Professor Huemmler was with Exelon and its predecessor, PECO Energy, for 20 years. He started his career at PECO as an energy conservation analyst and finished at Exelon's Power Team as a senior power transactor buying and selling electricity in wholesale power markets. He was a member of the New England Power Pool's Transmission Operations Committee and participated in the rulemaking process which created a market-based power pool. Prior to joining PECO Energy, Andy worked in the City of Philadelphia's Energy Office in the Green administration. He authored an Energy Emergency Operations Plan for the City of Philadelphia and implemented the City's first neighborhood-based energy education program. Early in his career, Andy also worked for a small hydropower developer and the Philadelphia Water Department.

Andy has a Bachelor of Applied Science degree from the Towne School of Engineering at Penn, a Masters Degree in City Planning from Penn, and a Ph.D. in Social Systems Sciences from the Wharton School at the University of Pennsylvania. His doctoral research focused on "Facilitating Conditions for the Adoption of New Regulatory Technologies in the Electric Utility Industry."