Idaho Public Utilities Commission

Case No. PAC-E-11-10, Order No. 32243

June 21, 2011

Contact: Gene Fadness (208) 334-0339, 890-2712



PacifiCorp submits 10-year plan to commission


PacifiCorp, which does business as Rocky Mountain Power in eastern Idaho, plans to meet customer demand over the next 10 years through increased reliance on energy efficiency measures, natural gas plants, market purchases and renewable resource additions. 


The Idaho Public Utilities Commission is taking comment through July 11 on the PacifiCorp’s Integrated Resource Plan, or IRP. The commission requires regulated electric and gas companies to file the plan every two years. Commission acceptance of the IRP does not necessarily mean it endorses all the proposed projects because the plan is based on assumptions and projections that can change over the years. “It is the ongoing planning process that the commission acknowledges, not the conclusions or results,” the commission has stated in previous orders accepting IRP applications.   


Decreases in projected natural gas and wholesale electricity prices favor natural gas-fueled resources and market purchases to meet future load, the company states. The decrease in natural gas prices is due to a boom in nonconventional domestic natural gas discoveries and a robust long-term supply outlook for natural gas.


PacifiCorp expects to need a significant amount of new resources to offset load growth of about 1.8 percent a year and 2 percent growth during peak-use periods in its six-state territory. The most rapid growth is occurring on the east side of its territory which includes about 1 million customers in Utah, Wyoming and Idaho. The utility also needs to replace power generated by the expiration of a number of long-term purchase power contracts.  Without new resources, PacifiCorp anticipates a capacity deficit of 326 MW in 2011 and 3,852 MW by 2020.


Currently, PacifiCorp’s energy mix, which looks at the sources of generation over a year’s time, includes 62.5 percent from coal plants. The proposed IRP reduces use from coal to 36.3 percent in 2020. However, natural gas generation would increase from the current 11.7 percent to 25.5 percent in a decade as would generation from renewable resources (wind, solar and geothermal) from 7.4 percent to 10.7 percent. Generation from energy efficiency and demand reduction programs would increase from 1 percent to 11.3 percent while hydro generation drops from 8.1 percent to 5.2 percent.  Sales agreements from generators other than PacifiCorp would decrease slightly from 7.8 percent to 7.1 percent while purchases from the wholesale market increase from 1.5 percent to 3.2 percent.  


The plan projects these possible resource acquisitions over the next ten 10 years:



n  Acquire 800 megawatts from wind

n  Acquire up to 100 MW from geothermal. A study identified eight potential economically viable geothermal sites in the company’s service territory. 

n  Offset load growth by up to 30 MW from solar generation for hot water heating.

n  Acquire up to 52 MW from combined heat and power resources through PURPA contracts.


Thermal sources:

n  Add 637 MW from Lake Side natural gas plant in Utah County, Utah by July 2014.

n  Issue bids for a natural gas plant late this year or early next year to be in production by summer of 2016. 


Market purchases:

n  Acquire up to 1,400 MW from market purchases or from power purchase agreements through 2014 unless more economical long-term resources become available.


Demand-side management and energy efficiency programs:

n  Offset load growth by up to 1,450 MW by 2020 through conservation programs that reduce demand (250 MW) and energy efficiency programs that reduce consumption (1250 MW).  


Plant efficiency improvements:

n  Gain 31 MW through coal plant turbine upgrade projects in 2011 and 2012 and another 34.2 MW with upgrades completed by 2021.



PacifiCorp plans and builds its transmission system based on 10-year load and resource forecasts. The addition of the Gateway transmission projects will give the company access to diverse resources during a time when national energy policies will continue to push toward renewable and low-carbon resources requirements. PacifiCorp is also required to meet increasingly stringent federal reliability standards.


Comments on PacifiCorp’s IRP are accepted via e-mail through July 11 by accessing the commission’s homepage at and clicking on "Comments & Questions About a Case." Fill in the case number (PAC-E-11-10) and enter your comments. Comments can also be mailed to P.O. Box 83720, Boise, ID 83720-0074 or faxed to (208) 334-3762.

A full text of the company’s plan and appendices is available on the commission’s Web site. Click on “File Room” and then on “Electric Cases” and scroll down to the above case number.