DETROIT, April 15, 2011 /PRNewswire/ -- General Motors received more clean-energy patents last year than any other organization, according to the Clean Energy Patent Growth Index of U.S. patents. GM's 135 patents represent nearly 14 percent of the total 1,881 received by 700 entities.

"U.S. clean-energy patents were at an all-time high in 2010," said Victor Cardona, co-chair of the Cleantech Group at Heslin Rothenberg Farley & Mesiti, publisher of the index. "GM has clearly put forth a lot of effort in a range of clean-energy technologies, resulting in its appearance at the top of the list for the first time."

The Clean Energy Patent Growth Index tracks the granting of U.S. patents in solar, wind, hybrid/electric vehicles, fuel cells, hydroelectric, tidal/wave, geothermal, biomass/biofuels and clean, renewable energy.

GM's patents covered hybrid electric vehicles, fuel cells and solar energy, and focused on improvements to current and future technologies. Here are a few of last year's inventions.

• Multi-injection combustion cycle systems for spark ignition direct injection engines: Improves fuel and air mixing, and reduces hydrocarbon emissions during engine startup and cranking.
• Dynamically adaptive method for determining a battery's state of charge: Improves fuel economy with a new algorithm that estimates a lithium-ion battery's internal parameters in real time.
• Electrically variable transmission having three planetary gear sets with two fixed interconnections: Ultra-efficient hybrid electric vehicle transmission design that features low electrical losses, high torque capacity and city and highway modes.
• Variable active fuel management delay with hybrid start-stop: Control system that seamlessly integrates active fuel management with start-stop for additional fuel savings.
• Control of hybrid power regeneration during cruise control: Uses regenerative braking so the onboard battery can be charged during vehicle operation, saving fuel.
• Method of operating a plug-in hybrid electric vehicle: Involves operating a heater when the vehicle is cold to preheat the battery, improving electric driving range.

"GM is on a journey to reinvent the automotive DNA, and that's driving a great amount of innovation and technological breakthroughs," said Alan Taub, GM vice president of global research and development. "We will continue our aggressive focus on advanced propulsion technologies that will benefit our customers and the environment."

GM received 940 U.S. patents in 2010, placing it in the top 25 of all companies. This includes sectors such as information technology and consumer electronics.

"Strong companies today are driven by a culture of innovation fueled by a continued commitment to R&D investment," said James E. Malackowski, chairman and CEO of Ocean Tomo, an Intellectual Capital Merchant Banc® firm. "These companies are usually leading the way in next-generation technologies like clean and renewable energy."

GM believes energy alternatives and advanced technologies that help reduce dependency on petroleum, improve fuel economy and reduce emissions are keys to developing sustainable transportation. The company is pursuing several options to best meet the needs of customers around the world – from gasoline, diesel, and biofuels to electrically driven vehicles such as hybrids, electric vehicles with extended range and hydrogen fuel cell vehicles. Ultimately, GM believes electrically driven vehicles offer the most long-term benefits to customers around the world.

General Motors (NYSE: GM, TSX: GMM), one of the world's largest automakers, traces its roots back to 1908. With its global headquarters in Detroit, GM employs 202,000 people in every major region of the world and does business in more than 120 countries.  GM and its strategic partners produce cars and trucks in 30 countries, and sell and service these vehicles through the following brands: Baojun, Buick, Cadillac, Chevrolet, GMC, Daewoo, Holden, Isuzu, Jiefang, Opel, Vauxhall, and Wuling. GM's largest national market is China, followed by the United States, Brazil, the United Kingdom, Germany, Canada, and Italy.  GM's OnStar subsidiary is the industry leader in vehicle safety, security and information services.  More information on the new General Motors can be found at www.gm.com.

SOURCE General Motors