Capturing Energy from Walking?

[M.D. Holloway]

Read an interesting article today on capturing 'footfall' energy...

" British engineers are converting street vibrations into electricity and predict a working prototype by Christmas capable of powering facility lights in the busiest areas of a city.

"We can harvest between 5 to 7 watts of energy per footstep that is currently being wasted into the ground," says Claire Price, director of The Facility Architects, the British firm heading up the Pacesetters Project. "And a passing train can generate very useful energy to run signaling or to power lights."

Like solar and wind proponents, vibration harvesters argue that abundant, clean energy is all around us and goes to waste. The challenge is how to store the power efficiently so it provides a continual output even if the vibrations from footsteps or passing trains temporarily taper off.

Price has charged Jim Gilbert, an engineering lecturer at the University of Hull, with developing the prototype system for capturing footfall. Gilbert is working with hydraulic-powered heel-strike generators, which he believes could be installed in the floors of busy public places like subway stations. Those stations typically capture the footfall of 20,000 commuters an hour during peak usage -- multiplied by 5 to 7 watts a person, that's more than enough to power a building's lights for the day.

Price, for instance, tried to develop a heel-strike generator for soldiers' boots -- the issues of dirt and water proved overwhelming. Putting the generators in the floor inside of buildings would eliminate many of those challenges, though. Price notes that such developments could save billions in costs related to digging and installation currently required for street lights and other such applications. Seems to me that, at least in urban areas (where I guess this would be most practical), this would also provide the most energy at times when its really needed -- the evening commute, for instance. Here in the US, couldn't you see such a generator working well at, say, the mall or grocery store on Saturdays? I'll definitely try to keep an eye on this one -- very intriguing!"

more info on http://sustainablog.blogspot.com/2006/08/brits-researching-footfall-energy.html

Combine this with solar, wind, hydro and nukes and better conservation methods and maybe, just maybe we can become a little less enslaved by crude oil.

[Rich76_911s]

I sit around and think about crazy alternative energy ideas too frequently. Like putting wind generators along highways so when trucks and cars pass by the energy can be garnered and used. I've thought about mini solar and wind powered water splitting devices to create hydrogen to use for small daily commutes with a hydrogen powered car. My ideas are just stupid little things I try to think about where energy is wasted. I was thinking about designing a refrigerator that used a fan and pushed cold air in from outside during times when the outside temperature is low enough to cool the fridge instead of using energy. I wish I had the educational background to work in this field.

One thing I don't get about the walking thing is that I would have thought that the majority of wasted energy in stepping would be absorbed by your nikes not the ground. Are you stepping on something that compresses and uses the energy from the compression to create electricity?

[john70t]

It's a system of physioelectric pulse generators, mabye with quartz crystals. When there's a vibration, a weak voltage pulse is created. Combind enough of them and a usable voltage can be created.
There are some neat clothing designs out there with communications/lights/etc.. built into them and powered by generators in the shoes. All experimental now.
Initial cost, maintinance, and cost savings are factors in viability.

[M.D. Holloway]

Exactly! Piezoelectric microgenerator devices are composites that convert mechanical energy into electricity. Piezoelectric devices originally took current and convert it into mechanical energy much like the way muscles convert electrical impulses into movement. The problem is that of efficiency and durability though there has many improvements over the past several years.

Another method is hydraulics. I do not know a whole lot about that sort of energy generation method.

[BlueSkyJaunte]

Excellent, I'm going to put on 100lbs and start back-charging the Limeys for the energy they're stealing from my feet...

[Superman]

Now that's innovative thinking. Lots of guys here to tell you what can't be done and poke fun at stuff that's not on the market yet, as though folks are silly to use their imaginations........but these kinds if ideas are going to get us the breakthroughs we need. I still think we should hook generators up to the stationary bicycles at the health spa. Those folks might as well be doing something productive. Later this week, I get to split some firewood. I always loved doing that.

[pwd72s]

Put sugar high kids in giant squirrel cages. Hook up generators...
Energy crisis solved.

[notfarnow]

Originally posted by pwd72s
Put sugar high kids in giant squirrel cages. Hook up generators...
Energy crisis solved.

Sounds funny, but I've thought the same thing... more like Superman's idea of stationary bikes hooked up to a generator, hooked up to a battery w/inverter.

Have the TV, nintendo etc. wired to the battery. Wanna watch TV or play video games? You gotta get on the bike first and charge the battery.

I think every kid with a TV, comuter or xbox should have this setup... I know mine will. (no kids yet)

[motion]

I still can't believe cars still have disc/drum brakes. That's just nuts. Surely that inertia can be used more effectively than wearing out pads and rotors.

Why aren't houses and buildings run off solar panel roofs?

Change does happen slowly.

[Z-man]

Re: Stationary bikes - why not harness the energy of all those health nuts at the gyms? We could probably light a city like New York with all the pedaling going on!

Re: Solar panel roofs - I believe you'll see this come into play more and more in the next couple of years. The biggest problem is that in many cases, like in the Norhteast, there isn't enough energy captured by a solar panel setup to offset the cost of installation. To install a solar panel system in a typical house runs somewhere from $30k to $40k, before government cuts and such.

