Idea that I'm sure is not original but curious all the same.

[darkswordsman17]

So random idea just popped into my head today. Maybe it was all the talk of going green that has been thrown around lately, I don't know. I'm kinda thinking that I really should be getting back to exercising and wishing I had a stationary bike. Well, then I somehow think, what would be even better is if you had an array of batteries, and you set it up so that by riding the stationary bike you would charge/recharge them. This way you'd get some guilt free electricity while getting in better shape.

I immediately assume that its been thought of before, and that there's obviously a reason it isn't more mainstream. I would guess cost for an array of batteries that would offer much power at all could quickly climb into the thousands (thinking electric/hybrid cars) so cost is likely a factor. Probably not the easiest thing to get setup for the non electrical engineers, and tying it into your power grid would likely not be the simplest either. Ok, strirke two. Lastly I'm guessing that it'd take an awful lot of biking to really get much electricity.

Certainly I wouldn't imagine it as a solution to power everything in your home, just certain things, say television and computers. The plus there would be that the stored electricity should offer cleaner power than from the grid (been reading too much about battery power for audio equipment I think).

Now understanding that its not cost effective (how long would it take doing that to make up for the cost of the batteries, which would probably need to be replaced before you saw any return on the investment thereby raising it further), what would it take to implement something like this?

 

[dude8604]

I've thought about this too...you wouldn't need batteries - it could be directly wired into your house current, like people who have solar panels. But yeah, I think the problem is that it really wouldn't produce very much power.

 

[darkswordsman17]

Yeah, I know they make some that you use as a generator to power a TV. My thoughts on the batteries is that this way it would be a culmination effect and that you wouldn't be limited to being able to use the devices just when you were on the bike.

Maybe it'd work at say a good sized gym where there would be a lot of them and so they could be used to power some TVs or something. Really if they could figure out a way to make all the equipment in a gym somehow be able to generate electricity it would make use of otherwise wasted energy. Then you could measure your progress by how much electricity you produced rather than the amount of weight you lifted or distance you ran/biked.

Obviously my head is way in the clouds here, but eh.

 

[arrfep]

Actually I've seen one that somebody rigged up in their own workshop, back in the day on roadbikereview.com or somesuch other cycling forum I used to frequent. Anyway it was just your regular stationary trainer that works for any bike; resistance is created by a freewheel. So this person welded an old car alternator to a frame, and the frame to his trainer. Then he ran a belt from the trainer's freewheel to the alternator. The alternator charged a large batter, just like it would in a car. The batter was attached to an inverter, and voila! free power. Of course, it was only enough to run a lightbulb, or maybe a small tv.

But the cumulative effect might work also, if you rode for a half hour every day, on Sunday maybe you could watch a whole ball-game on the charge.

 

[AgaBoogaBoo]

The energy required to produce the energy for you to charge those batteries is a lot higher than you end up with. This is like getting 10 AA batteries, making them run a motor, which then charges something, resulting in the power of maybe only 1 of those batteries.

The economics behind it might be more important though because power can come from sources like the sun, which don't directly in themselves cost us anything.

The reason this isn't used is because the equipment needed to use it properly is too complicated and expensive for what you want to do. First, how much will your exercise actually produce? Is it enough to warrant even bothering? The simplest comparison is the cost of equipment to set this up, batteries, etc. versus the price at which you can get the power from the power plant at.

What are you going to power? If a TV, unless you want to use it for a short period, turn it off, switch power sources, and then turn it back on, you'll need some kind of equipment to switch inbetween the sources properly, this is adding another cost and layer of complication.

I think that the cost to do all this is more than the benefits, or its just not worth the hassle to do because it's such a small thing. Your idea is a good one though and I compliment you for thinking beyond most people.

 

[AgaBoogaBoo]

Originally posted by: arrfep
Actually I've seen one that somebody rigged up in their own workshop, back in the day on roadbikereview.com or somesuch other cycling forum I used to frequent. Anyway it was just your regular stationary trainer that works for any bike; resistance is created by a freewheel. So this person welded an old car alternator to a frame, and the frame to his trainer. Then he ran a belt from the trainer's freewheel to the alternator. The alternator charged a large batter, just like it would in a car. The batter was attached to an inverter, and voila! free power. Of course, it was only enough to run a lightbulb, or maybe a small tv.

But the cumulative effect might work also, if you rode for a half hour every day, on Sunday maybe you could watch a whole ball-game on the charge.

If he wants to do it to see if he could get it to work as a project of his own or something, I'd encourage that, document everything, take pictures, and run some tests. Post all that on the internet and you'd probably get some interest from people reading about it

 

[PurdueRy]

Theres a number of problems with doing that, such as changing of your pedaling speed. As this changed, the amount of current generated would also change. Charging a battery is a very sensitive process and the amount of current needs to be regulated and monitored. If the battery is not actually charging, you could get the batteries quite hot and they would go the way of Sony batteries.

So the trick comes with how to regulate your current you are generating and keep it within tolerances. Frankly, the amount of components it takes to do this would exceed the reason to charge batteries via manual power.

 

[darkswordsman17]

Yeah. I mean enough to be able to charge up a computer and some other gadgets (cell phones, DAPs, etc.), maybe set it up so its like a UPS or line conditioner for your home. Doesn't have to be anything major but it could make a difference that if it ever became common enough could really add up.

Another idea would be an electric scooter where when you park it at home you could exercise on it to charge it and then when you wanted to go somewhere you just hop on and go. This wouldn't be meant to replace a bicycle but rather say a moped type device. I wouldn't be at all surprised if such a thing is common in say Asia or Europe.

Of course if we had better battery technology it'd help. Then again we'd just figure out a way to harness lightning and not worry about electricity much at all.

 

[darkswordsman17]

Originally posted by: AgaBoogaBoo
The energy required to produce the energy for you to charge those batteries is a lot higher than you end up with. This is like getting 10 AA batteries, making them run a motor, which then charges something, resulting in the power of maybe only 1 of those batteries.

The economics behind it might be more important though because power can come from sources like the sun, which don't directly in themselves cost us anything.

The reason this isn't used is because the equipment needed to use it properly is too complicated and expensive for what you want to do. First, how much will your exercise actually produce? Is it enough to warrant even bothering? The simplest comparison is the cost of equipment to set this up, batteries, etc. versus the price at which you can get the power from the power plant at.

What are you going to power? If a TV, unless you want to use it for a short period, turn it off, switch power sources, and then turn it back on, you'll need some kind of equipment to switch inbetween the sources properly, this is adding another cost and layer of complication.

I think that the cost to do all this is more than the benefits, or its just not worth the hassle to do because it's such a small thing. Your idea is a good one though and I compliment you for thinking beyond most people.

Exactly what I was thinking, just too many shortcomings and it'd take a very long time for it to be cost feasible.

Then there's also the added factor of human laziness. How many people stop using treadmills/stationary bikes after a short while? Of course imagine if you had to exercise to generate the electricity needed to say power an electric water heater or a refrigerator, or maybe for cleaning like a roomba robotvac. That might get people to stick with it. Just poking fun as obviously that wouldn't catch on (even I would be angry about it).

 

[darkswordsman17]

Originally posted by: AgaBoogaBoo

If he wants to do it to see if he could get it to work as a project of his own or something, I'd encourage that, document everything, take pictures, and run some tests. Post all that on the internet and you'd probably get some interest from people reading about it

That would be fun. Unfortunately doubtful that I'd ever do it, but maybe something to add to the look into if you're bored type things.

I think it would make a great science project for say a high school.

Really, with the combined knowledge and capability of ATOT (er, maybe not after all ), this might be something to do.

I wouldn't mind setting something like that up if for no other reason than for cleaner power for say audio or computer setups. Hey, that'd be a way, fund your SETI/Folding by keeping in shape.

It'd be great to get projects that AT members could work together on. Plenty of things to learn and hey, why not nef for a good cause?

 

[FoBoT]

the amount of electricity you would generate is negligible compared to you total usage, it would be a waste of effort