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Latest "Green" Power Generation — Your Feet
Posted by
timothy
on Sun Jun 08, 2008 02:23 PM
from the my-feet-could-power-gas-generators dept.
from the my-feet-could-power-gas-generators dept.
gbjbaanb writes "Remember those ideas that suggested hooking gym machines to the power grid? Well, the Times is reporting that something like this to harness free energy is about to become a reality — the footfall of trudging shoppers is to become the latest source of emission-free energy.
'Engineers who have modelled the effects of the technology at Victoria Underground station in central London have calculated that the 34,000 travellers passing through every hour could power 6,500 lightbulbs. ... The plans for heel-strike generation follow successful trials last year at a bridge in the Midlands where generators converted energy from trains passing above into electricity powering a flood detector.'
Possibly the most important thing for the readership is at the end:
'There could also be a range of domestic uses, for example powering iPods by plugging them into batteries placed in the owners' heels, using technology which is already available.' Obviously you'd have to get up and walk around, but, as they say, it's the thought that counts."
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There is no free lunch (Score:5, Insightful)
Re:There is no free lunch (Score:5, Insightful)
But as for free energy -- this is not it. By putting generators in the ground that are moved by people walking on them, it will make it harder to walk. I don't know the specifics, but I'm guessing that parts of the floor will move up and down a little as people walk on it, probably a few milimeters. It might be somewhat akin to walking on sand -- and I have to wonder what it would do to a wheelchair.
This might be practical if you're in a remote location where electrical power is unavailable and you only need a little -- but beyond that, the solution seems worse than the problem. (And really, solar power is more practical for remote areas where you need only a little power.)
Parent
Re:There is no free lunch (Score:5, Informative)
I remember some adverts for training shoes that had fluid capsules inside them to reduce stresses on your joints (or something, probably just marketing). People bought them but didn't complain they were difficult to walk in. If the generation systems are of the same order, then I can't see a problem.
I imagine it would cost a fair bit to install, but there's paths everywhere, whereas solar panels have a limited amount of area they can be installed on. Also, these wouldn't require the noxious chemicals solar panels are made of, and wouldn't require as much maintenance (I think).
For other areas, I thought bridges etc had to have soem 'squidginess' to them, or the traffic riding on them would quickly shake it to bits. As the article said, this principle also applies to antennas that wave in the wind, so its not just going to be used in every pavement in the world.
Parent
Re:There is no free lunch (Score:5, Informative)
Silicon, and trace amounts of boron and phosphorous are noxious? You need to go back to chemistry class. Not only is silicon one of the most abundant elements on earth, it is one of the least harmful to humans.
Also, solar cells don't really require maintenance. You would want to clean them occasionally to get optimal power, but that involves spraying them off with a hose. That is the beauty of photovoltaics - there are no moving parts to break.
Parent
Re:There is no free lunch (Score:4, Informative)
IIRC it was cadmium used in the manufacture that made solar cells not as green as they could be.
A quick google says
However there are many environmentalists and some scientists that are worried about the potential negative impact of solar cells (photovoltaic technology). This is because manufacturing process of photovoltaic cells needs toxic metals such as mercury, lead and cadmium
Still, I think its better than coal-fired power, but don't think any green energy generation is the perfect answer to all problems.
Parent
Re:There is no free lunch (Score:4, Insightful)
Yes, Wikipedia is your friend [wikipedia.org], but you have to know how to use it. Most solar cells are not cadmium telluride.
From this wikipedia link,
T
Parent
Re: (Score:3, Funny)
Re:There is no free lunch (Score:4, Informative)
What they found is that your body is used to a certain 'feel' from the ground when you walk. It turns out that more cushioning = more stress on your joints, because your body notices the lack of pressure & compensates with harder heel strikes.
The article tied all this into walking barefoot and some shoes that were about as close to walking barefoot as you can get.
Anyways, the moral of the story is that you do work harder with cushioned shoes and they're not good for the health of your feet & lower joints.
Parent
Re:There is no free lunch (Score:4, Informative)
http://nymag.com/health/features/46213/ [nymag.com]
Parent
Re:There is no free lunch (Score:4, Interesting)
In the case of the shoes, work done compressing the cushion approximately come back on the up-stroke. It's fairly conservative (in the physics sense). You'll find that if the shoes had tiny holes in the cushions, it'd be quite a bit harder to walk in them, especially if they had a lot of vertical play. The difference between a spring and a shock absorber.
