How Now Cow Power?
Cows providing fuel for electricity
Chris Berdik Jan 9, 2018
IN A RURAL valley south of Deerfield, power lines strung on new poles run along a stretch of muddy gravel between the main road and the interior of Bar-Way Farm, where hundreds of cows provide electricity along with their milk.
Manure from the cows is pumped into a massive, red, airtight tank that acts like a giant stomach where microbes consume the waste and create biogas (mostly methane) to power a one-megawatt generator—a process called anaerobic digestion. There aren’t enough cows here, or at any Massachusetts dairy, to power a system this size with manure alone, so it’s supercharged with a slurry of food waste delivered by tanker trucks a few times every day.
When the state banned commercial food waste from landfills in October 2014, anaerobic digestion advocates predicted a win, win, win—a much-needed destination for food waste, an economic lifeline to endangered dairy farms, and a new source of clean energy. But only two new digesters have started up on farms since then. (Two were in place before the organics ban and three non-farm digesters have started taking food waste since 2014.)