San Francisco - Web giant Google unveiled a new national energy plan for the US Wednesday that it said would largely wean the country of fossil fuels by 2030.

The 4.4-trillion-dollar plan was developed by Google's philanthropic arm Google.org, which predicted that the county would reap net savings of 1 trillion dollars over the idea's 22-year term.

The plan called "Clean Energy 2030" was unveiled in an online posting by Jeffery Greenblatt, Google.org's climate and energy- technology manager. It is based on halting the generation of electricity from coal and oil by 2030 and instead relying on power from wind, nuclear and geothermal sources.

It also entails cutting oil use for cars by 40 per cent. It calls for heavy investments in transmission capacity for wind and solar power in the Great Plains and desert Southwest to help cut 88 per cent of fossil fuel use and 95 per cent of carbon-dioxide emissions by 2030.

In addition, the plan calls for tapping geothermal energy as key technologies mature during the next few years.

Specifically, the plan calls for the replacement of all coal- and oil-fired electricity generation with national gas and renewable electricity, including 380 gigawatts of wind power, 250 gigawatts of solar power and 80 gigawatts of geothermal power.

Other elements of the plan include reducing energy use by 33 per cent via energy-efficiency measures, boosting sales of plug-in hybrid vehicles to 90 per cent of new car sales in 2030, increasing the average fuel efficiency of conventional vehicles from 31 miles per gallon to 45 miles per gallon in 2030, and turning over the country's current fleet of vehicles more quickly so that cars are driven only 13 years, instead of an average of 19 years today.

"With a new administration and Congress - and multiple energy- related imperatives - this is an opportune, perhaps unprecedented, moment to move from plan to action," Greenblatt said. "We see a huge opportunity for the nation to confront our energy challenges. In the process we will stimulate investment, create jobs, empower consumers and, by the way, help address climate change."