While the smart people at Google (GOOG) are figuring out search, cloud computing, mobile operating systems, Web browsers, etc., its philanthropic arm, Google.org, is hard at work trying to save the world. Their latest: An ambitious plan for how the U.S. can cut energy consumption, switch to clean power sources, and reduce our reliance on foreign oil.

Google has published the entire document at Google Knol -- now we see what it's for! -- including charts and an economic analysis: "Although the cost of the Clean Energy 2030 proposal is significant (about $4.4 trillion in undiscounted 2008 dollars), savings are even greater ($5.4 trillion), returning a net savings of $1.0 trillion over the 22-year life of the plan."

What sort of stuff needs to happen to achieve these results? From Google's plan:

Deploying aggressive end-use electrical energy efficiency measures to reduce demand 33%.

Replacing all coal and oil electricity generation, and about half of that from natural gas, with renewable electricity.

Increasing plug-in vehicles (hybrids & pure electrics) to 90% of new car sales in 2030, reaching 42% of the total US fleet that year.

Increasing new conventional vehicle fuel efficiency from 31 to 45 mpg in 2030.

Accelerating the turnover of the vehicle fleet from 19 to 13 years (resulting in 25 million new vehicle sales per year in 2030, a 31% increase over the baseline).

Will any of this happen? We don't know, of course, but Google could at least achieve its goal to "stimulate debate" with the new plan.

It's also a hopeful look ahead for some of its investments: Google has invested some $45 million in startups designing wind, solar, and geothermal power technologies this year, according to Reuters.

See Also: Where Are They Now? A Decade Of Google Products And Deals You've Forgotten About