The Gas Transmission Northwest Pipeline, formerly known as the Pacific Gas Transmission Pipeline, has been operating as one of the largest and most important natural gas pipelines in the western portion of North America since 1961.

The TransCanada-owned system stretches 1,356 miles from the British Columbia-Idaho border through Washington to the Oregon-California border with a capacity of 2.9 billion cubic feet per day (Bcf/d). The system has the capacity to deliver more than 2.1 Bcf/d of natural gas to California and up to 1 Bcf/d to the Pacific Northwest. It is powered by 12 compressor stations with 513,400 horsepower. According to TransCanada, the volumes shipped on the pipeline primarily come from Western Canada, but additional volumes from the U.S. are received at Stanfield, Ore.

The pipeline has interconnections with TransCanada’s BC System at Kingsgate, British Columbia; Williams’ Northwest Pipeline at Spokane and Palouse, Wash., and Stanfield, Ore.; and the Pacific Gas & Electric Co. and Tuscarora Gas Transmission Co. at Malin, Ore.

As natural gas becomes more important on the West Coast as a fuel for both electric power generation and transportation, the Gas Transmission Northwest system will increase in value. The system is already benefiting from the increase of natural gas production out of Western Canada, but it will further benefit as production is added from the Mackenzie Delta and Alaska.

According to Hart Energy’s Mapping & Data Services, the largest transportation customer on the system is Pacific Gas & Electric Co. at 610,000 dekatherms per day (Dth/d). This is followed by Avista Corp. at a combined 245,000 Dth/d; EDF Trading North America at 150,000 Dth/d; Shell Energy North America at 139,000 Dth/d; Northwest Natural Gas Co. at 106,000 Dth/d; Puget Sound Energy at 90,000 Dth/d; IGI Resources at 85,000 Dth/d; Iberdrola Renewables at 80,000 Dth/d; and Sierra Pacific Power Co. at 80,000 Dth/d.

In the four-year period from 2006 to 2009, the system’s best year for transportation revenue was 2007 at $300 million. This was also the system’s best year for throughput volumes at 2.3 million Dth/d

Contact the author, Frank Nieto, at fnieto@hartenergy.com.