Using a 50% discharge rate, I can go two to three days without having to fire up the genset, and usually get a 100% charge within 3 to 5 hours using less than 2 1/2 gallons of biodiesel. The complete cost of building the biopowered genset was under $250.00 including the 100 amp alternator. Of course, this does not include the battery bank, Incharge regulator, Inverter, ect... I used a rather large diesel engine because it was available to me at an affordable price, but any diesel engine which produces 10 HP can be used. Biodiesel can be produced for around $.60 per gallon after the initial purchase of material. It still amazes me that my homemade genset and biodiesel produce enough power for me to run several rooms of my house and this computer.
Home Brew Biodiesel Genset hehehe
I was playing with the idea of attaching various devices to a single axle. Like spinning a washing machine while the generator runs but use it the other way around, fill the battery when washing. Heat can also be drawn from the motor, then can already power the washer with the scraps. After the water has drawn some heat from combustion a hydrosonic pump can make the water hot. Then store the hot water for baths, showers, cleaning and heating. I try make it all into one device with as few transmissions as possible. Add a solar boiler, solar panels and some wind mills. Use everything :-)