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

Re:Waste of resources

[dougmc]

I may agree that extracting energy from humans like this isn't practical, but your figures are wrong.

A world-class bike sprinter can put out 1500-2000 watts for a short period of time, perhaps a minute or so. Lance Armstrong can put out about 500 watts for 30 minutes or so, 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.

Re:There is no free lunch

[gbjbaanb]

by people walking on them, it will make it harder to walk

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.

Re:There is no free lunch

[sentientbeing]

Youre right.

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/

Re:There is no free lunch

[smaddox]

Also, these wouldn't require the noxious chemicals solar panels are made of, and wouldn't require as much maintenance (I think). Noxious chemicals?

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.

Re:There is no free lunch

[maxume]

Probably:

http://nymag.com/health/features/46213/