Green and gooey fuel attracts Bill Gates' backing

Microsoft founder turned billionaire philanthropist, Bill Gates, has turned his arm to cleantech investment this week, contributing to a $100m investment in third generation biofuel developer Sapphire Energy.

The US-based company said it now hopes to bring its "green crude" to market in the next three to five years.

"With this investment, Sapphire has the resources to make partnering decisions independent of the need for financing, and the ability to build our first commercial facility with internal funding," said Sapphire chief executive Jason Pyle.

The company has built a system that uses algae, sunlight, CO2 and non-potable water to produce what it calls "renewable gasoline".

Biolfuels made from algae have secured significant support from investors and environmentalists because unlike controversial first generation biofuels, they do not need arable land to be produced.

Sapphire said its end product is similar to light sweet crude and can be refined into chemically identical fuel products, such as gasoline, jet fuel and diesel products, that are entirely compatible with the current energy infrastructure.

Other investors include ARCH Venture Partners, Wellcome Trust, Venrock and Cascade Investment.