Californian solar thermal start up BrightSource Energy yesterday announced it has secured $115m in funding from a group of blue chip investors, including Google, BP Alternative Energy and StatoilHydro Venture.

The investors joined asset management firm Black River, as well as original backers VantagePoint Venture Partners, Morgan Stanley, DBL Investors, Draper Fisher Jurvetson, and Chevron Technology Ventures in the round which takes the total raised to date by the company to over $160m.

John Woolard, chief executive of BrightSource, said that the blue chip nature of the investors underlined the "confidence that major strategic players have in our ability to reliably generate clean, cost-effective, utility-scale solar power".

The company said it would use the funding to accelerate its plans to deliver utility scale solar farms based on its solar thermal technology, which uses thousands of small mirrors called heliostats to concentrate the suns energy on a central tower. The heat is then used to create steam, which drives a turbine.

BrightSource, which earlier this year entered into a series of power purchase agreements with US energy giant PG&E to deliver up to 900MW of electricity, claims that each of its solar towers can generate up to 20MW of power with a farm facility featuring five solar fields capable of delivering 100MW of clean energy.

BrightSource founder and chairman Arnold Goldman said that the approach was more energy efficient and cost effective than traditional solar thermal technologies such as parabolic troughs which are typically expensive to manufacture.