Portland General Electric (PGE), the energy generation, transmission and distributor, said it has completed three utility-scale battery energy storage systems (BESS) in Oregon, US.
The projects, which add 475MW in capacity and more than 1.9GWh in duration, can power roughly 300,000 homes for four-hours during peak demand to serve the Portland Metro area.
The BESS projects can also be used when power is limited due to weather or unexpected interruptions with flexibility and backup capacity.
The three lithium-ion BESS are located at substations in North Portland and integrated into its system so that it can reduce strain on the grid by aligning the production and consumption of energy.
This includes:
- The 200MW Seaside BESS project owned by PGE and developed by Eoilian, the energy investment firm owned by BlackRock, under a fixed-cost build-transfer agreement which began commercial operation in July 2025.
- A 200MW BESS project called Sundial that was developed by BESS operator Eoilian and is under a 20-year agreement by NextEra Energy Resources. It went live in December 2024 and is located in Troutdale.
- A PGE-owned 75MW BESS project named Constable and located in Hillsboro. It was built under an engineering, procurement and construction agreement with US-based engineering firm Mortenson and went live in December 2024.
Darrington Outama, senior director of energy supply, PGE, said: “Batteries play an important role in helping PGE build a more flexible, reliable and diverse generation portfolio. 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.”
Image: The PGE-owned 75MW Constable BESS. Credit: PGE.
