John W. “Bill” Yerkes, a Stanford-trained engineer who for decades championed the cause of solar cells for commercial use and was known as the “father of the solar industry,” has died in Santa Barbara. He was 79.

After working on solar arrays in space for Boeing, he left to join Spectrolab, which in the late 1960s produced solar arrays for the Apollo 11 mission to the moon.

He founded Solar Technology International in Chatsworth and after its sale to ARCO, moved the company to Camarillo, where it still operates as the California base for German manufacturer SolarWorld AG.

SolarWorld said it mourned Yerkes’ death, citing his vast influence on the industry. “Many of todays solar-industry veterans got their start under the influence of the leadership, processes and products that Yerkes brought to the industry,” the company said in a statement.

Yerkes left ARCO in 1985 to found a new, thin-film solar startup and in 2005 was a co-founder of Solaicx, which grows low-cost silicon crystals for solar cells.

“Yerkes is the father of the modern solar industry,” Raju Yenamandra, SolarWorld’s vice president for business development, said in the company’s statement. Yenamandra worked with Yerkes in Camarillo in the 1980s but remained with Arco.

SolarWorld’s Camarillo operation has been hard hit by competition from lower-cost Chinese-made solar panels. The plant, which bills itself as the longest continuously operating U.S. panel maker, was forced to cease operations in 2011. A small research, development and sales effort remains operational, but more cutbacks are planned through June.