Critics of the contract between National Grid and Cape Wind frequently blast it as a no-bid deal. In fact, National Grid did consider alternative ways to meet its state-mandated requirement to derive more of its power from renewable sources. But it chose Cape Wind over competing smaller projects, including land-based wind, solar, and biomass.

The Legislature has mandated greater use of renewables both to reduce the Commonwealth’s carbon footprint and to give a boost to state and regional clean-energy companies. Last week’s announcement that a wind-turbine blade maker will open a plant in Fall River illustrates the potential. With energy policy in the country as a whole paralyzed by congressional stalemate, Massachusetts at least has a chance to make itself a leader in clean-energy industries. That includes high-tech batteries, hydrogen fuel cells, cellulosic ethanol, and — since the Northeast is the Saudi Arabia of wind — wind energy.

Calculating that dividend from the National Grid/Cape Wind deal might not be within the purview of the DPU, but it is a major reason why the project continues to deserve the Commonwealth’s support.