The move will cost about $125,000 more per year on top of the agency´s annual electricity bill, which averages $1.2 million, the DEP said.

But the decision also will reduce carbon dioxide emissions by 3,716 tons per year, the agency said. That is the equivalent of taking 730 cars off the road, or using 7,839 fewer barrels of oil.

"Connecticut has adopted an aggressive Climate Change Action Plan, and we are a leader in addressing clean air and climate change issues," Gov. M. Jodi Rell said. "As part of these efforts, we have a goal of purchasing 20 percent of the state´s energy from clean sources by 2010. Today´s announcement at DEP is a very positive first step toward achieving that goal."