Mr Gandhi, 47, spent several hours at Sun Power and sought information on its advantages and disadvantages.
"The idea (behind visiting the center) was to really understand implications (of solar power) in India," senior Congress leader Sam Pitroda, who accompanied Mr Gandhi, said after his visit to Sun Power's research centre in the Silicon Valley.
SunPower Corporation is an American energy company that designs and manufactures crystalline silicon photovoltaic cells and solar panels.
He also visited the Tesla factory in Fremont in California on Tuesday.
Tesla is an American automaker, energy storage company, and solar panel manufacturer based in Palo Alto in California. The company specialises in electric cars, lithium-ion battery energy storage and solar panels.
After his visit, Mr Gandhi flew to Los Angeles. He is scheduled to interact with members of the think-tank community and local leaders there.