• Jeff Ressler and Tom Hoff
    Jeff Ressler and Tom Hoff

    Tom Hoff, Founder and President, Research & Consulting

    Tom Hoff is the founder of Clean Power Research and President of its Research and Consulting Group. He is a pioneer in the science of valuing distributed solar generation and holds several patents in the area of PV fleet power estimation. Tom’s research is proving vital to utilities and ISOs, who are faced with the challenge of maintaining reliability while integrating ever-increasing levels of PV generation on the grid.

    Tom takes an analytical approach to problem solving and his mathematical models and methodologies are frequently integrated into the company’s commercial software products, making them readily accessible to the solar industry.

    Tom’s passion for innovation in the area of clean energy system analysis has made him a sought-after industry speaker and consultant for the PV industry, and he has published extensively for more than 25 years. His numerous research topics include: valuation of photovoltaics and distributed generation, risk management and renewables and, most recently, methods to characterize PV output variability. In performing his research, Tom has been known to test hypotheses using the PV and electrical systems in his own home.

    Tom began his career at Pacific Gas and Electric Company. He holds a Ph.D. in Engineering-Economic Systems from Stanford University’s School of Engineering.

    Jeff Ressler, President, Software Services

    As the President of the Software Services Group at Clean Power Research, Jeff is responsible for the business and technical aspects of the company’s software services, including PowerClerk®, PowerBill® and SolarAnywhere®. As a software industry veteran, he brings a wealth of experience in delivering highly available online solutions that customers value.

    Jeff’s interest in the clean technology industry is driven by the fast pace of technical innovation and the opportunities to help inform markets about the value of renewable energy technologies. Seeing the parallels with the early software and PC markets, Jeff is applying his insight and expertise to delivering software solutions that quickly and cost-effectively evaluate the financial impact of renewable energy technologies.

    Jeff’s career includes stints at both Oracle and Disney in addition to more than 10 years at Microsoft. During his tenure at Microsoft, Jeff served as Director of Product Management for Exchange Server and Lead Product Manager for SQL Server, among other roles. For more than two years, he was the speech manager for Bill Gates, who was Microsoft’s Chairman and Chief Software Architect at the time. Jeff holds a degree in Industrial Engineering from Stanford University.

  • Mark Liffmann, Vice President Sales, Marketing and Business Development

    Mark Liffmann brings more than 10 years experience helping renewable energy companies expand their businesses to the role of Vice President of Sales, Marketing and Business Development at Clean Power Research. Working in the renewable energy industry has allowed Mark to pursue his deep and enduring passion for both the environment and pioneering and developing new markets.

    Mark’s career includes co-founding one of the largest business units at SunPower where he led growth to over $500 million in annual revenue, and pioneered the successful expansion of the business unit to the European Union. While at SunPower, Mark also led the integration of the small commercial team after merging with PowerLight, and he helped form partnerships with numerous Fortune 500 companies. Previously at Solar Depot, Mark was responsible for doubling revenue and headcount in two years while serving as Vice President of Business Development and COO, and he established the groundwork for a successful sale of the business to Itochu.

    Mark’s experience also includes leading sales and business development efforts at EnerG2, a Seattle based energy materials startup, and serving at the law firm of Gunderson Dettmer, which specializes in financing emerging growth companies. Mark holds a B.S. in Physics and a B.A. in Public Policy from Stanford University, and a J.D. and an M.S. in Economics from Harvard University.

  • Ben Norris

    Ben Norris, Senior Consultant

    Ben Norris is a Senior Consultant at Clean Power Research in Napa, California. In managing the Consulting Group, Ben contributes his expertise in the areas of distributed generation and energy storage to performing technical analysis and development of new solar analysis tools. Subject areas include valuation of distributed PV, output variability and forecasting, energy storage technology, and incentive program design. Consulting Group clients include research organizations, financial institutions, utilities and manufacturers.

    As part of an experiment to develop and validate CPR’s PV fleet variability model, Ben developed and deployed a network of high-speed irradiance sensors. He also played a key role in developing a web-based toolset and methods for Value of Solar™ analysis in a project funded by NYSERDA and CPUC. His experience covers photovoltaics, solar thermal electric, flywheels, advanced batteries and fuel cells. He has developed methods for dynamically managing transmission line thermal ratings and for effectively using infrared imaging in Transmission and Distribution maintenance.

    After earning a degree in Mechanical Engineering from Stanford University in 1985, Ben worked as a research engineer at PG&E, later as an independent consultant. Ben served on the Board of Directors for the Electricity Storage Association for 8 years, and is a licensed Mechanical Engineer in the State of California.