This just in: My August electric bill. August was the first full month (Billing cycle month, that is) in which my solar hot water heater has been fully functional. Compared to August 2006, my consumption of electricity has gone from 27 kWh/day, to 15 kWh/day. At $.16 per kWh, that's $2.43 per day, as opposed to $4.42 per day. Realized savings for the first month: $61.69 Final cost of system: $3600 - 30%(Federal tax credit)= $2520 At this rate, payback will occur in 3 years, 5 months. But of course, this will not be the case since there will be less sun in the coming months. It is my conjecture however, that even more will be saved during the temperate months since during the summer we tend to use the least amount of hot water. A lot of electric use was for the whole-house fan and the dehumidifiers (and refrigerator). I'm gonna go burn some tires in celebration!