BlueWave Capital, an energy company with roots in Boston, is teaming up with a Utah-based company Vivint Solar, to better sell Massachusetts customers on the power of the sun. Both companies are gearing up to offer community solar to areas in Massachusetts. Rather than install panels on the roofs of individual houses, community solar projects place panels on open project sites in a particular city or town. Subscribers can buy into the project and tap into the power generated for their homes. BlueWave has a total of 14 projects underway in four towns in the state, and the new partnership will sell memberships in two of those towns, Fairhaven and Oxford, at the outset.