Pedgens may not produce large amounts of power, but their power savings is significant, especially in cooler weather with space and water heating taking the biggest cuts in demand. In cooler weather no energy seems to go to waste; even the heat generated by the generator (perm-mag motor) and charge controllers is dissipated into the room. I've been using mine for a year now, and it's done a lot for me, both in health as well as power savings (average electric bill down by 500 kwh/month; 10 lbs gone and total cholesterol down from 240 to 189).
Granted, some of that savings came from other spots, especially the $100 worth of caulk, weatherstripping & urethane foam that sealed up the holes in the concrete around the dryer outlet, the sump pump outlet, etc. etc...but I'm sure the bike did its part.
Even with several inefficient safeguards in place, such as a charge controller and batteries (to protect the inverter) an average 60-watt avg power output is generated during a 30 minute workout (so 30 watt-hours generated; more generated during a quick 3-minute sprint, of course). A simple 5 minute warm-up in a 50-degree room can produce 5 watt-hours, and the baseboard heat stays off. I've been comfortable even in a 37 degree F room after about 10 minutes of pedaling in shorts.
One problem; the grid-tie inverter tends to take more and more from the pedgen until it "maxes out" at 200 watt demand. This repeatedly causes a "crash" and reset back to zero, since I cannot constantly supply such a "large" amount of power. It also causes a lot of stress on my legs, and I've had both a sore achilles tendon as well as a tender ACL due to the repeated stress of 'sprinting'. Anyone know of 80 watt or 100 watt 60hz grid-tie inverters out there?
Thanks,
Dan
PS These are also fun to crank, but usually I just try to let them charge in the sunlight: http://www.amazon.com/FR160B-Microlink-Self-Powered-Weather-Flashlight/dp/B001QTXKB0/ref=sr_1_cc_2?ie=UTF8&qid=1288155868&sr=1-2-catcorr