He was appointed by then Secretary of State Hillary Clinton in April 2010 as the first energy fellow of the Environment and Climate Partnership for the Americas (ECPA) initiative. He began service as the Science Envoy for U. S. Secretary of State John Kerry in 2016, but resigned over President Trump’s policies in August, 2017. He has served the State of California and US federal government in expert and advisory capacities, including time at the US Environmental Protection Agency, US Department of Energy, the Agency for International Development (USAID) and the Office of Science and Technology Policy.
Kammen helped found over 10 companies, including Enphase that went public in 2012, Renewable Funding (Renew Financial) a Property Assessed Clean Energy (PACE) implementing company that went public in 2014. Kammen played a central role in developing the successful bid for the $500 million energy biosciences institute funded by BP.
During 2010-2011 Kammen served as the World Bank Group’s first Chief Technical Specialist for Renewable Energy and Energy Efficiency. While there Kammen worked on the Kenya-Ethiopia “green corridor” transmission project, Morocco’s green transformation, the 10-year energy strategy for the World Bank, and on investing in household energy and gender equity. He was appointed to this newly-created position in October 2010, in which he provided strategic leadership on policy, technical, and operational fronts. Kammen’s work at the World Bank included funding electrified personal and municipal vehicles in China, and the $1.24 billion transmission project linking renewable energy assets in Kenya and Ethiopia.
He has authored or co-authored 12 books, written more than 300 peer-reviewed journal publications, and has testified more than 40 times to U.S. state and federal congressional briefings, and has provided various governments with more than 50 technical reports.