Portland General Electric (PGE) announced on August 7, 2025, that it has brought a trio of battery energy storage system (BESS) projects online totaling 475 MW/1.9 GWh, to maintain reliability and limit price volatility in the metropolitan area. The three projects bring PGE’s large-scale BESS capacity from 17 MW to 492 MW, representing a significant expansion.
Energy storage plays an important role in helping PGE build a more flexible, reliable and diverse generation portfolio. Along with providing energy during hours of grid stress, BESSs enhance the utility’s ability to respond to sudden changes in the grid and help keep energy supply and demand balanced. As per PGE, BESSs sited at major substations also 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.
The four-hour batteries are strategically located at key substations in Oregon. They will reduce the utility’s need for expensive short-term electricity purchases, and support the integration of intermittent sources like wind and solar. The projects include:
- The 200 MW Seaside project, located in North Portland and developed for the utility by Eolian under a fixed-cost build-transfer agreement. The project began commercial operations in July 2025.
- The 200 MW Sundial project in Troutdale, developed by Eolian and operated by NextEra Energy Resources under a 20-year storage capacity agreement with PGE. Sundial came online in December 2024.
- The 75 MW Constable facility in Hillsboro, which was constructed for PGE under an engineering, procurement and construction (EPC) agreement with Mortenson. The facility achieved commercial operation in December 2024.
Eolian won the Seaside and Sundial projects as part of an all-source request for proposals (RfP) PGE held in 2021. PGE also set up the 17 MW Coffee Creek BESS near Wilsonville, which began operating in 2024.