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Dairy Farm Sunset


Manure is a resource. For years, dairy farmers have been collecting cow manure, storing it, and using it as a renewable fertilizer. A manure digester unlocks even more value by extracting energy from manure. A digester is a tank or pond that contains manure, but captures the methane gas emissions that would otherwise escape into the atmosphere. Naturally-occurring bacteria in the manure break down the organic matter and create biogas. The biogas primarily consists of methane, an energy-rich fuel. The biogas fuels electrical generators that supply power to the grid, or supply onsite needs.


In partnership with dairy farmers or other commercial facilities, Maas Energy Works specializes in developing, owning, and operating these anaerobic manure digesters. Daryl Maas, president of Maas Energy Works, has learned about digesters not by selling them to others, but by building, owning, and operating them himself. Maas got started in cow power in Washington State with his brother. In 2010, Maas continued to expand by bringing Maas Energy Works to California in order to explore the large renewable sector growth there. Today the company develops, builds, operates, and improves biogas projects all across the United States.

Methane Digester

I’m passionate about taking waste and making it into something useful. It’s just such a great picture of what humans are called to do. - Daryl Maas

After hundreds of thousands of operating hours in three states and processing the manure on nearly 20 farms, we know how to build and run these projects. Our projects are cost-effective and efficient, reliable in real-world field settings. 

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