“Be kind, for everyone you meet is fighting a hard battle” - Often attributed to Plato but likely from Ian McLaren (pseudonym of Reverend John Watson)

Sunday, January 03, 2016

More green hype (though, apparently, well-intended)

Image credit: Wikipedia
It's been a while (and this isn't my first such apology) since I've posted an article. The long-awaited article (actually, articles) on the cost effectiveness of renewable energy with storage as base load and/or dispatchable electrical energy has taken a lot more time than I thought. And, of course, life intercedes. Nevertheless, lest I lose my faithful audience, I wanted to post.
Through a variety of feeds, I was led to a series of innovations by Manoj Bhargava, the founder of 5-Hour Energy (quite a few little bottles of which I've slugged down). He's committed to give away 99% (or 90%) of his (as of this writing) $4 billion dollar fortune. One venue for his philanthropy is his engineering and invention facility, called Stage 2 Innovations. Bhargava and his people have created a series of videos highlighting some of their innovations and concepts. The site is called "Billions in Change" and you can watch a 43 minute video on three of the concepts here or watch the shorter video that involves the subject of this post here
Image credit: video screen capture from "Billions in Change,"
Capture by Treehugger.com

He's encouraged his engineers to do big things, and one cited example is the "Free Electric hybrid bike." The idea is that a human peddles a mechanism (similarly to operating a recumbent bicycle) that turns a large flywheel. In turn the flywheel operates a generator which charges a battery bank. If you think that such a concept is unheard of, I invite you to look here or here or here or... well, Google is your friend. So what is special about this unit?

It certainly appears to be very well made and the large flywheel should ensure very smooth running. On the other hand, in comparison to the more standard versions linked above, it's sure to be dramatically more expensive to produce. But, if Bhargava is going to give them away, as they might say in Australia, good on him.

I do think that the claims are quite misleading though. Multiple times in multiple places, it's stated that a user can "pedal for an hour and have electricity for 24 hours." While this is, no doubt, true, it certainly won't be a lot of electricity. It's also true that much of the developing world is either completely without electricity or suffers extremely intermittent availability.

But let's think. A world class (as in, the very best in the world) cyclist can deliver about 400 watts for an hour. I strongly suspect that someone in a village in an underdeveloped country would be fortunate to deliver 150 watts for an hour. It's certainly the case that the cyclist to flywheel to generator to battery to load efficiency will be significantly less than 100%, I'll be optimistic and use 80%. So we'll have 120 watt hours available to do work. And we're going to use this energy over a 24 hour period and so our average load can be 6.25 watts. A single LED bulb with approximately the luminous intensity of a 60 watt incandescent bulb will use around 7 watts.

Now, we won't need the single bulb during the daytime or when sleeping, let's say we use it for five hours. That will use about 34 of our 120 watt hours, leaving us with 86 watt hours. We'll use some of them to charge a smart phone. A typical battery might have a capacity of 8 watt hours or so and let's assume a couple of people in the family have phones. We now have 70 watt hours remaining. Of course, it could be that we don't use our phone enough to need to charge it every day but, if we have kids and there's internet, we will.

We certainly can't use the energy for heat. While such a use is very efficient (approaching 100%) it's extremely power hungry. Let's figure that our family wants to use a Chromebook or some such to have internet access. The Samsung Chromebook battery features a 30 watt hour battery that lasts 7 hours. If we only use it for 3.5 hours per day we'll use 15 watt hours, leaving us 55 watt hours. We'll assume that the smart phone provides a wifi hotspot so that we don't need a router and some sort of IP service provider.

So, we have a single light on for five hours, two smart phones and a Chromebook and we've used over half of our stored power. We certainly won't be able to pump water, provide heat, charge a vehicle battery, etc. So, while there's no argument that 24 hours of electricity can be provided by pedaling for an hour, it's not the sort of electricity use that a denizen of a developed country thinks of. My family uses electricity at an average rate of about 2,000 watts (we're hogs though), a ratio of about 300:1.

Further, contrary to another Bhargava claim, this is not free. If we figure the human body
Image credit: unknown
operate at 20% efficiency in turning food chemical energy to mechanical energy (I think that this is high, others think that it's low) then these 150 watt hours or about 129 kilocalories (that is, food calories) will require ingesting about 650 kilocalories of food. My suspicion is that a family whose life will be changed by the ability to light a bulb for five hours, charge two phones, and use a Chromebook for 3.5 hours isn't sedentary and thus in need of exercise.

Might there be a use for the pedal powered generator/battery combination? I think that there could well be. But the idea is not original (though this application may be). Bhargava's heart would seem to be in the right place, I don't think he's charlatan. He also has innovations in health care, water purification, and to use graphene cables to draw heat from the Earth's mantle. He also funds and houses other innovators in an incubator fashion. You can't accuse him of not thinking big. In due time, I hope to look at some of his other innovations.

Update: Bhargava is interviewed about some of his innovations at CNBC. He says that the Free Electric hybrid bike can power "24 lightbulbs, a fan, a phone charger, and a tablet." He goes on to say that you can either use it all at once or store it in a battery. On the video linked in the second paragraph, someone working for him states that it can power "1050 equivalent watts of lighting." None of my physics books discusses the unit "equivalent watt" but the video shows 24 lit bulbs. A closeup reveals the labeling on the bulbs. Looking them up, they're 4 watt, 12 volt LED bulbs so we're talking about 96 watts. I'm sure that the "equivalent watt" is the conversion to the luminous intensity of incandescent bulbs. Also shown is a blowing small fan, a tablet with the display appearing to be on, and a smart phone in a charger. I'd estimate the total load of all that at something like 110 or 120 watts and so I'm confident that my discussion above does apply. They show a closeup of a digital meter that is displaying 274 but don't mention 274 of what. I assume that it's watts, and that the peddler was pushing himself at that moment.

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