Karen and Brian Czarnowski had long kicked around the idea of putting solar panels on the roof of their Galesville home.

As former live-aboards on a sailboat, they're keenly aware of how they use resources such as power and water. Add to that concerns about climate change and pollution, and they're the perfect candidates for solar power.

But the staggering cost kept them from following through.

"At that point, the government incentives were pretty poor," Mr. Czarnowski said.

But once the state made its incentives much more generous this year - up to $10,000 per home - the Czarnowskis, and dozens more Maryland...