Parent
Re: (Score:3, Insightful)
Re:There is no free lunch (Score:4, Insightful)
And that would be bad for the typical obese American or Brit how?
rj
Parent
freeking obesity epidemic (Score:4, Insightful)
Parent
Re:There is no free lunch (Score:5, Informative)
I remember this being debunked using basic energy estimates and calculations last year by The Register.
http://www.theregister.co.uk/2007/07/30/all_the_power_they_would_ever_need/ [theregister.co.uk]
Parent
Re: (Score:3, Insightful)
Re: (Score:3, Insightful)
Re:There is no free lunch (Score:4, Insightful)
6500 light bulbs isn't all that much. Let's be generous and say that each bulb is a high-powered, inefficient 100-watt incandescent bulbs. 6500 bulbs x 100 watts = 650,000 watts, or .65 megawatts. To put things in perspective, a coal or nuclear plant might put out 500-1500 megawatts of power (according to various Wikipedia pages). Obviously, the power output is going to be a lot lower if they're talking about 15 watt compact fluorescent bulbs, however; that'd be about 100 kilowatts of power. That's a respectable amount of power, but you've got to ask (1) how expensive is it going to be, (2) how widely applicable is this model going to be, and (3) how reliable is this power source? Presumably foot traffic is going to decline substantially at night, and perhaps on weekends and major holidays, so the average power generation will be much lower than peak power generation.
I thought this article http://www.npr.org/templates/story/story.php?storyId=90714692 [npr.org] provided a much more practical take on the problem. Apparently, factories, mills and refineries which generate high temperature exhaust can use that exhaust to generate power. A major difficulty here is legislative, not technological; if you install the machinery to generate power from the heat produced by a steel furnace, laws designed to protect utilities mean that it's often difficult to sell it.
That being said, I don't think that recycling waste heat, or any other single technology will solve our energy problems. We need a whole suite of technologies- the ability to drill for deeper oil deposits, more cost-effective mining of tar sands and oil shales, more efficient cars, solar, wind, and more efficient houses, cars, and light bulbs- to increase our supply and reduce our demand.
Parent
Re:There is no free lunch (Score:4, Interesting)
Exactly. This article completely ignores the most interesting question -- is it cheaper or more expensive than other zero-emissions sources of energy, like solar? In some specialized applications, human power is nice. But in a supermarket or train station, power is readily available, and this should be compared on even footing in terms of $ per watt of generation capability against other options. Somehow I doubt it beats out solar power. Sure, it may be (*) cleaner than fossil fuels, but what's the point if it costs more than solar?
* Depends whether you count the marginal fossil fuel cost of food calories, which are a very expensive form of energy by the time they reach your plate. There are reasonable arguments both ways.
Parent
Re:There is no free lunch (Score:5, Funny)
Parent
Re:There is no free lunch (Score:5, Insightful)
There is however an amass of energy out there going to waste.
Parent
Re:There is no free lunch (Score:4, Funny)
Parent
but there is easy energy (Score:3, Interesting)
At the moment all he does is operate the flywheel while he plays (a little noisy, but better for his legs then just sitting static for ages). I want to set it up with a generator so we can use it to power something, or store the charge in a battery.
Not perhaps the most efficient means of power generation, but a teensy bit cool.
Waste of resources (Score:5, Insightful)
All the equipment, moving parts, maintained, used to capture human power won't reach the point of break even on any of this stuff. (If you pay your maintenance guy at least.)
They'd be better off CLOSING the stinking gyms and making people work out outside and not DRIVE there than capturing that power.
Green is not complicated, often, it is SIMPLE.
Re: (Score:2, Interesting)
Re:Waste of resources (Score:5, Informative)
A world-class bike sprinter can put out 1500-2000 watts for a short period of time, perhaps a minute or so [wikipedia.org]. Lance Armstrong can put out about 500 watts for 30 minutes or so [pezcyclingnews.com], and a somewhat lesser amount for many hours.
I'm a pretty weak pedaler, but I can put out about 100 watts for an hour or so without too much trouble.
Parent
Re: (Score:2, Insightful)
Not green energy (Score:5, Funny)
Re:Not green energy (Score:5, Funny)
yeah, we should ban humans and all the world's energy problems would be over.
Parent
Re: (Score:2, Insightful)
Post was modded "Funny", but it's actually true. Wish there was a +1 "Ironic". I would hazard a guess that most of the World's problems wouldn't exist w/o people...
Dunno about this... (Score:2)
who writes these articles? (Score:5, Funny)
GREAT ! If it's the thought that counts why do I have to get up and walk around??..I could only imagine that I'm walking around and watch those batteries juice up....
