2008 Corporate Responsibility Report

How we are creating a smarter foundation for a sustainable future

Delivering Natural Gas

PG&E delivers natural gas to approximately 4.3 million customer accounts in northern and central California. With approximately 6,400 miles of natural gas transmission pipelines and more than 42,000 miles of distribution lines, PG&E operates one of the largest natural gas distribution networks in the country and takes seriously our responsibility to ensure its safety and integrity.

PG&E is a leader in researching ways to expand the use of renewable biogas, a prospect that holds significant potential in a state that is home to two million dairy cows. Last year, PG&E and BioEnergy Solutions began operating the first project in California that is delivering natural gas to a utility using methane produced from animal waste at Vintage Dairy in Fresno County. This highly innovative effort, which produces gas that meets PG&E’s gas quality specifications, is significantly reducing the farm’s methane emissions while providing a valuable resource for our customers. New dairy biomethane projects from BioEnergy Solutions and Microgy will be constructed in 2009, and are expected to be online, delivering gas to PG&E, in 2010.

A PG&E welder bonds a new transition fitting for joining plastic to steel, part of a multi-year project to improve gas service reliability.
Photo: Lewis Stewart

To improve gas service reliability, the company focused on a number of important initiatives last year, including an ambitious, multi-year project to replace aging copper pipelines with more durable polyurethane pipe. The company also took steps to improve and accelerate its routine pipeline integrity surveys with a goal of accomplishing 3 to 4 years of gas system surveying in 16 months.

A potential impact associated with the delivery of natural gas is the release of methane, a greenhouse gas that is at least 21 times more potent on a per ton basis than CO2 in terms of its impact on global warming. As part of our participation in the U.S. EPA’s Natural Gas STAR Partnership, the company avoided the release of more than 770 tons of methane, or approximately 16,200 tons of CO2-equivalent, in 2008.

These savings were achieved primarily by replacing old cast iron and steel gas mains, and by implementing a technique called cross compression, a process by which natural gas is transferred from one pipeline to another during large pipeline construction and repair projects. Cross compression reduces the amount of natural gas vented to the atmosphere by 85 to 90 percent.

In 2008, PG&E also undertook a number of activities that will result in greenhouse gas emission reductions while accomplishing other important objectives. For example, PG&E conducted a focused survey for high-volume gas leaks at our Topock and Kettleman compressor stations. These studies will help identify and repair natural gas leaks faster, which will reduce PG&E’s methane emissions.

Methane Avoided
(Tons CO2-equivalent)