Actually, the solar panel setup works quite well - during the day, when the homeowner isn't home, and electricity isn't being used, the homeowner's electric meter will actually spin backwards - since his solar panels are actually feeding the grid. At night, his meter will spin the correct way. If the homeowner is an efficient person, he will wind up paying close to $0.00 for electricity for a year. If I got such a system in my house, I figure it would take about 15 years before I'm have any net gain, which is typical. (But if you start looking into government grants, and private company funding, the initial cost will go down quite significantly.)

Yes, I've looked into the solar panel alternative.

-Z-man.

[red-beard]

At the present price levels, the solar cells do not justify the investment. Regenerative breaking is used on the hybrid cars. On a standard car, what would you do with the regenerated electricity? Recharge the battery?

[Nathans_Dad]

Solar energy is going to be getting much bigger. A couple weeks ago on the radio they had a guy who was one of the leaders in solar technology and he said that in the next 5-10 years you will have solar films which can be applied to standard roofs and could supply energy for water heaters and such. They are also going to be coming out with roof shingles have have solar films embedded in them, same idea. The big photovoltaic panels will be a thing of the past.

[gaijindabe]

Crazy to think how much energy hits the earth every day. We would need to harness like 1% of 1%.

All that heat in summer - all that cold in winter. Got to be a way to store it...

[M.D. Holloway]

Originally posted by notfarnow
Sounds funny, but I've thought the same thing... more like Superman's idea of stationary bikes hooked up to a generator, hooked up to a battery w/inverter.

Have the TV, nintendo etc. wired to the battery. Wanna watch TV or play video games? You gotta get on the bike first and charge the battery.

I think every kid with a TV, comuter or xbox should have this setup... I know mine will. (no kids yet)

I'm not so sure you could generate enough watts. Figuer that 1hp (that horse power not the printers) is roughly 1000 watts - rough seat-of-the-pants figuering. Take away for frictional los and all that, and you might see 800Watts.

Most people would be lucky to be able to generate 1/8 hp. Thats not alot of power. And it would not be sustained either.

The trick would be to hook it up to a battery and store the juice.

[notfarnow]

Originally posted by LubeMaster77
...The trick would be to hook it up to a battery and store the juice.

Read through it again... that's what I said

Otherwise, it'd be hard to play an xbox and pedal at the same time!

[legion]

The fundamental problem with alternative energy is that currently, all of the technologies are more expensive to use than the "conventional" methods.

People will continue to let their wallets guide them.

[john70t]

Some of the larger tranportation vehicles have been in need of efficiency upgrade for a while.

There are some articles (in pop mech/sci?) of the cargo freighters using massive wind sails/kite on a leg of the trip to take advantage of the constant trade winds, and I think Ford might incorporate a regenerative hydraulic system for their big trucks in start-stop situations.

Really old ideas that the big companies are scrambling for, now that fuel will be on the rise.

[john70t]

A few years ago I filed for a patent on a triple-rotor electric motor that I thought up back in '98 (instantaneously when I was dead tired and surrounded by mountains of semi-crushed boxes at the old career), but a guy from Taiwan got there first (strangely.....it was not discovered from my own and a professional search, and the attempt cost me quite a bit of (car)money).
Reference USPTO 6,297,575 for something similar to mine.
The concept was theoretically based on a mass/flywheel/rotor accelerating off one adjoining rotor and decellerating on another, which is reverse geared to the first.
-The motor should have had greater efficiency because the floating reaction points, and a much higher electrical overload threshhold.
-The energy used for acceleration is recaptured by the decelleration-yet both output torque towards the same shaft and the process is reversable depending on rpms. Efficiency being lost with higher rpms.
-The heavy customizable middle mass would also be able to be suddenly decellerate on either rotor, with a quantifying pneumatic effect, or output excess inertia to a seperate electric/pneumatic/hydraulic PTO.


My point is that the next generation of technowlogy is usually based on the previous technowlegy, unless you consider Nickolai Tesla, of course, who pretty-much singlehandedly created our entire modern society from scratch.
But it is free-thinkers and dreamers that fill in the gaps, and reshape the circles and squares, and find the next object and (with enough random banging on something) find a new use for it.

[sammyg2]

Rich, funny you should mention that refrigerator thing.
A couple of days ago I was starting at my fridge. It cools the coils by blowing air over them. The air gets hot, and transfers the heat to the room. That's OK in the winter but in the summer it adds more heat that the air conditioner has to get rid of. In the winter we could save electricity by using colder outside air to cool the coils as you said. Basically a heat pump hooked up to the fridge. It would be a universal unit built into the house just like a central air conditioner unit and the fridge would basically just plug into it. If you wanted to get fancy you could even bury the coils underground where it is cooler and reduce or eliminate the need for a fan, more energy savings. It would save room under and behind the fridge which would allow more storage space for the save outside space.
The initial investment would be high but it should last for a long time. It would reduce the cost of a fridge a little and reduce the cost of running it, so it would pay for itself after a number of years, not to mention it would be more ecologically responsible (did I say that?)

I figure it's only a matter of time before we have these, just remember you heard it here first or second or third.