Energy Reinvestments in the Intermountain West Can Save Ratepayers Hundreds of Millions

RMI analysis suggests that replacing coal-fired units at Montana's Colstrip Generating Station with a portfolio of solar, wind, and battery storage could save ratepayers $500 million to $1.17 billion over 30 years. The case study urges Northwestern Energy and the Montana Public Service Commission to utilize Energy Infrastructure Reinvestment (EIR) financing and integrated resource planning to transition to affordable, carbon-free energy.

• A managed phaseout of coal-fired power units at Montana's Colstrip Generating Station, replaced by a portfolio of low-cost, carbon-free resources, could save ratepayers between $500 million and $1.17 billion over a 30-year period while maintaining power reliability.
• RMI recommends that Northwestern Energy prioritize stakeholder engagement to leverage financial incentives for coal-to-clean reinvestment in its current rate case and use its upcoming integrated resource plan (IRP) to assess managed phaseout impacts and Energy Infrastructure Reinvestment (EIR) financing.
• The Montana Public Service Commission is urged to direct Northwestern Energy to incorporate EIR financing or securitization strategies into IRP modeling, following precedents set by public service commissions in North Carolina and South Carolina regarding the assessment of federal funding.

APA

Schwartz, A., & Daniel, J. (2025). Energy Reinvestments in the Intermountain West Can Save Ratepayers Hundreds of Millions. RMI. https://rmi.org/resources/energy-reinvestments-in-the-intermountain-west-can-save-ratepayers-hundreds-of-millions-2/

Chicago

Schwartz, Aaron, and Joseph Daniel. Energy Reinvestments in the Intermountain West Can Save Ratepayers Hundreds of Millions. RMI, 2025. https://rmi.org/resources/energy-reinvestments-in-the-intermountain-west-can-save-ratepayers-hundreds-of-millions-2/.

Wikipedia

{{cite report |last1=Schwartz |first1=Aaron |last2=Daniel |first2=Joseph |title=Energy Reinvestments in the Intermountain West Can Save Ratepayers Hundreds of Millions |publisher=RMI |date=6 March 2025 |url=https://rmi.org/resources/energy-reinvestments-in-the-intermountain-west-can-save-ratepayers-hundreds-of-millions-2/ |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{schwartz2025energy, author = {Schwartz, Aaron and Daniel, Joseph}, title = {{Energy Reinvestments in the Intermountain West Can Save Ratepayers Hundreds of Millions}}, institution = {RMI}, year = {2025}, month = mar, url = {https://rmi.org/resources/energy-reinvestments-in-the-intermountain-west-can-save-ratepayers-hundreds-of-millions-2/}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }