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While we're on electric motors and generators
Ninehigh - 5/12/11 at 08:28 PM

My memory threw this at me this morning:

Anyone remember the program on BBC ages ago where a bunch of people powered a house for a family using generators on bikes? The idea was to highlight just how much electric people use, and put it in terms of pedal power.

I'm now wondering if there's such a thing commercially available now, as there's a bike in the garage going unused and a pie-laden body in need of a good few hours pedalling. Surely it's possible to stick that generated electric straight into the mains (maybe through the aid of an inverter) as I doubt I'd ever make enough to actually cover what's being used (I could make sure of that by having the TV on.

Anyone know of anything I could do?

Autosri - 5/12/11 at 08:32 PM

maybe you could use a normal dc motor and and feed that into a solar panel circuit board as you would never be able to generate a perfect 50hz sine wave but the solar panel controller could

blakep82 - 5/12/11 at 08:36 PM

plug a generator in the mains, it'll spin won't it? (as the gubbbins is exactly the same as a motor isn't it?)
motor powers the bike, you sit back, eat pies and watch telly sorted

Ninehigh - 5/12/11 at 08:37 PM

quote:
Originally posted by Autosri
maybe you could use a normal dc motor and and feed that into a solar panel circuit board as you would never be able to generate a perfect 50hz sine wave but the solar panel controller could


That's what I was thinking, I'm looking at something like this that's on a stand so I can just stick the bike on.

mcerd1 - 5/12/11 at 08:39 PM

maybe you could just wire it up to his x-box / playstation (through an inverter) that way it you'd save that little bit of power

big-vee-twin - 5/12/11 at 08:45 PM

You would need to get permission from the electricity board and complete a G59 power export application

Unless of course you just intend to hammer two nails into a bit of wood and use some jump leads to connect it up to the mains and say nowt.

Ninehigh - 5/12/11 at 09:08 PM

I was thinking a bit inbetween those suggestions..

The thing with relying on that power is when I run out of steam and it all falls down, I was thinking if I could plug it into the mains (with a plug and not jump leads!) I could do a low tech version of what would be happening with solar panels.. I mean I doubt I'd be making enough to run a tv I was just hoping I could make a little bit of a difference.

I've found this but with the shipping and power inverter it's way expensive!

skodaman - 5/12/11 at 09:09 PM

You'd be pedalling flat out for an hour to save about 5p though.

Ninehigh - 5/12/11 at 09:31 PM

quote:
Originally posted by skodaman
You'd be pedalling flat out for an hour to save about 5p though.


Lol probably! I'm thinking it's a nice side benefit really, if it's possible for under $1000

matt_claydon - 5/12/11 at 09:51 PM

If you pedal at 500 watts (unlikely, that's nearly a horsepower), go for 2 hours (unlikely), and have a 100% efficient generator (impossible) you'll get 1 kWh, or 10 pence with of energy. In reality you'll be looking at 2p saved for an hours work at best!

Take heed of what the program said - electricity is actually very very cheap (it's just we have an addiction to using rather a lot of it) and it takes an awful lot of human power to make very much!

If you really want to save cash do the pedalling in the lounge and turn the heating off. Like any inefficient machine, we give out much more in heat than we do in useful work!

If you're dead set on the idea, the best thing to do is run some LED lighting off a 12v battery and use the bike to charge it.

Macbeast - 5/12/11 at 11:02 PM

You could save a lot more money by using the bike to cycle to work

Simon - 6/12/11 at 01:09 AM

I recently did a Vo2Max test on a bikemachine as a guinea pig in a Uni of Kent Sports science research project.



Can't remember the exact details but started on something like 200 watts resistance, increasing every 15 secs by 5 watts. I peaked at 13 mins and 393 watts and had absolutely had it - yes, the co2/o2 graph proved I couln't have done another 10 secs.

The following week I did 6 x 6.50 min session on same bikemachine, each at 240 watts and doubt I could have done another.

Now, interesting I felt fairly good after I'd done the 75 miles of London to Brighton Offroad ride a couple of months back.

If I want to get knackered quick, I get on the rollers in the garage for 40 mins (mountain bike)

Good luck, but I doubt you'll power a bulb in the garage for long

ATB

Simon

MikeRJ - 6/12/11 at 08:45 AM

IIRC a reasonably fit person can output about 100Watts for a pretty long period. So say two hours of peddling would give you 0.2kW/h of energy or less than 3p.