Mac began his career in environmental law. He has worked for a U.S. Representative, two U.S. Senators, and two federal judges. Mac has also worked in the U.S. Department of Energy Office of General Counsel, the U.S. Department of Justice
Environment and Natural Resources Division, and the U.S. Environmental Protection Agency Office of Enforcement and Compliance Assurance.
Green hydrogen—hydrogen produced from water electrolysis using renewable or low-carbon electricity—has received the lion’s share of attention. But little attention has been paid to biohydrogen (Bio-H2)—a type of hydrogen produced from waste biomass.