Before Simmons joined the then President-elect's transition team to the DOE in January, he served multiple roles at the Institute for Energy Research (IER), most recently as Vice President for Policy. IER is a Koch-affiliated non-profit think tank that focuses on "energy analysis and free-market energy and environmental policy,” offering reports and analysis criticising plans to lower emissions and attacking renewable energy.
Simmons is also currently listed as a Policy Expert on the Heartland Institute's website.
Before joining IER, Simmons was Director of the Natural Resources Task Force at the American Legislative Exchange Council (ALEC), the Koch-tied organization designed to link state legislators with corporations and create templates for state legislation.
Simmons' old boss at IER, President Tom Pyle, served as the head of then President-elect Trump's energy transition team.