As for using a bicycle as a PTO device, imagine being asked to pedal uphill for hours on end, going nowhere, summer or winter, until the power comes back, this is the slavery of powering off of your bicycle, it works to provide some feeble current, but there are much better ways to spend your man hours and food calories. Notable exceptions are using a small wheel generator for bike lights or small battery charging like mobile phones as you travel, BTW you will need to add a rectifier and voltage regulator circuit since bike generators produce AC power, an inexpensive friction generator will wear on your tire, but hubs dynamos are expensive around $50 plus requiring a wheel rebuild. You could power an old belt drive Singer sewing machine, or flywheel for light machine shop tools, since these do not require such exertion, there are plans available for using a broken bicycle to put the pedal drive under your work table. If you want electrical power, then go with solar, wind, or a water wheel. Don’t be an energy slave. To move water make a water tower, cistern, or pond on a hilltop and pump using wind power, since it will be gravity fed you have available water in the storage and the pump will run every time there is wind refilling the storage. Other options are using a water wheel pump, or the very reliable inertial pump.
All the best to you and the family – David in Israel
Back Home magazine published an article on a bicycle powered water pump in their March/April 2009 issue (#99). The issue is available online for $3.75. – Matt