Using solar panels to save on electric bills is becoming increasingly common around the District, but solar thermal is a little harder to find. Solar thermal panels use heat from the sun to warm a home or run a water heater.
There are also systems that use special windows to absorb heat. They're a little harder to find in D.C. in part because there haven't been local subsidies for them, until now.
The District is now offering to pay for 20 percent of up to $5,000 of an installation. On top of that, there's a federal tax credit that will pay for a third of the cost. When all is said and done, contractors estimate the total cost for a system would be around $4,000. After that, heating the home would be free.