fahrenheit has no significance). That results in this:

The point is, of course, that any trend in temperatures looks trivial in comparison to the distance from zero to the measured (calculated?) temperatures.

I thought I'd try something similar. Though I don't know anyone specific, I'd imagine that someone or another has developed a fever in the last 30 days. Let's plot such a person's temperature anomaly:

Woah. This guy had best see a doctor, stat! On the other hand, have a look at this:

I guess he was worried about nothing. And yet these two plots show precisely the same data, one in degrees Fahrenheit above or below 98.6, the other in Kelvins from absolute zero (a zero that, at least, does have some significance).

I may go back and refine these plots, they certainly aren't pretty (I'm working on coming to grips with Matlab and, while some of the manipulation is straightforward, the plotting features frustrate me). But they certainly get across the idea that, in many cases, it's quite straightforward to display data to suit one's agenda. I could almost say, to deceive.

Breakdown Dead Ahead

Image credit: Texas A&M University-Galveston
Dr. Patrick Louchouarn

Last week, I was in Washington, DC (well, actually at National Harbor, a very cool place) for the TechConnect World Innovation Conference and Expo. One component of that conference is Cleantech Energy and Efficiency, the portion I attended. In particular, there have been papers presented on research in energy efficient and low carbon construction materials, something in which my firm is very interested. But, while those topics may be grist for future posts, they aren't the topic for this one.

There are two mutually complementary reasons to be extremely concerned about our (and by "our" I mean inhabitants of planet Earth, not only US residents) energy future. One is the unfolding crisis of the availability of cheap and easy fossil fuel resources (for a brief summary see this primer). The other is the strong likelihood (not certainty) of major disruption in our planetary climate system due to the combustion products and byproducts of producing energy from fossil fuels.

Two weeks ago, while in Houston, TX, I met my college friend, Dr. Michael Tobis for dinner. Dr. Tobis, as I've mentioned previously, is the editor-in-chief of the site Planet3.0. He has a strong background in modeling, climate science, and system dynamics as well as a keen interest in the interface between science, journalism, and public discourse.

Michael and I see many things very differently. But we were discussing the potential societal train wreck dead ahead and what might be done to avert its worst consequences. Michael said "carbon tax" believing, I think (judging by his surprise at my response) that I'd strenuously disagree. In fact, I agree absolutely and, were I King,  I would make such a decree immediately.

Such a tax has many things favoring it. It attacks both problems  directly, i.e. declining availability of "cheap" (both in terms of financial cost and energetic cost) fossil fuel energy and climate disruption due to combustion products and byproducts of fossil fuels. It is Pigovian in nature (in brief, it attaches a price to externalities, that is, negative consequences not paid for by the producer, that the market fails to capture without it) and thus achieves a "societal good" by directly increasing the price of fossil fuels, thereby reducing demand for them and creating a resource for dealing with the consequences of their use and for investment in alternatives. The diagram at the top of this post will look generally familiar to those who've taken Econ 101 and 102. See this page (from which I shamelessly lifted the diagram) for an in-depth explanation.

Clearly, such a tax is regressive (in the colloquial sense of "affects lower income people proportionally more than those of higher income" rather than in the strict sense of the rate decreasing as consumption increases) and this would certainly have to be accounted for in the deployment of the government income generated. I'll post in the future as to what level I believe would represent the best combination of most effective and least economically damaging. Hopefully, further thoughts and research can lead to an idea of how it would be implemented and how the resulting funds would be distributed.

Of course, the pitfalls are many. Anyone in the business of selling fossil fuel based products and services will fight such a tax tooth and nail. The number of groups with differing opinions on what to do with the funds would be huge and all would be strident in their objection to whatever final determination was made. Every group would think that they got the short end of the stick. And Republicans (of which I used to be one) can't be elected unless they claim that a new era of US energy independence is upon us if only the Washington DC bureaucrats, tree-huggers, and alarmists would get out of the way and that anthropogenic climate change is a hoax/conspiracy/get rich scheme for elitist academics.


So, until the engine of the train is already over the cliff and the passengers in the first few cars are screaming, I think that the prospects for such a tax being implemented are bleak at best. Thus, I think that there's a Breakdown Dead Ahead.

Que sera sera?

Image credit: James Kuhn

For years now, I've been aware of a couple of things (more than a couple of course, but a couple that are germane to this blog and this post): the peak fossil fuel phenomenon and its implications for the current profligate use of energy; and the climate change/climate disruption/self-poisoning consequences of our current ransacking of planetary resources of all types.

I've come to realize that I'm (that is, I personally) iconic in several ways. I'm aware of these things and yet, as mentioned in quite a few of my posts which I'm not feeling like hunting down to link, my family and I are profligate users of energy, profligate producers of refuse of all kinds, and profligate consumers of "stuff." And I work in an industry whose purpose is increasing the extent of the built environment. What explains this?

I think there are several components to this behavioral dissonance. It seems to me that evolution has equipped our species to be tribal, acquisitive, and sexual (I know that I read that particular formulation somewhere so I don't claim to have originated it, but I can't find the source of the original quote). These are among the key characteristics that enabled our ancestors to survive and procreate with little in the way of physical advantage (speed, claws, size, teeth, etc.) in hostile environments. Planning for the long term was not immediately helpful, and providing for oneself and one's family in old age was irrelevant. Making lots of babies so that at least a couple would survive, getting as much stuff (food) as possible, and banding with others against the "world out there" would make for the best chances for the "selfish gene" (note that I carry no water for Richard Dawkins) to carry on.

