Latest "Green" Power Generation — Your Feet

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."

Comments

There is no free lunch

[Omniscious]

As well as no free energy.

Re:There is no free lunch

[dougmc]

Energy from the sun is approximately free, especially when you put your solar panels on top of building and such rather than in fields ... but I digress. (I said approximately -- the solar panels are not free, and neither are any other components or their maintenance.)

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.)

Re:There is no free lunch

[FinchWorld]

As well as no free energy.

There is however an amass of energy out there going to waste.

Re:There is no free lunch

[flyingsquid]

6,500 lightbulbs may sound like a lot but if it costs millions...

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 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.

Re:There is no free lunch

[tehdaemon]

Yes, Wikipedia is your friend, but you have to know how to use it. Most solar cells are not cadmium telluride.

From this wikipedia link,

First-generation photovoltaic cells (also known as silicon wafer-based solar cells) are the dominant technology in the commercial production of solar cells, accounting for more than 86% of the terrestrial solar cell market.

T

Re:There is no free lunch

[Deadstick]

Probably something akin to walking up a slight incline.

And that would be bad for the typical obese American or Brit how?

rj

Waste of resources

[jafiwam]

Humans can't power much continuously. At full tilt on an efficient machine a PRO biker can light a 100 watt bulb. The average luser working out, not worth the bother.

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.

freeking obesity epidemic

[Anonymous Coward]

Most western and industrialized nations people need all the extra exercise they can get. (I said most, not all, some people actually stay in shape, most do not, go ahead, look around you) I think the artificial urban power sucking islands could use around a few million of these generators, help to walk off some of that lard and get some practical benefit from it. I already see those ridiculous belching buses that they praise as mass transit stopping every couple hundred of feet. Egads people can't even walk beyond that? Then they go sit on their asses all day long at some office. Jeebus, how wuss can you get? "OMG it feels like walking on sand! I might get the swooning vapors!"

The idea is not as bad as it seems

[ZarathustraDK]

Getting all nerded up and talking about "there is no free energy" only covers it partly, specificly the bad part.

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.