Chevrolet Volt enthusiasts know GM is a leader in sustainable transportation, but the company has been on such a creative streak lately, some may not be aware of the extent of it.

Last month GM was ranked number one out of 700 entities that filed clean-energy patents in 2010. Of the 1,881 such patents recorded by the Clean Energy Patent Growth Index of U.S. patents, GM was responsible for 135.

In total, GM received 940 U.S. patents in 2010, placing it in the top 25 of all companies. These patents included those for information technology and consumer electronics.

With regards to clean energy, GM’s patents covered hybrid electric vehicles, fuel cells and solar energy, and focused on improvements to current and future technologies.

General Motors is really ramping up for the future. With 135 clean energy patents received last year, it intends to lead the way.

The Clean Energy Patent Growth Index (CEPGI) 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.

According to CEPGI, automobile companies dominated with six in the top 10 spots. Behind number one GM was Samsung, which took second place due to a number of fuel cell patents. Third place went to Honda, which had been last year's winner. Toyota was fourth with 20 patents, GE was fifth, Nissan sixth, Ford eighth, and Hyundai was ninth.

“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.”

Following is a list of some of the more notable patents GM compiled:

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.

As can be determined by GM’s stated environmental commitment, the company is working to shift away from petroleum dependency. However, even as it develops advanced-tech solutions, this has not stopped it from continuing to refine internal combustion technology as well.

Behind the scenes, GM is researching and developing advanced propulsion technologies for hybrid and electric cars, and alternative sources of energy.

“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,” GM said, “Ultimately, GM believes electrically driven vehicles offer the most long-term benefits to customers around the world.”

As for hybrid, electric and other advanced-tech transportation, the company intends to grow as a world leader, said Alan Taub, GM vice president of global research and development.

“GM is on a journey to reinvent the automotive DNA, and that’s driving a great amount of innovation and technological breakthroughs,” Taub said. “We will continue our aggressive focus on advanced propulsion technologies that will benefit our customers and the environment.”

Note that Taub was quoted yesterday saying the Volt is "on track" with cost cuts and improvements. In light of today's story, it looks all the more likely GM is preparing to be able to back up his assertions with action. will have a substitute writer for tomorrow and may even miss publishing Friday. I'm on assignment at the EDTA Conference in Washington, D.C. - Jeff