Maine identifies as a clean energy state. Roughly 60 percent of the energy produced here comes from renewables: About half from hydro, half from wood-fired power plants and 10 percent from land-based wind. But the hydro and biomass plants are aging. Ambitions for offshore wind have largely stalled and natural gas has become the region’s dominate fuel source for electric generation. Against this backdrop, can Maine businesses fashion an energy future based on renewables and efficiency, and what are the political and economic obstacles?