Distributed Energy Resources

Western utility’s draft IRP calls for 600 MW of storage by 2025

A draft 2019 resource released by PacifiCorp calls for nearly 600 megawatts of battery storage by 2025 and more than 2,800 MW of battery storage by 2038 and identifies battery storage as part of a least-cost portfolio for the first time.

PacifiCorp subsidiaries serve customers in Oregon, Washington, California, Utah, Idaho and Wyoming.

PacifiCorp on Oct. 3 noted that the draft “preferred portfolio” for the 2019 integrated resource plan (IRP) indicates how the investor-owned company envisions meeting customer energy needs most cost-effectively over the next 20 years. PacifiCorp will file its final 2019 IRP with state regulatory commissions by October 18. 

The plan also calls for nearly 3,000 MW of new solar by 2025, including resources acquired through customer partnerships, and more than 6,300 MW of new solar by 2038.

All of the storage resources planned by 2025 are paired with new solar generation and the plan adds nearly 1,400 MW of stand-alone storage resources starting in 2028.

The new solar and storage resources added over the planning period include:

  • 3,000 MW of new solar in Utah paired with 635 MW of battery storage, phased in between 2020 and 2037;
  • 1,415 MW of new solar in Wyoming paired with 354 MW of battery storage, phased in between 2024 and 2038;
  • 1,075 MW of new solar in Oregon paired with 244 MW of battery storage, phased in between 2020 and 2033; and
  • 814 MW of new solar in Washington paired with 204 MW of battery storage, phased in between 2024 and 2036


The plan also includes more than 3,500 MW of new wind generation by 2025, including resources acquired through customer partnerships, and a total of more than 4,600 MW of new wind generation by 2038, including:

  • More than 1,500 MW of new wind generation that is currently under construction, including new wind projects in Wyoming;
  • 1,920 MW of additional new wind generation in Wyoming by 2024; and
  • 1,100 MW of new wind generation in Idaho in the 2030 to 2032 timeframe

PacifiCorp noted that with respect to the additional renewable resources, total capacity includes 799 MW acquired through customer partnerships supported by purchase of 100% of renewable attributes generated by those resources, resources to be used for renewable portfolio standard compliance, and resources where a portion of the renewable attributes are sold to customers, third parties, or are excluded from energy purchased. 


To facilitate the delivery of new renewable energy resources to PacifiCorp customers across the West, the plan calls for the construction of a 400-mile transmission line known as Gateway South connecting southeastern Wyoming and northern Utah. The new transmission line will be in addition to the 140-mile Gateway West transmission segment in Wyoming currently under construction.

The plan also includes several other transmission upgrades across PacifiCorp’s system that enable new renewables and increase supply reliability and resilience.

Coal unit retirements

Of the 24 coal units currently serving PacifiCorp customers, the draft plan envisions retirement of 16 of the units by 2030 and 20 of the units by the end of the planning period in 2038. The unit retirements will reduce coal-fueled generation capacity by nearly 2,800 MW by 2030 and by nearly 4,500 MW by 2038.

Coal unit retirements scheduled under the resource plan are:

  • Jim Bridger 1 in 2023 instead of 2037
  • Naughton 1 and 2 in 2025 instead of 2029
  • Craig 2 in 2026 instead of 2034
  • Colstrip 3 and 4 in 2027 instead of 2046
  • Jim Bridger 2 in 2028 instead of 2037

The 2019 draft plan also assumes the following units will continue to run until the retirement dates assumed in the 2017 IRP: Naughton 3 (2019); Cholla 4 (2020); Dave Johnston 1-4 (2027); Hayden 1-2 (2030); Huntington 1-2 (2036) and Jim Bridger 3-4 (2037).

The draft preferred portfolio also includes the conversion of Naughton 3 to natural gas in 2020, which will help cost-effectively maintain system reliability as coal units retire and additional renewable resources are added in the near-term.

The draft preferred portfolio and other information about the 2019 IRP can be found here.