A dotcom entrepreneur, who had a tryst with the solar energy at the age of 15, is back in news for his solar power projects including one in solar thermal power at the age of 49.

It was in 1973 when Bill Gross figured out how to build parabolic concentrators and Stirling engines to capture the sun's energy. After 35 years, Gross is once again being acknowledged for his solar power projects supported by his company Idealab.

Gross' passion for alternative energy got re-kindled in the wake of Internet boom melting down and the California energy crisis of 2000.

Commenting on solar technology, he reportedly said, "I thought, I could pick up where we left off."

Gross' Idealab, which provides a broad range of operational support to companies, has founded ventures such as eSolar, Inc. and Energy Innovations among the others.

eSolar designs and develops utility-scale CSP projects starting at 33MW. Recently, the company had signed a 20-year contract to supply utility Southern California Edison with 245 megawatts of green electricity.

Bandel Carano, a managing partner with Oak who also sits on eSolar's board, called Gross' solar thermal technology a breakthrough equivalent to the advantages of PC computing over mainframes, according to Reuters.

Currently, he is also the founder and CEO of Energy Innovations, a firm, which manufactures commercial solar products that maximise usable energy from the sun.

As highlighted by Reuters, half of Idealab's 16 companies are focused on energy, and it has learned to be more disciplined than in the late 1990s. "We used to have 40 ideas a year and do one company a month," he said. "Now, we have 40 ideas a year and we're doing one company a year."