Portland General files for accelerated depreciation of its Colstrip coal plant share

Portland General Electric (PGE) on Oct. 12 proposed to the Public Utility Commission of Oregon an automatic adjustment clause to implement the revenue requirement effects resulting from a change in the coal-fired Colstrip Generating Facility currently assumed end-of-life of Dec. 31, 2042, down to Dec. 31, 2030.

During the 2016 Regular session, the Oregon Legislature passed Oregon Senate Bill 1547, the Oregon Clean Electricity and Coal Transition Plan, which was signed into law in March 2016. Among other provisions, SB 1547 requires PGE to double the amount of renewable energy generation under the Renewable Portfolio Standard (RPS) to 50% and to eliminate coal-fired resources from its energy deliveries within the state of Oregon.

SB 1547 requires that electricity provided to Oregon customers by Pacific Power and PGE will be coal-free by 2030. As part of the elimination of coal from PGE’s electricity supply, SB 1547 clearly specifies that the Public Utility Commission of Oregon (OPUC) “shall adjust any schedule of depreciation approved by the commission for an electric company’s coal-fired resource to be fully depreciated on or before December 31, 2030.” This language applies to PGE’s 20% share of Colstrip units 3 and 4, and therefore, PGE must eliminate its use of Colstrip for serving customer loads in Oregon and accelerate the depreciation of the plant to a final retirement date of Dec. 31, 2030.

The Colstrip plant, located east of Billings, Montana, has four coal-fired units capable of producing up to 2,094 MW. Units 1 and 2 began commercial operation in 1975 and 1976, and Units 3 and 4 started in 1984 and 1986. Units 1 and 2 each have about 307 MW of capacity. Units 3 and 4 each have about 740 MW of capacity. The plant is owned by Talen Energy, Puget Sound Energy, Portland General Electric, Avista Corp., PacifiCorp and NorthWestern Energy.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.