Google has said it will invest hundreds of millions of dollars in researching renewable energy technologies that will be cheaper than burning coal.

Google said the initiative, known as RE

Company co-founder Larry Page said at a press conference that Google plans to spend tens of millions of dollars on research and development and other related investments in renewable energy next year. Currently, coal supplies 40 percent of the world's electricity, according to Google.

"We have gained expertise in designing and building large-scale, energy-intensive facilities by building efficient datacentres," said Page in a statement. "We want to apply the same creativity and innovation to the challenge of generating renewable electricity at globally significant scale, and produce it cheaper than from coal."

Page said Google's 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," he said, adding that one gigawatt can power a city the size of San Francisco, which has a population of about 750,000.

Page said that if Google meets that goal and large-scale renewable deployments are cheaper than coal, then the world could meet a large part of its electricity needs from renewable energy sources and significantly reduce carbon emissions. "We expect this would be a good business for us as well," he said.

Google.org, Google's philanthropic arm, will invest in the RE

Google is now working with two California companies on renewable energy technologies: eSolar, which specialises in solar thermal power, and Makani Power, which is developing technologies to harness the wind for energy.

Google said its announcement is just the latest step in its commitment to a clean and green energy future.