Google believes the technologies need to go to the next level

The Californian firm wants to make green energy sources of electricity cheaper than that produced from coal.

Its new initiative will focus in the first instance on solar thermal power, wind power and enhanced geothermal systems.

The support, to be channelled through philanthropic arm Google.org, will go to firms, R&D labs and universities.

Google also plans to do research itself, and will be hiring its own engineers and energy experts. It says renewables have to be taken to the next level if fossil fuel burning's impact on the climate is to be tackled effectively.

Need for speed

"With talented technologists, great partners and significant investments, we hope to rapidly push forward," said Larry Page, Google co-founder.

"Our goal is to produce one gigawatt of renewable energy capacity that is cheaper than coal. We are optimistic this can be done in years, not decades."

One gigawatt can power a city the size of San Francisco, one of California's biggest cities.

Google is already backing fuel-efficient cars. Google.org is giving out grants to help commercialise plug-in hybrids and fully electric vehicles.

The company itself has a 1.6-megawatt solar panel system installed at its headquarters in Mountain View, California.

Google said it expected to focus its early efforts on solar thermal technology, and would be spending "tens of millions" of dollars in 2008 on the initiative. In the future, however, this support should grow considerably.

Positive feedback

The firm has already begun working with what it regards as promising approaches in the state of California itself.

These include Makani Power Inc, which is developing ways to generate electricity by harnessing high-altitude winds.

Google thinks it has to get renewables producing electricity for a price of 1-3 cents per kilowatt-hour.

"Solar is currently substantially more expensive than coal, depending on the type that you have; but we see a lot of evidence from all the people working hard on this that the costs can come down quite a bit," said Larry Page.

"It's an ambitious goal to get it cheaper than coal but it seems obtainable; and certainly if we can, it will have a huge impact."