Manure Manager

Features Anaerobic Digestion Applications Business/Policy Dairy Energy United States
Investment in California dairy digesters pays off

March 11, 2016  by Manure Manager

A new study shows dairy digesters - such as the Pixley digester - are among the most cost efficient investments California can make to reduce greenhouse gas emissions and achieve climate change prevention goals. Photo by Ryan Krauter/4Creeks Creative


Dairy methane digesters are among the most cost-effective investments the state can make to reduce greenhouse gas emissions and help achieve California’s climate change prevention goals, according to a new study by Ramboll Environ.

The study examines how cap-and-trade auction proceeds are being invested by the California Air Resources Board.

“Dairy anaerobic digesters are a proven and highly effective method of reducing greenhouse gases, particularly methane, from agriculture,” said Dawn Chianese, the study’s primary author. “As such, dairy digesters are a smart investment of auction proceeds, particularly in light of their ability to substantially reduce short-lived climate pollutants and their potential to provide significant criteria pollutant reductions and benefits to disadvantaged communities.”

According to the study, projects currently funded by the state provide a return on investment ranging from as low as $2 to as much as $1,250 per metric ton of carbon dioxide equivalents reduced. Dairy digesters represent one of the most cost effective investments of state funds with a rate-of-return of just $7 per ton of reduction. Equally important, because dairy digesters destroy methane, the value to the state’s efforts to address climate change is much greater because climate-forcing emissions reductions can be realized sooner. When these short-term investments are factored in, the cost per ton of reduction is closer to $2.

“Dairy digesters provide great bang-for-the-buck when compared to other investments,” said Michael Boccadoro, executive director of Dairy Cares. “California and Governor Brown need to make a five-year commitment of at least $100 million per year to help the state address dairy methane emissions and make major progress toward the state’s ambitious climate protection efforts.”

Speaking at the United Nations Climate Summit in Paris in December, Governor Brown said tackling short-lived climate pollutants (SLCPs) “is probably the most immediate challenge, and the most important thing to do leaving this conference.” The report can be read by visiting





Stories continue below