​The first edition of the Modo Energy U.S. BESS Financing Report tracked 12 standalone BESS transactions in Q4 2025, totaling 2.7 GW, 9.8 GWh, and $1.9 billion in disclosed value. The most telling trend wasn't volume. All identified deals exceeded 100 MW, European and Japanese banks swept the top lending positions, and capital began flowing into ISOs beyond ERCOT and CAISO.

This report provides a quarterly snapshot of the US standalone BESS financing landscape. It covers project financing, M&A, and equity investment activity across all major ISOs.

​For any questions on the content in this article, reach out to alex.dediego@modoenergy.com.

Executive Summary

• ERCOT captured 70% of financed BESS capacity, but ISO-NE emerged from zero transactions to 13% of volume as capital expanded into markets with capacity payments
• Every Q4 transaction exceeded 100 MW - smaller projects were shut out of capital markets entirely
• Average project duration rose to 4.6 hours by December, as 4-hour-plus systems become the standard configuration for markets requiring capacity or resource adequacy accreditation
• European and Japanese banks dominated project finance - the top five lenders by capacity were all non-US, led by Nord/LB (435 MW), Deutsche Bank (400 MW), and Natixis (350 MW)
• Greenflash Infrastructure led sponsors at 600 MW, combining financing and M&A across ERCOT

​Which projects closed in Q4 and at what terms?

​Project financing led transaction volume with 1,385 MW across five deals. The largest was Project Soho, a 400 MW, 2-hour system in Brazoria County, Texas, sponsored by Greenflash Infrastructure and financed by Deutsche Bank.

Padua 2 & 3 followed with a combined rated power of 350 MW and 5-hour duration. It was the quarter's longest-duration financed project, backed by Natixis CIB with a $463 million financing package.

​M&A transactions reached 750 MW of volume. Eurowind Energy's acquisition of Potentia-Viridi in Alameda County, California, with 400 MW and 8-hour duration, was the quarter's largest single asset transaction by energy capacity (3,200 MWh).

Equity investment totaled 670 MW. Plus Power closed two ISO New England (ISO-NE) deals on the same day, Cross Town (175 MW) and Cranberry Point (150 MW), both backed by Morgan Stanley tax equity totaling $160 million. GridStor secured $86 million from Foss & Company for the 220 MW Hidden Lakes project in Galveston County.

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​Where did Q4 BESS capital flow?

ERCOT dominated Q4 with 1,555 MW across financing, M&A, and equity investment. ISO-NE followed at 525 MW, driven entirely by project financing and equity investment. CAISO contributed 525 MW through M&A and equity investment, while WECC recorded a single 200 MW financing deal.