[Editor's note: This profile is part of an ongoing series spotlighting some of the nominees for the Gigaton Awards, a two-year old recognition program from the Carbon War Room that honors companies for their efforts in measuring, reporting, managing and reducing their greenhouse gas emissions. The winner will be announced Saturday during the U.N climate negotiations in Durban, South Africa.]

Pacific Gas and Electric Co. recently earned recognition for its efforts to boost the energy efficiency of its customers, spending nearly $410 million in 2009 on related programs. All told, these programs have avoided the release of more than 168 million metric tons of carbon dioxide into the atmosphere.

In addition to topping a ranking of 50 of its peers for its energy efficiency investments, the Northern California-based utility has also drawn notice for its carbon footprint, which is significantly smaller than other utilities because of its energy mix of natural gas, nuclear, renewable and hydroelectric. The company uses virtually no coal (1 percent).

Founded in 1852 as the San Francisco Gas Co., it became Pacific Gas and Electric Co. in 1905 through a series of mergers. Its customers now top 15 million.

The company was a supporter of AB 32, the state's landmark climate change law, and it made headlines when it left the U.S. Chamber of Commerce over its opposition to federal climate legislation. PG&E for years also offered its residential customers carbon credits to offset the emissions from the energy use, but recently announced it would end the program in December amid less adoption than first anticipated.

PG&E has also been a big proponent of the smart grid, but its roll-out of millions of smart meters has been met with some resistance from communities and customers. PG&E's history has also experienced controversy, including groundwater contamination that was dramatized in the film "Erin Brockovich" and the tragic natural gas pipeline explosion in San Bruno, Calif., which killed eight people.

Here are the vital statistics for PG&E, which was nominated for a Gigaton Award in the Utilities Category:

Company Name: Pacific Gas and Electric Company
Headquarters: San Francisco
Revenue: $13.84 billion (2010)
CEO: Anthony F. Earley, Jr.
CSO: Steven L. Kline
Sustainability home page: http://www.pgecorp.com/corp_responsibility/reports/2010/sustainability.jsp
Year published first sustainability report: 2004

Greenhouse gas commitments:
Reduce energy use by 25 percent by 2014 (including 4.2 percent at 168 sites in 2011). Meet California's Renewable Portfolio Standard, which mandates that 33 percent of the company's electricity comes from renewable sources by the end of 2020. Comply with the Global Warming Solutions Act of 2006, which aims to reduce greenhouse gas emissions to 1990 levels by 2020.

Other sustainability commitments:
Reduce water use by 20 percent by 2014, (including 5.7 percent at 125 sites in 2011). Increase waste diversion rate to 70 percent by 2014 (including 55 percent at 48 sites in 2011).

Notable achievements:
• Low-Carbon Energy: PG&E supplies electricity and natural gas to about 40 percent of the state's residents. With more than half of electricity coming from renewable or zero-carbon sources, PG&E's overall electricity footprint is about half as carbon intensive as the national average. More than 45,000 PG&E customers have solar PV systems connected to the grid, nearly 30 percent of all U.S. installations.

• Reducing, Measuring Carbon Footprint: The utility met its 2007 goal of reducing sulfur hexafluoride (SF6), a highly potent greenhouse gas, by 60 percent below 1998 levels; by 2010, PG&E had reduced SF6 by 72 percent. PG&E also embarked on an initiative with researchers at U.C. Berkeley and San Francisco-based Climate Earth to measure the greenhouse gas footprint of its supply chain and identify mitigation opportunities, becoming the first utility to do so.

• Smart Grid: PG&E has deployed more than 8.8 million SmartMeter gas and electric meters in Northern and Central California, with a goal of 10 million units by mid-2012. The effort has been marked by resistance in some communities, and a recent report yearned for the company and other utilities in the state to do more to further their smart grid goals.

Underlying image CC licensed by Flickr user Selvig.