When it comes to the greenhouse gases causing climate change, methane is mighty. Methane gas is more than 20 times better at trapping heat in the atmosphere than carbon dioxide.
One of the chief contributors of methane gas to the atmosphere: cow manure.
Some Northwest Natural customers (roughly 11,000 of 600,000) are paying to reduce methane emissions from dairy farms by turning cow poop into electricity. By tacking on an extra $6 a month to their gas bill to help pay for a methane digester, they can offset the carbon emissions from their gas use.
The carbon offset arrangement – orchestrated by The Climate Trust – has turned out to be a pretty good deal for dairy farmer Buzz Gibson. He’s hosting a new digester project at Lochmead Dairy in Lane County. He used to funnel manure into a lagoon on the farm, where methane would bubble up out of the water while the solids settled to the bottom. Later, the solids were used as fertilizer.
The anaerobic digester changes the operation considerably. It contains the manure in three silo-like units and keeps it warm while trapping the methane gas produced as microbes digest the poop. The gas is burned in an engine that converts it into electricity.
The process can take around 150 pounds of poop each of Gibson’s cows produces per day and turn it into enough electricity to power 300 local households a year. There are carbon dioxide emissions from burning the gas, but they’re not methane emissions. So, there is a net greenhouse gas benefit when all is said and done.
In Germany, 40 percent of the dairies utilize methane digesters. In the U.S.? 2 percent. So far…