ABC News:

A new concept in renewable energy is catching fire across the country, allowing customers who might find solar panels too expensive or impractical to buy green energy anyway.
 
 Community solar gardens first took off in Colorado a few years ago, and the model — also known as community or shared solar — has spread to Minnesota, California, Massachusetts and several other states. Capacity is expected to grow sharply this year, and interest is up among both residential customers who just like the idea and large companies that want to cut their carbon footprints.
 
 The gardens feed electricity to the local power grid. Customers subscribe to that power and get credit on their utility bills, with contracts that typically lock in for 25 years and shelter against rate increases. Some developers say customer bills will drop below regular retail rates within a few years; others say the savings begin immediately.