But the power didn't all come from Massachusetts. In fact, the percentage of clean electricity imported from outside the state increased from about a quarter of the total in 2006 to about a third in 2007. The bulk of the imported power came from New York state landfill methane plants and wind farms, and from Canadian wind farms. More than two-thirds of the increase in imported power came from Canada.

Solar power represented only about one percent of Massachusetts' renewable electricity in 2007. Nearly half of the power, 49 percent, came from biomass. Another 30 percent came from landfill gas, and 19 percent from wind. The remaining two percent came from Anaerobic Digestion.

The report cites off-shore wind farm's potential as a major source of clean, home-grown electricity in the future.