In the mid-1990s, a few energy activists in Massachusetts had a vision: What if citizens had choice about the energy they consumed? Instead of being force-fed electricity sources selected by a utility company, what if cities, towns, and groups of individuals could purchase power that was cleaner and cheaper? The small group of activists — including a journalist, the head of a small nonprofit, a local county official, and a legislative aide — drafted model legislation along these lines that reached the state Senate in 1995. The measure stalled out….