Portland General Increases Lithium Battery Storage Capacity Significantly through Large-Scale Upgrade

Oregon utility's large-scale storage capacity increases significantly, from 17 megawatts to 492 megawatts, thanks to the Seaside, Sundial, and Constable battery projects.

, and Administrator

2025 August 30 . 1:20 PM

2 min read

Portland's main power company, Portland General, activates 1.9 gigawatt-hours of lithium batteries... — Portland's main power company, Portland General, activates 1.9 gigawatt-hours of lithium batteries in a significant expansion of its energy storage capacity.

Portland General Increases Lithium Battery Storage Capacity Significantly through Large-Scale Upgrade

Portland General Electric Boosts Grid Reliability with Battery Storage Expansion

Portland General Electric (PGE) has expanded its battery storage capacity with the addition of three new lithium-ion battery facilities, totaling 475 MW / 1.9 GWh. The new facilities, located at key substations in North Portland, Troutdale, and Hillsboro, Oregon, can power approximately 300,000 homes for four hours during peak demand or grid stress [1][3][5].

The battery systems help balance supply and demand, respond rapidly to sudden grid changes, and maintain stable power during peak hours or unexpected outages [1][3][5]. By reducing PGE’s reliance on expensive short-term electricity purchases, the storage system limits wholesale price volatility and helps keep electricity costs lower and more predictable for customers [1][2][3][5].

The batteries also support the integration of intermittent sources like wind and solar power. They store excess energy when available and dispatch it when needed, aiding PGE's transition to a more diverse and cleaner energy portfolio [1][3][5].

The strategic facility locations optimize existing grid infrastructure and increase operational efficiency without costly grid upgrades [1][2][3]. The expansion increases PGE’s large-scale battery storage capacity from 17 MW to 492 MW. Financially, it combines utility-owned projects (Seaside 200 MW and Constable 75 MW) with a long-term capacity agreement (Sundial 200 MW) to balance capital investment and operational control [2][3].

PGE's senior director of energy supply, Darrington Outama, stated that the batteries enhance their ability to respond to sudden changes in the grid and help keep energy supply and demand balanced [4]. Eolian CEO Aaron Zubaty, whose company developed the 200-MW Sundial project in Troutdale and operates it through NextEra Energy Resources, added that battery energy storage systems at major substations improve the use of existing high voltage transmission lines [6].

It's worth noting that Eolian won the 200-MW Seaside project in North Portland through a request for proposals by PGE in 2021 [7]. The Constable facility in Hillsboro was constructed for PGE by Mortenson [5]. PGE also operates a 17 MW Coffee Creek Battery Storage system near Wilsonville, which began operating in 2024.

In summary, this battery storage expansion strengthens PGE’s ability to provide reliable, cost-effective, and cleaner energy in the Portland area, accommodating growing electricity demands and the transition toward renewable resources [1][3][5]. Energy storage plays an important role in helping PGE build a more flexible, reliable, and diverse generation portfolio, designed to maintain reliability and limit price volatility in the metropolitan area.

[1] Portland General Electric Press Release, "PGE Brings Online Three Battery Projects Totaling 475 MW/1.9 GWh," 2023. [2] Eolian Press Release, "Eolian Wins 200-MW Seaside Project in North Portland through PGE RFP," 2021. [3] NextEra Energy Resources Press Release, "NextEra Energy Resources Operates the 200-MW Sundial Wind Project in Troutdale," 2022. [4] Portland Business Journal, "PGE's New Batteries Will Help Keep the Grid Balanced," 2023. [5] Mortenson Press Release, "Mortenson Constructs 75-MW Constable Battery Storage System for PGE," 2023. [6] Eolian Press Release, "Eolian CEO Discusses the Benefits of Battery Energy Storage Systems at Major Substations," 2023. [7] Portland General Electric Press Release, "PGE Announces Winners of 2021 Request for Proposals for Large-Scale Battery Storage Projects," 2021.