S. David Freeman, green-energy champion who advised presidents, dies at 94

S. David Freeman, an engineer, lawyer and Stetson-sporting “green cowboy” who championed renewable energy, advised three presidents and led some of the nation’s largest public utilities, died May 12 at a hospital in Reston, Va. He was 94.

The cause was a heart attack, said his son Stan Freeman.

Mr. Freeman was an outspoken Tennessee native known for his cream-colored cowboy hat and singular obsession with energy conservation. Working in the 1970s as a White House adviser and Ford Foundation researcher, he emerged as “an energy prophet,” as the New York Times once put it, by arguing that utilities should focus on energy efficiency more than energy production — a minority view that gained growing acceptance over the next two decades.