Electronics giant Apple has been granted permission to sell energy generated at its $850m (£645m) solar farm in California

Electronics giant Apple has been granted permission to sell energy generated at its $850m (£645m) solar farm in California. 

Last year, the tech firm acquired a 2,900-acre power facility in Monterey County, giving it 130 megawatts of solar energy capacity.

Now it has the go-ahead to sell that energy into wholesale markets.

Apple said renewable energy generated at the site could power 60,000 California homes.

One expert says power generated from solar farms is not consistent.

Dr Niall Mac Dowell, a lecturer in energy and environmental technology at Imperial College London, told the BBC that "just because Apple has invested in that capacity does not mean they'll get the same level of energy from it."

There is a big difference between installing solar panels and generating electricity from them, he said.

"Today, on a sunny August afternoon in the UK, we are getting about 0% energy from solar power."

He added: "It's awesome that Apple is investing in renewable power when it can, but that doesn't mean it's about to go off-grid."

'A positive step'

On Thursday, energy officials in Washington DC said Apple could sell its power at market-based rates. 

The Federal Energy Regulatory Commission also noted that Apple owns a similar 20-megawatt facility in Nevada, as well as a 50-megawatt facility in Arizona.

Last year, Apple said the Monterey County site could supply enough electricity to power all its stores, offices, headquarters and a data centre.

James Court, the head of policy at the Renewable Energy Association, described Apple's investment as "a hugely positive step".

He told the BBC: "A decent-sized gas power station can produce between 200 and 400 megawatts, so Apple's capacity is sizeable."

Apple's $850m investment in the Monterey County facility was announced last year as part of the corporation's bid to reduce its carbon footprint. 

Other major tech firms have investments in renewable energy. 

In June last year, Google purchased 236 megawatts of energy capacity from two wind farms in Sweden and Norway. 

Then in February, Microsoft announced it was experimenting with underwater data centres to reduce the energy consumed when cooling the facility. 

Mr Court expects energy self-sufficiency will become more commonplace across businesses in the future. 

"One of the growth areas in the UK is going to be companies self-supplying though solar power. I think we're seeing a rise of self-supplying already," he said.

The US owns 11% of the global solar power market, according to industry body SolarPower Europe. That's about three times as much as the UK's share (4%), and not too far off from the leading country China (19%).