Idaho Power’s updated integrated resource plan adds more solar, wind and energy storage than gas generation, while Public Service Company of New Mexico gets 450MW of solar and storage added to its resource application.
Idaho Power looks to renewables to address peak demand
Investor-owned utility (IOU) Idaho Power’s 2025 integrated resource plan (IRP) includes three times as much solar, wind and energy storage as new gas generation.
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Idaho Power filed its 20-year energy plan with state regulators on 27 June. The public utility commissions of Idaho and Oregon will set a schedule for public review and comment before the plan is officially acknowledged.
Over the next 20 years, the company’s peak demand is projected to increase by nearly 45% or 1,700MW, with almost 1,000MW of that growth occurring within the next five years.
That 5-year increase in demand is nearly 50% more than the capacity of the company’s single largest energy source, the Brownlee hydropower plant.
To address this increasing demand, the IRP incorporates a substantial amount of affordable resource types:
1,445MW of solar, 885MW of battery storage, 700MW of wind, 611MW of converted coal to gas, 550MW of new gas, 344MW of energy efficiency and 20MW of incremental demand response.
Additionally, the IRP emphasises the importance of expanding transmission infrastructure, particularly through the Boardman to Hemingway and Southwest Intertie projects. These are 500-kilovolt lines designed to allow the company to import electricity during periods of high customer demand.
Idaho Power also says its preferred portfolio of resources focuses on the least-cost and reducing wildfire risk.
In Idaho Power’s IRP, the IOU details its current plant capacity, totalling 3,704MW.
Of this figure, 300MW is comprised of battery energy storage systems (BESS). This includes the Happy Valley BESS, Hemingway, Black Mesa, Franklin and other distributed BESS projects.
Idaho is unique in its large-scale use of hydroelectric energy generation. Notably, Idaho Power’s plant capacity includes 1,818.4MW from hydroelectric projects.
The utility also considered several types of energy storage technologies and modelled battery storage based on lithium-ion (Li-ion), iron-air technology and pumped hydro storage.
While the IRP notes that it will continue to evaluate other types of energy storage technology, the 2025 IRP modelled Li-ion for short—and medium-duration storage.
Idaho Power has modelled multi-day duration storage on iron-air batteries, similar to that developed by Form Energy, and says that the downside of the technology is a lower round-trip efficiency compared to Li-ion.
Mitch Colburn, Idaho Power Vice President of Planning, Engineering, and Construction, said of the IRP:
“Our plan really highlights the work we are doing to identify resources that will provide safe, reliable energy for our customers at the lowest cost over the long term. We look at a wide range of potential resources that will serve all of our customers well into the future.”
Public Service Company of New Mexico gets solar and storage stipulation approved
In other IOU-related news, Public Service Company of New Mexico’s (PNM’s) stipulation filed in its 2028 resource application has been approved by the New Mexico Public Regulation Commission (NMPRC).
PNM filed the stipulation in March to increase solar and storage capacity, including the addition of 300MW capacity through energy storage agreements (ESAs) for two 150MW standalone battery storage facilities and the addition of a 150MW solar and battery storage facility (100MW solar, 50MW battery storage), to be owned and operated by PNM. The latter includes the proposed option to increase the battery storage by an additional 20MW.
In total, the approved resources will add 450MW of new solar and battery storage capacity in 2028. The utility also sought extension of a 167MW natural gas power purchase agreement (PPA) with plant operator Valencia Power through 2039. The current agreement between the pair expires in 2028.
PNM notes this will continue progress toward the zero-carbon requirements of New Mexico’s Energy Transition Act (ETA).
Enacted in 2019, the ETA set a statewide renewable energy standard of 50% by 2030 for New Mexico IOUs and rural electric cooperatives.
The ETA has additional goals of 80% by 2040 and setting zero-carbon resources standards for IOUs by 2045 and rural electric cooperatives by 2050.
PNM is a wholly owned subsidiary of TXNM Energy. TXNM had pledged to achieve 100% carbon-free power generation by 2040 across its subsidiaries. Earlier this year, Texas-New Mexico Power (TNMP), another TXNM subsidiary, entered into an interconnection agreement for a BESS with developer-operator Jupiter Power.
TXNM Energy is currently the target of an acquisition by Blackstone Infrastructure, which values the energy company at US$11.5 billion.
