Prevalon secures 200MW/800MWh second Idaho BESS project

The BESS is scheduled for operation by 2026 and will use the Prevalon HD 511 battery system. It is powered by a lithium-iron-phosphate (LFP) battery cooled by what Prevalon calls an “energy-dense liquid.” The battery has a rated cycle life of 20 years, and the system includes inverters, medium-voltage transformers, and Prevalon’s “US-made” energy management system (EMS).

This marks the second BESS project Prevalon has secured with Idaho Power. The first BESS, an 82MW/328MWh system, was announced in March 2024 and also included a long-term service agreement with maintenance and remote monitoring.

Idaho Power plans to integrate over 5,000MW of wind and solar as well as 1,100MW of 4-hour energy storage capacity over the next two decades, supporting the IOU’s goal of providing 100% clean energy by 2045.

Speaking with Energy-Storage.news, a representative of Idaho Power said that one reason for adding BESS projects to the company’s portfolio is because of a dramatic increase in demand in its service area in recent years. “In addition to rapid population growth, we have seen the addition of load from new or expanding large commercial and industrial customers.”

Elaborating on what peak periods of electricity use look like in the state and its robust hydroelectric resources, the representative added: “Our annual peak loads typically occur in the summer, driven primarily by air conditioner use and agricultural irrigation. That is the period when BESS installations are the most useful.”

“Typically, our peak hours are in the late afternoon and early evening hours when solar production has dropped off. So, being able to discharge those batteries to help serve load is key. Another key benefit is providing additional flexibility with our hydroelectric system. Idaho Power has significant hydro resources, which provide a third or more of our energy depending on the water year.”

Idaho Power is the state’s largest electric utility and operates 17 hydroelectric plants. The IOU identifies the “backbone” of its hydroelectric systems as the Hells Canyon Complex (HCC). The HCC consists of the Brownlee, Oxbow, and Hells Canyon Dams, collectively providing around 30% of Idaho Power’s total energy generated in a normal water year.

Idaho Power’s representative says that BESS projects will help the IOU hold water for release when it is most beneficial, giving the company greater flexibility to serve load.

Idaho is not part of an ISO or RTO, but the Idaho Public Utilities Commission (IPUC) regulates electricity in the state. In December 2024, Idaho Power submitted an application with the IPUC seeking approval of a certificate of public convenience and necessity (CPCN) to develop 100MW of additional BESS (Premium access article) across two projects after its deal for a 200MW BESS with a 250MW solar facility, with IPP Savion was cancelled (also Premium access article).

Idaho Power’s largest BESS is currently the Hemingway substation, a 40MW project adjoining the Black Mesa solar PV plant. The project was delivered by Powin Energy.

The previously mentioned 82MW/328MWh BESS from Prevalon Energy was the company’s first BESS order after it spun out and rebranded from Mitsubishi Power Americas.

Since then, the company has also been active elsewhere in the Americas, with it and Innergex Renewable Energy agreeing to nearly double the BESS capacity of two sites in Chile in November 2024.

Tom Cornell, Prevalon president and CEO said of the most recently announced deal with Idaho Power: “This continued collaboration reflects the dedication and expertise of our exceptional team at Prevalon.”

“We are proud to be recognised as a trusted partner with extensive project experience in the dynamic field of battery energy storage. We value our partnership with Idaho Power and are excited to further support their long-term goals with our advanced integrated battery energy storage solutions, ensuring a stable and reliable energy grid for their customers.”