The US Department of Energy (DOE) has provided a boost to the US solar industry with offers of loan guarantees for two major solar power projects in the state of California.

The DOE said in April that it had offered conditional commitments for a $1.187 billion loan guarantee to support SunPower Corporation’s California Valley Solar Ranch project, and for a $2.1 billion loan guarantee for Units 1 and 2 of the Blythe solar power project, which is being developed by Solar Trust of America.

The loan guarantee offers mark a critical financial milestone in the realisation of the two projects and will also help to drive forward the development of large-scale renewable energy projects in the US.

Blythe Units 1 and 2 will add a combined 484 MW of concentrating solar power (CSP) to the Californian grid, while the California Valley Ranch project will add 250 MW of photovoltaic (PV) generating capacity.

“The efficiencies created by the California Valley Solar Ranch project will help lower the cost of solar power and encourage more utility-scale solar deployment,” said US Energy Secretary Steven Chu. “Loan guarantees play an important role in facilitating the development and deployment of innovative technologies at massive scope and scale.”

Units 1 and 2 of the Blythe project represent the first phase of a larger project that, when completed, will generate 1000 MW of solar power using parabolic trough technology. The array will include an air-cooled condenser unit, which will decrease water use by nearly 90 per cent compared with a water-cooled CSP facility.

The California Valley Solar Ranch will be the largest utility-scale PV project in the US to utilise tracking technology combined with an innovative monitoring system that will improve annual output by approximately 25 per cent compared with traditional fixed PV installations. Pacific Gas and Electric Company, the largest utility in California, will purchase all the plant’s output.