About Sage

In 2005, David Williard founded Sustainergy Systems in rural Marin county to help local ranches and businesses reduce energy costs and make the switch to renewables. In 2009, David was joined by his brother, Tom Williard, a software engineer and local school board member, and Brent Johnson, a civil engineer with a background in water and environmental engineering, to form Sage Renewable Energy Consulting.

By 2014, Sage had established itself as a leading project management and energy consulting firm for California businesses, public agencies and school districts. Our team has evaluated and managed more than 300 MW of renewable energy, including the largest contracted commitment to solar by a public school district in North America—Kern High School District’s 27-site solar project. Other professional services firms—financial advisors, architects, construction managers, and legal teams—also turn to Sage for auditing and due diligence of energy projects. 

Our projects have saved hundreds of millions in energy costs for our clients, providing enduring benefits for the environment, resources, and fiscal health of their communities. We've helped more than 100 public and private organizations become leaders in the transition to renewable energy. 

Brent Johnson, Tom Williard and David Williard at the construction of a wind turbine at McEvoy Ranch in 2009.

Brent Johnson, Tom Williard and David Williard at the construction of a wind turbine at McEvoy Ranch in 2009.

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Tom Williard

  • 15 Years Experience, Renewable Energy
  • 20 Years Electronics, Software & Hardware Engineering

Tom has more than 15 years of experience as a professional energy
consultant, with a focus on the development of technical and financial models that are now widely used to assess renewable energy systems and to predict potential energy generation and financial performance, serving as CEO since Sage’s inception. In 2013, Tom cofounded SolEd Benefit Corporation and wrote the project financial models used to structure PPA and lease financings that reduced the cost of renewable energy projects for public schools. In 2005, he cofounded Solmetric, a company that developed the SunEye, a high precision instrument now widely used in the solar industry to measure shade characteristics. In 2001 he cofounded System Design, a renewable energy system design and due diligence company.

Prior to 2001, Tom worked in electronics engineering in senior hardware and software engineering positions and in engineering management. Tom served for seven years as an elected public school trustee in Marin County. As a Sage Principal, he provides financial, policy, and technical oversight for all company projects, and provides expert testimony for clients and industry groups.




Brent Johnson, P.E., LEED AP

  • 15 Years Experience Civil-Environmental Engineer
  • 9 Years Renewable Energy Sector

During his time at Sage, Brent has developed custom financial and energy modeling tools and managed all aspects of renewable generation projects including feasibility studies, system design, project bids and construction, commissioning, and environmental credits management. Brent has worked on over 100MW of renewable projects encompassing technologies such as solar PV, storage, solar thermal, wind, and hydropower. His previous experience in the US and overseas has included design of large municipal facilities, construction management, operational support, and CEQA permitting. He has overseen all aspects of project development from concept to commissioned facilities, including serving as a construction manager on a complex, $170M multi-year linear project. Brent holds an M.S. in Civil-Environmental Engineering from UC Berkeley and currently serves as a director for his local water and fire district.




David Williard, LEED AP

  • 22 Years Experience, Environmental Project Planning and Energy Consulting
  • 14 Years Renewable Energy Project Planning, System Feasibility & Construction Oversight

David is a founder and Principal at Sage Renewables. He has over 22 years of experience working as a professional environmental consultant, with a focus on energy efficiency and renewable energy generation for the past fourteen years. David has managed all aspects of renewable energy projects, from planning and feasibility through implementation and operations for over 70 public and private clients. He has helped develop over 130 MW of renewable energy projects, including managing the largest solar PV project implemented by a school district in North America, at 27 sites in Kern County, CA.

Prior to starting Sage, he founded Sustainergy Systems Consulting and Design, and was owner and Principal from 2005 to 2009. At Sustainergy, he and his brother, Tom, provided “cradle to cradle” energy consulting services to private companies and government agencies. David was a contributing author of the ICLEE Sonoma County Greenhouse Gas Emissions Inventory, in 2004, and produced the Climate Action Plans for all nine cities in the County in 2005-2006. His prior experience included work as a wilderness skills and environmental education instructor, and a wetland and biological field technician for the National Park Service. David has also taught courses on the fundamentals of renewable energy generation and system design at Sonoma State University and the Solar Living Institute.


Our Team