About

We develop, build, operate, & improve biogas projects all across the United States.

Our Journey

After finishing up a career in the US Air Force in 2007, Daryl Maas came back to his hometown in northwest Washington. Working with childhood friends and family relations, he built the nation’s first successful dairy digester business model by operating manure digesters as a tenant on family dairy farms.

In 2010, Daryl moved with his wife and two (now three) kids to Redding, California. He founded Maas Energy Works (MEW) to explore the growth opportunities in the California renewable energy market. After connecting with Leo and Peter Van Warmerdam, MEW completed its first California dairy digester on their dairy in May of 2013. The site is still going strong 11 years later.

MEW has since developed 70+ new or upgraded dairy digester facilities across eleven states, making MEW the most experienced dairy digester developer in the United States. We are proud to say that every digester we’ve developed is still in operation today. As a digester developer, MEW meets the dairy farmer and builds a business model that works for both parties.

Our Leadership Team

Daryl Maas

Chief Executive Officer

Starting as a one-man consultant and building a 180+ employee developer-owner-operator powerhouse, Daryl Maas possesses as much direct experience as anyone in the US biogas industry. Over a biogas career spanning 18 years, he has overseen the development of 70+ successful digester projects. Daryl’s work includes the largest dairy digester cluster in the world, the first dairy biogas pipeline injection facility in California, the first CalRecycle-licensed food waste co-digestion facility, and numerous successful restarts of previously abandoned third-party digesters.

Known for his community involvement and active lifestyle, Daryl loves spending time with his wife and kids, playing pickleball, coaching sports, and traveling – recently exploring his Dutch heritage. A history buff and natural teacher, he’s always eager to share his knowledge.

Mike Gross

Chief Operating Officer

Michael Gross is an energetic and human-heart leader - who helps steer the direction of Maas Energy Works. Originally from Munich, Germany, he holds a German and French engineering degree and has worked across industries like automotive and microelectronics, managing businesses around the world. His sense of adventure led him to move his family to Redding for ministry school, seeking a deeper purpose. When he’s not solving complex problems, he’s having fun mountain biking, snowboarding, or tinkering in his workshop.

Geo Osorio

Chief Personnel Officer

Geovany Osorio is the Chief of Personnel at Maas Energy Works, where he leads the Department of Culture and Talent. Originally from Ecuador, "Geo" holds a Master’s in Business Administration and brings years of leadership experience, including his time as General Manager of a manufacturing plant and previously directed the Maas Motor Works branch of MEW. Outside of work, Geo enjoys life with his wife and four kids, weekend trips, and returning to Ecuador for missions. He’s a competitive pickleball player, avid mountain biker, and a big fan of chocolate and quality time with friends and family.

Christianna Maas

Vice President

Christianna Maas has been the heart of Maas Energy Works’ growth, blending strategic vision with a deep commitment to workplace culture. She was the catalyst behind our uniquely and aptly named “Department of Culture and Talent” (DCT) and has championed employee well-being through counseling and coaching programs.
Christianna ensures people are purpose-full and peace-filled, coining our hiring motto, “good jobs for good people,” to shape an environment where individuals thrive both personally and professionally. A behind-the-scenes force, she brings thoughtfulness and intention to every decision, creating a connected and flourishing team. Her leadership, rooted in faith and care, continues to fuel the company’s success and foster wholeness in those around her.

Stephen Hatley

Chief Financial Officer

Stephen Hatley is the CFO and partner of Maas Energy Works, joining the company at its inception in 2010. He has played a crucial role in driving the company's growth, securing over $600 million in financing through grants, private capital, bank loans, and government-guaranteed loans. Outside of his professional accomplishments, Stephen is an avid cyclist, enjoys traveling, and participates in racket sports. He is also passionate about emotional health and supporting human rights initiatives throughout the world.

Chief Acounting Officer

Ricky Timms

Ricky Timms is the Chief Accounting Officer at Maas Energy Works. After high school, Ricky moved to the U.S. with his family and kicked off his career in public accounting, specializing in tax compliance and consulting for Private Equity Funds. A CPA by trade, he keeps the team on track with our numbers, while bringing his South African energy and a sense of camaraderie to the MEW culture. In his personal time, Ricky loves spending time with his wife and kids, and staying active through CrossFit, soccer, and tennis.