By rule, (WAC 480-100-238) and (WAC 480-90-238), all natural gas and electric utilities regulated by the commission are required to develop plans for how they will obtain future energy resources for their customers. A Least Cost Plan or Integrated Resource Plan is used to identify a utility company's long-term energy resource strategy. These plans describe how the company will meet future customer needs at the least cost to ratepayers. Utility companies are required to update their plans every two years. The UTC completed a review of its rules for least cost plans in 2006.

Link to Avista's 2007 Integrated Resource Plans
http://www.avistautilities.com/inside/resources/IRP/pages/default.aspx


Link to Northwest Natural's 2009 Least Cost Plan
https://www.nwnatural.com/content_aboutus.asp?id=480


Link to PacifiCorp's 2008 Integrated Resource Plan
http://www.pacificorp.com/Navigation/Navigation23807.html


Link to Puget Sound Energy's 2009 Least Cost Plan
http://pse.com/energyenvironment/energyresourceplanning.aspx


Link to Cascade Natural Gas 2008 Integrated Resource Plan -
http://www.cngc.com/_docs/Cascade_Natural_Gas_2008_IRP.pdf

Staff contact: Deborah Reynolds at (360) 664-1255 or by e-mail: dreynold@wutc.wa.gov