The Portland metro area will now have 475 megawatts (MW) and more than 1.9 gigawatt hours (GWh) of dispatchable capacity thanks to the completion of three new utility-scale battery energy storage systems, according to Portland General Electric (PGE).
During periods of high demand or when electricity is scarce because of inclement weather or unforeseen disruptions, these three plants can together power almost 300,000 houses for four hours. To guarantee that PGE customers have access to energy when they need it most, they also provide flexibility and backup capacity.
“Batteries play an important role in helping PGE build a more flexible, reliable, and diverse generation portfolio,” stated Darrington Outama, PGE Senior Director of Energy Supply. “In addition to providing power during peak hours every day, batteries enhance our ability to respond to sudden changes in the grid and help keep energy supply and demand balanced. For customers, that means more stable and reliable power, all at the lowest possible cost.”
These four-hour lithium-ion battery energy storage systems, which are positioned strategically at important substations in North Portland, Troutdale, and Hillsboro, are incorporated into PGE’s system to better balance electricity production and consumption, thereby lessening grid stress. By lowering PGE’s need for pricey short-term electricity imports, battery storage helps stabilize energy prices, minimizes consumer price volatility, and facilitates the integration of intermittent sources like solar and wind.
The following are two recently opened facilities that Portland General Electric’s 2021 All-Source Request for Proposals (RFP) process successfully designed and awarded to Eolian, L.P. (Eolian):
- Seaside: A 200 MW PGE-owned facility located in North Portland and delivered to PGE by Eolian, L.P. (Eolian) under a fixed-cost Build-Transfer Agreement (BTA). The facility achieved commercial operation in July 2025.
- Sundial: A 200 MW facility in Troutdale, developed by Eolian and operated by NextEra Energy Resources under a 20-year storage capacity agreement with PGE. The facility achieved commercial operation in December 2024.
- Constable: A 75 MW PGE-owned facility located in Hillsboro and constructed for PGE under an engineering, procurement and construction agreement with Mortenson. TThe facility achieved commercial operation in December 2024.
“Battery energy storage systems sited at major substations radically improve the use of existing high voltage transmission lines, avoiding expensive or challenging new grid upgrades and providing a low-cost load growth solution through existing infrastructure,” stated Aaron Zubaty, CEO of Eolian.
IIn 2024, PGE completed the construction of the 17 MW Coffee Creek Battery Storage facility located next to Wilsonville, along with three new large-scale battery installations. With Seaside, Sundial, Constable, and Coffee Creek completed, PGE now has 492 MW of large-scale battery storage capacity.
