Officials from Massachusetts and the Commonwealth's biggest electric utility ceremoniously activated three solar power plants that will generate enough to power as many as 470 homes, according to published reports.

Plants in Revere, Everett and Haverhill cost slightly more than $15 million, the Associated Press reports. The plants derive from the Green Communities Act, according to the Boston Globe, which Governor Deval Patrick kicked off in 2009. National Grid is partnering with Massachusetts to encourage renewable energy.

"We are proud to help the Commonwealth advance its green energy and green economy goals," according to a statement from Edward White, vice president of energy products at National Grid.

The three solar plants generate enough clean energy to displace emissions created by more than 1,100 passenger cars, according to National Grid.

National Grid won approval to build five plants. The three join a $6.5 million solar plant in Whitinsville, which began operation in May and generates enough electricity to sustain almost 200 homes. The fifth plant, in Dorchester, is slated to begin operation early in the summer of 2011.

All five plants will generate a total of 3.4 megawatts of energy.