Tables listed for riding a bicycle on level ground at 10 mph varies for your weight, but assuming you weigh maybe 150 lbs, then you would burn 188 calories. Since the bike, generator, and thermal calories are all hard to accurately convert due to a lot of factors, including ineffeciency, the best numbers one could come up with are perfect numbers if everything was ideal circumstances. 1 Calorie can be roughly equivalent to 0.00000116 KwH, so 188 Calories would be 0.00021808 KwH. My electric bill charges about $.061 per KwH, so .061 X .00021808 = 0.00001330288 $$$ You would have to ride for 75 thousand hours to make about $1.

A slight mistake here in order of magnitude. When we usually talk about "calories" with food or exercise, it's really kCal, so you're off by a factor of 1000 in your calories to kwh conversion. So instead, it's 75 hours.

A VERY rough estimate: a well-trained person may have an output of a few ten to maximum 100Watt ( I did a cardio once where I had to cycle at 60Watt for some time). Let's assume 100W and 100% efficiency. So that would be 1kWh for ten hours cycling. You see, even the most menial task is paid much better!

Well I must be very well trained because I can sustain 250 watts for an hour. That's actual work output, not the energy my body spends, which is maybe 4 or 5 times as much. I can practically fall asleep putting out a mere 100 watts though I'm not QUITE that comfortable. I can only keep up 700 watts for about 30 seconds, and 1300 watts is my absolute limit, for about 10 seconds. The real issue is watts, not speed. However many watts 10 miles an hour amounts to depends on the torque it is set to. That said, going for distance, say, 180 watts for 4 hours is not even a whole kilowatt-hour. About 8 or 10 cents for all my effort. So you'll make 2 cents an hour and quadruple your grocery bills. Great. Unless you get your energy by drinking liquefied propane, maybe. Frankly I don't like the stuff. It's too cold and it smells and tastes really bad. And it gives me really bad gas. Or maybe if you're a serial killer, you don't pay for groceries, you just go out and find another victim. There's a real moneysaving idea. You WILL, however, save LOADS of money on a secondary effect of this - the HEATING of your place of residence. If you actually do this, I guarantee you will not be able to tolerate having the temperature set to anything normal, like say, 72, for very long. Or at least, you WILL be able to tolerate it being 50. Of course, to do this, there is no point to connecting your bike to a generator and feeding it into the power lines. This would be bad for you especially since the power company only will give you a tiny fraction - like 20 cents on the dollar - for energy returned to their grid. So every joule of energy spent being put back into the power grid would probably just be better spent ending up as 'waste' heat in your residence, rather than getting that joule of heat from the power line which will cost you 5 times more right back. If you were stingy, you could save some money on heating in this manner, but I'm afraid unless you're from the planet Krypton (or Vegeta, or your favorite fictional place superheroes come from), this isn't going to be much of a moneymaker for you. Just a money saver. But then, a penny saved is a penny earned. The question is, does the savings match the increased grocery expenditures? And even if it does, is it WORTH the effort and cost to your body? And don't kid yourself. It would NOT be good for you. Hmmmmm. I think not.

The realities of your situation make no difference at all. Doing your part to postpone global warming is a moral issue. So hook up that bike and pedal for all you are worth. It is the thought that counts!

You probably won't be able to make enough money that it's worth hooking up to the grid. However, you can produce enough that it might be worth it to you personally. The average rider can generate around 75-150 Watts while riding at a moderate pace. Connected to batteries and pedaling for an hour a day or so you could get quite a bit of use out of it. You can read more including exact formulas that will show you how much energy will be produced here: http://renewable-energy-future.com/do-it-yourself/bike-generator.php

It would not make much of a difference. Maybe invest in some solar panels?