Search-engine leader Google Inc. plans to spend heavily to develop electricity from renewable energy sources that will be cheaper than electricity produced from coal. It hopes to spark innovation in alternative technologies such as solar, wind and geothermal. At the same time, it is ramping up efforts to accelerate adoption of plug-in hybrid electric vehicles.

Google acknowledges that reducing its huge electricity bills and potentially profiting from licensing fees are among its goal, but insists its primary motivation is improving the environment. Google wants to "spark a green electricity revolution that will deliver breakthrough technologies priced lower than coal," a company spokesman says.

Google has not revealed many details about its plans, but alternative energy experts say its actions are significant because they establish a firm goal, making renewable energy cost-competitive with coal.