What equipment would be necessary to generate power using a stationary bike, a generator, and some storage batteries. Let’s say I wanted to generate enough power to run a TV that consumes 120 watts. How long/fast would I have to pedal to keep it running? How about charging up several 12-volt car batteries (assuming I have a voltage converter) and using the energy to run said tv (or any other appliance)?
Some good info here:
Some quotes:
If you’re looking for homebrew power, but not specifically human musclepower, one of the best plans I saw (and this takes a bit of implementation) was to build an elevated reservoir or water tower, to use wind-driven pumps to fill it and use the water (and gravity) to drive a water-wheel or turbine.
Hasn’t your city already built the water tower for you? Seems that normal water pressure would be enough to run a turbine. 'Course, the turbine’d only run while you’re using water.
Hey great sites arjuna.
Back in the olden days it was the job of an apprentice ,usually a boy,to turn “the great wheel”. Depending on the type of shop the smith had it would turn different tools,through the use of belts,pulleys etc.Drills lathes etc.
Sometimes he would just walk inside the wheel Sometimes a crank was all that was needed.
I wonder if the experimenters have gone beyond their “portable” models and put their bikes on or in a "great wheel?
Waaay back in the 1970’s, I remember a Real People show which had a segment on a family who pedalled to run their TV. Anyone know if there’s a Real People archive online?
As an idea of how hard it is to produce power for humans then consider that professional cyclists can churn out around 400Watts for maybe the length of a time trial, around an hour and then they are finished.
Mere club riders such as myself might be able to kick out 200-250Watts over the same period, for those not used to riding and racing I would imagine that 120Watts would be at their limit.
If that does not seem impressive then remember that 746Watts=1 horsepower, top cycling sprinters can kick out that much and more over a very short period.
This works out well with what I learned during my electrical apprenticeship-- A human can generate 1 horsepower for a brief (few seconds)time, and is good for about 1/4 continuous horsepower.
What about a hand cranked generator like the free play radios for laptops. I envision a small powepack the size of a book with an unwinding spring powering a generator. The powerpack could be plugged into the laptop once it was would up. Is this a practical invention? How much power does a laptop computer consume in say 4 hours? The standard computer battery is about the size of a pack of cigarettes I can’t believe a good cranking for two or three minutes would put out less power that that battery.
Well, yes, and in fact my water is unmetered, but I think the water company would get a bit mad if they found out I was running clean tapwater down the drain just to run a turbine.
The plan I saw involved two reservoirs, one much higher than the other; wind driven pumps carried the water from the lower one to the higher one and it would do work on the way back; it was really just a way of storing the wind power so that it could be used on demand, not just when the wind is blowing.
Mangetout wrote:
Hmmm. Mrs. W. and I are planning on finding some land for a home, with a stream on it. I was daydreaming about building a dam for a swimming hole when my daydream suddenly included a turbine powering a radio and/or lights around the place. Need a much bigger dam, which was fine by me, but then a friend said that not only would my downstream neighbors not feel good about it, but the EPA would probably come after me. Yikes. So, my daydreams have turned to windmills.
The windmill-pumping-water-into-a-resevoir is an interesting idea, but… A couple of things occured to me. One is that in case of storms, one would want to disconnect the windmill from the pump. This will allow the windmill to turn freely (no load), which I believe will minimize damage to it. It’ll also prevent damage to the pump itself. Secondly, one would want some sort of mechanism whereby if the resevoir becomes full, the pump won’t run, which will prevent overflow and, again, damage to the pump.
So, it seems to me the easiest way to do these two things would be to have the windmill crank a generator, which would power an electric pump. A master switch will allow you to turn the pump off in nasty weather, and a level-sensing switch in the resevoir could turn the pump off when it becomes full.
In this arrangement, the resevoir is acting as a big storage battery. So, why not do away with it, and the pump, and just get a bunch of big truck batteries, and use the windmill to charge them and keep them charged? Save an awful lot of hassles of getting a permit for, and construction, of a water tower. Putting up the windmill itself would be enough of a pain.
I guess I’m just wondering if there is any real benefit to having the resevoir. I suppose if there weren’t any batteries to be found, or if all you want to drive are mechanical things, and have no electric motors, then it’d be a good idea…
The vane on the back side of a windmill has a dual purpose. 1st to keep the propellor into the wind.
2nd when the vane is tripped it takes the prop out out of the wind and it shuts down the rotation so nothing is damaged in heavy winds.
3rd Hi Opal
the vane is spring loaded so when the wind is too strong or the tank is full it is just tripped which puts the vane and the blades in the same plane.The vane is still into the wind but the prop isn’t.
Yes, the idea that I saw was concieved primarily as a method of storing mechanical power from wind, this could be used to drive machinery directly, thus avoiding the loss through inefficiency when you convert from mechanical to electrical and back again.
I’m not sure how it would deal with the storm scenario, but I expect it’s possible to design a wind turbine that is invulnerable to anything short of a tornado.
As regards the cutoff when the top reservoir is full; if you’re using a mechanical pump driven directly by the windmill, there’s no point in shutting it off (except to prevent minimal mechanical wear maybe), you just let the top reservoir overflow down a channel back to the bottom.
Here is a website for people that are of the same mindset as you are.It is sponsored by Lehmans.
Here
there are lots of others on the net
Here=
http://www.countrylife.net/servlets/sfs?t=messageOverview&i=953568555281&b=953568555281&c=Default&l=0&customerID=guest&FormID=959192659250
If that don’t get you there try (thecountrylife.com). Go to"Off the grid"
You know what’s weird, I don’t remember hitting the ‘submit’ button - in fact, I had to get offline quick, and closed the “reply to topic” window unceremoniously, thinking it was no big loss. And while offline, I decided that post was far too long-winded and, well, crappy. But…
Interesting note on the vane, justwannano, thanks. I imagine that the vane just snaps 90 degrees to one side? By the way, neither of those links worked for me, some sort of Java error.
Overflow pipe. Duh. I was right in thinking that post was crappy, Mangetout (the other main reason being that it’s straying rather far from the OP).
OK try this
http://www.The New Countrylife.net
Follow the path titled ( select discussions ) and then ( Off Grid Power ).
I don’t usually have this much trouble
You could also just collect rainwater in cisterns on the roof, and then let that flow out to do work.
Let the water cycle do the lifting work for you.