There's also a related characteristic I've seen in myself and many others. I refer to it as the (don't know if the phrase is mine or it's been around) "hamburgers and fries may kill me but this hamburger and fries won't" rationalization. I can always be more Earth-friendly and energy conscious after I build my self-sufficient, off-grid home in Agua Dulce. And anyway, what difference can poor little me make?

And, dipping into sociology, I think that these same characteristics tie in very well to the capitalist system in which quarterly results, short term benefits, steep discounting of future returns, I win if you lose zero sum activities, etc. reign supreme. The capitalist system models, in a very direct way, the tribal and acquisitive components of our individual makeup.

It's no great surprise, then, that many of us as individuals and many modern societies find ourselves and themselves helpless in assessing and actively taking effective steps to mitigate the current situation of declining ability to extract cheap and easy resources of all kinds and the continuing degradation of our planetary life support system by the detritus of our lifestyle.

There are many who have endeavored to paint a realistic picture of the way things may unfold and to provide some manner of guidance as to what individuals and societies might do to avoid rushing headlong over the cliff and into personal or societal oblivion. I've linked and posted on a couple of them, including John Michael Greer, the Archdruid and James Howard Kunstler (the former in more complimentary terms than the latter). Another site that attempts to take on this complex of issues is Planet 3.0, a site whose editor-in-chief, Dr. Michael Tobis, is a friend I've known since my first attempt at college in 1971.

And there are the techno-utopians such as Amory Lovins of the Rocky Mountain Institute who, while not claiming that the transition to a society with dramatically less access to cheap and easy fossil fuel energy will be a piece of cake, nevertheless posit that our trajectory can be monotonically upward if only we follow their prescription.

Finally, there are the complete doomers, such as Dr. Guy McPherson of the blog "Nature Bats Last" who say all is lost, our species will be extinct within a generation or two, and that attempting to do anything about it is, at best, a distraction. After that, the world may start to heal the wounds we've inflicted without us. Dr. McPherson sarcastically and preciously refers to any suggestion of ways to avoid total annihilation as "hopium."

Image credit: Darrel Rader via IBM Developer Works

So yes, I've done a lot of reading on these topics and continue to do so. Yet my previous post was on noodling with some calculations while on a 33 hour construction related business round trip to Thailand on a Boeing 747-400. Well, THIS airline trip won't doom the world...

I want to take some time in future posts to compare and contrast the positions and approaches of such as the Archdruid with those of the position of Mr. Lovins. Like so many other issues, there's a whole lot that needs to be known in order to decide where to place my bet. But, in the meantime, I'll go to work tomorrow trying to decide how to accomplish the needed inspection and testing of welding being done in Thailand for a Courthouse being built in San Diego.

What do I personally think will happen? At this point, I'd predict a descent of initially slow but increasing speed into a world of isolated, relatively self-sufficient communities living in, at best, an environment of tolerable comfort. And I predict lots of mayhem on the way there. Hopefully, it won't be as fast and as brutal as is predicted by Dmitry Orlov.

Update: I thought long and hard about whether to tweet a link to this post from my work-related Twitter account. The post doesn't fit the construction industry narrative very well. But, in the end, I decided that if I'm too chickenshit to do that, I should just shut up.

Stopping time

Image credit: http://www.mastermarf.com

I recently completed a business trip to Thailand entailing some 33 total hours in the air. My client won't reimburse business class, let alone first class, so "economy plus" was the best that I could do. On Delta, that gives me 4" of extra legroom and a few extra degrees of recline in the seat. That doesn't sound like a lot but it makes a huge difference!

In any case, while on such flights, I bring along work and recreational reading and, typically, attempt to get some sleep, I also tend to give some thought to something to do with the flight. For example, I've made several posts about using the accelerometer in my smart phone to determine acceleration and takeoff speeds and distances. On another trip, I used the pressure sensor in my Galaxy Note 3 to estimate the cabin altitude of the aircraft in cruise. While there are apps that will automatically give you altitude based on the pressure sensor, I hadn't (and haven't) yet installed one so it was an interesting little exercise in calculus, fluid mechanics, and the ideal gas law to estimate that the cabin altitude was about 6,700 feet.

On the most recent trip, I was wondering about my relationship to the sun as we chased it (westbound) or rushed toward it (eastbound). It occurred to me that, for any speed up to about 1040 m.p.h., there's some latitude where that westbound speed would keep the sun at the same position in the sky. At the north or south pole, if the sun were visible at all, you wouldn't even have to move, you'd only have to rotate.

In any event, it was a pretty trivial exercise in spherical coordinates to find the appropriate latitude at a speed of 500 m.p.h. (a reasonable speed for the B747-400 at altitude flying into a typical not too strong headwind). For any speed, the equation is ~ \theta =\arccos\left(\frac{24v}{2 \pi R}\right)~, where v is the speed in miles per hour and R is the Earth's radius in miles (of course, any units of speed, i.e., length/time, and length will work so long as they're consistent and the "24" is changed to the number of whatever time unit that's used that comprises a day). Substituting 500 for v and 3,957 for the radius, I find that a direct westbound path at about 61.14 degrees north (or south) latitude will make time stand still. Or, at least, it will make the sun stand still in the sky. Were I to walk at 3 m.p.h., I'd need to be at about 89.8 degrees north (or south) latitude. This would be around 11 miles from the north (or south) pole.

Of course, I'd be jolted forward a whole 24 hours each time I crossed the International Date Line so, sadly, I can't use this method to stay Forever Young.

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