Solar Hot Water First. Then Photovoltaics. : TreeHugger

Solar Hot Water First. Then Photovoltaics. : TreeHugger

The solar power subsidy is an equal opportunity employer; according to Brian's post, "any solar system you purchase this year is 30% percent off, thanks to the government (or at least, you'll get a tax rebate for that much). Solar powered water heaters are eligible for 30% off, too."

But what do you get for those dollars?

The evacuated tube solar hot water heaters like the one shown in the top picture are getting really cheap now that the Chinese manufacturers are cranking them out- the salesman told me that he could put one on my house for $ 3,000 and that it could serve a family of four.

That would replace a conventional electric hot water heater that uses roughly 15kWh of energy per day. A natural gas heater probably uses pretty much the same, albeit cheaper, energy. But essentially, putting that solar heater on the roof offsets 15kWh worth of energy per day from other sources.