Emission free? (Score:5, Funny)
Hmm, it's getting dark in here. (Score:2)
Cool toy, but... (Score:5, Interesting)
What we want is to use something more scalable, like algae-based oils [wikipedia.org], using arid and other unfarmable land, and not using fresh water sources for production. That, plus increases in solar power efficiency are much more direct ways of gathering usable energy, which could scale far beyond our current needs in a sustainable way. That way, we raise the standard of living of people by increasing energy production, rather than make them stick battery chargers on their feet.
Ultimately, food and fresh water will be bigger concerns going forward - and I don't think we'll be able to grow sustainable crops in our shoes with any toys either.
Ryan Fenton
Re:Cool toy, but... (Score:4, Interesting)
Exactly. Why would we want to rely on an unpredictable, complicated solution to generate a small amount of electricity when we could be harnessing lots of other sources which are much more reliable, scalable, simple, and cheap!
What about using EM induction to slow down trains? How much electricity could a freight train generate if it stopped using a "third rail" and some magnets beginning a few miles out of town (when it'll already begin slowing down). The savings in mech braking wear and tear, the usefulness of the quantity of electricity generated, the predictability, reliability, simplicity, and cost of such a system make this idea seem so much better than trying to harness the power of "walking."
But we're not into "useful tech", we want something "clever" sounding and "outside of the box" - even if it's really useless and a waste of resources that could equivocally produce a superior, albeit "boring" and "obvious" solution.
This green revolution made so much more sense when it didn't have the all the hype. Bring back the old timers!
Parent
Re: (Score:3, Insightful)
Well, that depends on how you define the Green Revolution [wikipedia.org]. I prefer to define it in terms of agriculture and human production standards. In terms of the work of Norman Borlaug [wikipedia.org] and other scientists' contribution, rather than as a way to dismiss folks as leftist, which these folks in particular are not. That work has likely saved the lives of more people than almost any other act in human history.
T
My feet are always green energy (Score:2, Flamebait)
Maybe the tap-dancing grifter (Score:2)
The idea is not as bad as it seems (Score:4, Insightful)
In 'reality' though there are certain bonusses to a soft walking surface.
1. You get more traction and reduce slipping of feet (which is a problem on hard surfaces with grains of sand on it).
2. Damage from falling is reduced.
3. A soft surface is easier on the joints, which is important for everyone, though especially elderly and disabled people.
Try finding one of those new fancy playgrounds with a semi-soft rubbery-like surface and walk on it. Much more comfortable to walk on compared to concrete.
How about harness doors? (Score:5, Interesting)
Take the hydraulic damper and turn it into a generator. Chain together all the doors and have it provide power peak power hours(when the public will be using them). Make them compatible(ie mount-wise) with existing dampers & retrofit them everywhere.
Slap a generator on those revolving doors too. Imagine the power it could make in a busy downtown area.
Dang, I should patent this before.........
Re:How about harness doors? (Score:4, Informative)
Parent
Even better... (Score:3, Funny)
What we really need (Score:3, Funny)
But who owns it? (Score:3, Interesting)
Old news (Score:3, Interesting)
Additional Benefits (Score:3, Interesting)
The green broken window fallacy (Score:3, Interesting)
Here's something I've been wondering ever since I found out my body could generate peaks of 400 Watts at the gym. Is human energy really green?
My analogy to the broken window fallacy is based on the fact that this fallacy relies on what we see (the store owner buying services from the glazier) versus what we don't see (the store owner not investing that money for better purposes). Note that the logic also holds for alternative energies such as electric cars (which electricity comes from coal power) or ethanol which has to be processed/transported in a polluting way. So how green is human power? Considered that what powers us is food, we have to look at how much energy is involved in the making (making that cow live, eat and die involves making its food, transportation, etc..), the transformation and the transportation (a lot of the food you eat has travelled thousands of miles). Also it's important to note that just because it's necessary for us to eat food anyways, it doesn't make our energy free. You'll need more food if you produce 100 Watts for 30 minutes (say, if you're jogging) than if you just lay there.
Unfortunately I'm not qualified to estimate how polluting human power actually is, but I'm sure it's far less greener and more expensive than most people would assume. I think it's just yet another of these "feel good" measures that are actually not that good at all. When will we realise that there's no problem that can't be fixed by throwing a few trillion dollars into nuclear power and r&d?
Re:success to-date sounds limited (Score:4, Interesting)
Parent
Re: (Score:2)
*guitar riff* *guitar riff* *(Ding! Turn left in 300m)*
What you're forgetting is ... (Score:3, Insightful)