Google Inc. (NASDAQ: GOOG) and General Electric Co. (NYSE: GE) announced Wednesday that they'll work together to integrate electric vehicles, renewable energy and "smart grid" technologies into the nation's electric grid.

The two companies said they will push these goals both through technology development and by advocating for federal policies they call "critical for building a 21st century U.S. electricity system." The technological push will initially focus on preparing the nation's grid for plug-in vehicles and exploring the potential for "enhanced geothermal technology" to become a major supplier of renewable power, the two companies said.

Google in August said it had invested $10.25 million into three companies working on geothermal technology that injects water deep into the earth to create steam to generate electricity (see Google Funds Hot Rock Technology).

GE and Google also plan to develop enhanced reservoir-visualization systems to allow geothermal resources to be better measured and exploited.

The companies' focus on plug-in vehicles will include developing software, controls and services to help electric utilities manage the new power requirements that may arise if hundreds of thousands of plug-in hybrid or electric vehicles come onto the market in coming years.

As for the policy piece, the companies plan to push for increased transmission capacity to bring more renewable energy to consumers, as well as to build a "smart" electricity grid that will help utilities and their customers use energy more efficiently.

Those smart grid technologies include energy-management systems that can monitor and reduce energy use and so-called "smart meters" that can track and manage power flows remotely.

Google and GE's financial heft may serve them well in their combined push for more smart grid-friendly policies. Google, well known for its information technology expertise, has been a major proponent of solar-friendly policies in Washington D.C., and GE's position as a premiere energy company could add weight to its energy policy prescriptions.

Google and GE didn't elaborate much on how the new partnership will play out beyond its initial technology and policy goals.

"We're not ready to start a broad-based organization to advance this agenda," the companies wrote in a prepared statement. "But we will be looking to work with other companies and organizations" that share similar goals.