The legendary energy executive, whose name symbolized big oil, died Wednesday at age 91. He founded the company that became Mesa Petroleum and later began a hedge fund focused on energy investments.

(Image credit: Larry W. Smith)

Prospects in the industry are dim, and even the billionaire investor, who made his fortune in oil, has turned to alternative energies. Still, the self-described "realist" says they aren't the answer.

(Image credit: Alex Wong)