Google's core business is Internet search but that isn't keeping the company from exploring some other very different areas.

On Tuesday, Google announced an ambitious plan to develop electricity from renewable energy sources that will be cheaper than electricity produced from coal. The newly created initiative, known as RE < C, will focus initially on advanced solar thermal power, wind power technologies, enhanced geothermal systems and what Google referred to as "other potential breakthrough technologies."

As part of its capital planning process, Google said it anticipates investing hundreds of millions of dollars in breakthrough renewable energy projects which generate positive returns. Near term, Google said it plans to spend tens of millions of dollars next year on research and development and related investments in renewable energy.

"We have gained expertise in designing and building large-scale, energy-intensive facilities by building efficient data centers," said Larry Page, Google's co-founder and president of products, 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."

While there was no timetable released on when the first fruits of Google's renewable energy efforts might see the light of day, it has at least one specific target. "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," said Page. (One gigawatt can power a city the size of San Francisco.)

Page said there are several promising "green" technologies that will benefit from further investment and research into making them more cost competitive. Solar thermal technology was one example he cited that "provides a very plausible path to providing renewable energy cheaper than coal."

Google.org, the search giant's philanthropic arm, is also going to be investing in companies that show the potential to produce energy at an unsubsidized cost lower than coal-fired plants. Makani Power and eSolar, were mentioned as companies Google.org is "working with."

A spokesman for eSolar said the company is not commenting yet on whether it's received an investment from Google.org. Pasadena, CA-based eSolar specializes in solar thermal power, which replaces the fuel in a traditional power plant with heat produced from solar energy. eSolar is headed by serial entrepreneur Bill Gross, who also runs technology incubator Idealab. Idealab recently moved into the renewable energy market with Energy Innovations, a sister company to eSolar that focuses on the retail rooftop solar market.

Gross was unavailable for comment on Google's announcement, but at a recent technology conference, he told InternetNews.com it was important to diversify into alternative energy "for the good of the country."

Makani Power, based in Alameda, CA, is developing high-altitude wind energy extraction technologies. According to the company, high-altitude wind energy has the potential to satisfy a significant portion of current global electricity needs.

Google said it's on track to meet an internal goal it set last spring to be carbon neutral in 2007 and beyond. The company has extensive solar panel installations at its Mountain View, Calif. campus. But last year rival Microsoft announced it had installed the largest solar electric system in Silicon Valley at its facility, also in Mountain View.

Google said RE < C signifies the effort to create renewable energy at a cost less than energy from coal, thus, R(enewable) E(nergy) < C(oal).