It started off as a small brainstorming idea on how to deal with a power outage and keep my fish alive. Alternative power is incredibly fascinating. Expensive, but fascinating. The thing I've quickly realized is your dollar per watt goes down as you go up in wattage. Better to buy in bulk I guess. To keep the fish alive, I need a continuous 31.5 watts of 120 VAC. That wouldn't be too difficult with a solar cell and a couple deep cycle batteries. Only thing is a 40-50 watt solar cell is over $300 easily So then I started thinking, how long would it take for alternative energy to pay off? Say I set up my aquariums to run only on solar power. My guestimate of my current electric utility is about 7 cents per kilowatt-hour. My aquariums only cost 77 cents a year in electricity. But that's just running the filters. Counting the lights, and heaters, it's only $11.70 a year. I pay more for the water doing water changes than I do electricity! It would be easier and cheaper to get a gas generator and be able to produce kilowatts of energy. Convert the gas generator to natural gas or propane, and never worry about gas going bad.