For those interested, I have just received my third electricity bill after the installation of my solar hot water heater. Currently, I have realized at total of $158 "saved." Putting that against ~$3500 of total cost, then somewhere between $1200 and $2000 federal tax credit , and the diddly-squat credit from Northeast Utilities, I am on target for a 4-year payback. Caveat: I did the labor myself, which included 150 soldered joints, 20 threaded joints and 10 compression unions. I have to find out how much I can claim for the labor as a tax credit. A friend says I should claim $50 an hour at least. Anyone know any thing about writing off you own home labor?