Bessie, it turns out, has more to contribute than just milk and the occasional moo.

In Rutland, cows are helping to produce enough electricity to power 300 homes.

The Jordan Dairy Farm now houses an anaerobic digester, which takes cow manure and food scraps, and cooks it to create methane gas, said Amy Zorich, spokeswomann for National Grid.

“Anaerobic digesters fundamentally improve the long term financial health and viability of family dairy operations,” said Mel Kurtz, president of quasar energy group, which built the digester. “For a multigenerational farming operation like Jordan Dairy, innovation and progressive thinking are the means by which they can position themselves for growth and prosperity in an ever changing world.”

The methane gas powers a generator, which sends energy back to National Grid. Each cow provides enough energy to power a Massachusetts home for more than a year.

“That is clean energy that is renewable and from a local source,” Zorich said.

National Grid and AGreen Energy, a consortium of five Massachusetts dairy farms, announced the development Thursday.