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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."
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.
I would think that piezo-electric mats that absorb sound would create more energy while at the same time reducing the amount of noise would be more practical than collecting potential energy from passing trains.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
This sounds as practical as trying to harness the 'incredible power' of our stomach acid for energy generation. I'm sure we could power a lot of lightbulbs in a lot of ways - but I think there are better options than relying on extracted energy from human movement. It's like relying on whale and pig fat as a major power source - it just doesn't scale past a small market segment.
What we want is to use something more scalable, like algae-based oils, 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
Take a door in a public place. There's a hydraulic mechanism to make sure it doesn't slam shut. There's a bit of a resistance when you open a door. Think of how many times doors in public places open & close on a given day. Sure, it may not be much per 1 door open/shut, but imagine a shopping mall or office with hundreds of doors.
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.........
W=f*d
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.
Can you be Even More Awesome?!
This was brought up in the media last year from the folks at MIT: http://archive.uwire.com/2007/09/11/mit-students-take-step-toward-cleaner-greener-urban-energy/ In fact, I could have sworn I saw the story run here on Slashdot. Can't we just reference the arguments from then so we don't have to rehash them?
It seems that stepping on a tile with pads which push fluid through turbines would have kind of a gel effect or feeling to the people walking on them. This could reduce the impact on the joints and perhaps the fatigue of walking around.