Doug and Tom Block of Illinois have installed a methane digester on their family dairy farm. The digester breaks down waste from more than 800 cows and captures methane that is then used to fuel electrical generators, providing a third of the farm's electricity, the Chicago Tribune reported Thursday.

Methane is a greenhouse gas 23 times more potent than carbon dioxide, the newspaper said. The U.S. Environmental Protection Agency estimates that livestock account for more than a quarter of the nation's methane emissions.

The Blocks not only keep methane out of the air and save money on electricity, they also make money by selling carbon credits through the Chicago Climate Exchange to companies that fail to meet their pledges to reduce emissions. The farmers recently received $24,000 from the arrangement, the newspaper said.