Tech giant Apple has permission to sell electricity.

Energy generated at Apple’s US$850 million solar farm in California can now be traded on wholesale markets.

The 2,900-acre facility in Monterey County has about 130 megawatts of solar energy capacity, enough to power tens of thousands of homes.

Government energy officials say Apple can sell its power at market-based rates.

It is not the iPhone manufacturer’s first step into the electricity game, with Federal Energy Regulatory Commission approval already being secured for a 20-megawatt facility in Nevada and a 50-megawatt facility in Arizona.

In fact, it is far from the only major tech firm to have investments in renewable energy.

Google owns 236 megawatts of energy capacity from wind farms in Sweden and Norway, while Microsoft is experimenting with underwater data centres to reduce energy-use through natural cooling.

The US runs about 11 per cent of the global solar power market, considerably more than the UK's share (4 per cent), but a way off from China’s 19 per cent.