Why Battery Storage (BESS) Is Becoming Essential to Solar and Wind Deal Economics Post-OBBBA

The One Big Beautiful Bill Act (OBBBA) imposed a hard deadline on solar and wind developers while providing a much longer runway for battery storage. That distinction is already reshaping project development, financing strategies, and tax credit markets.

To qualify for the full Section 48E Investment Tax Credit (ITC), solar and wind projects must either begin construction by July 4, 2026, or be placed in service by December 31, 2027. Projects that fail to meet either requirement will no longer be eligible for the credit. Energy storage technology, including standalone battery energy storage systems (BESS), was excluded from this accelerated phase-out. BESS projects remain eligible for the full 48E ITC for construction beginning through 2033, followed by a phased reduction to 75% in 2034, 50% in 2035, and zero in 2036.

Those additional years of credit availability create a significant competitive advantage for storage projects. As developers evaluate how to preserve tax credit value and maintain project economics, battery storage is increasingly becoming a central component of project design and financing strategy. As a result, pairing storage with solar and wind is evolving from an optional enhancement into a key driver of project value.

BESS Has the Longest Tax Credit Runway Left

Under the OBBBA, the federal credit landscape for utility-scale renewables splits cleanly into two timelines:

• Solar and wind: Begin construction by July 4, 2026 (with four years to place in service) or be placed in service by December 31, 2027. After that, no §48E ITC.
• Energy storage technology: Full ITC available for construction beginning through 2033, then 75% in 2034, 50% in 2035, 0% in 2036.

For developers with pipelines extending past 2027, BESS is the most certain federal credit available. For developers racing to lock in solar or wind before the cliff, adding storage to the project extends the credit-generating life of the site well beyond the generation-only deadline.

Transferability under Section 6418 is preserved for §48E credits, meaning storage credits remain sellable to corporate buyers. Subject to FEOC restrictions on the buyer, BESS ITCs continue to move through the transferable credit market on familiar terms.

Where BESS Strengthens Deal Economics

Beyond the credit timeline, storage improves the underlying economics of solar and wind projects in ways that are increasingly hard to ignore:

• Shared interconnection and infrastructure. Co-located hybrid projects share transformers, land leases, and interconnection equipment, reducing both upfront capital and ongoing operations costs.
• Curtailment recovery. Storage captures generation that would otherwise be spilled during oversupply periods and dispatches it when prices are higher.
• Revenue stacking. A single BESS asset can serve energy arbitrage, capacity market participation, frequency regulation, and ancillary services — multiple revenue streams from one asset.
• Firmer generation profile. Storage smooths the variability that historically discounted PPAs from intermittent resources, supporting stronger offtake terms.

The net effect is that the same site produces both a longer-lived federal credit stream and a more dispatchable, higher-value energy product.

The Foreign Entity of Concern (FEOC) Trade-Off Storage Developers Should Plan For

BESS does not escape FEOC scrutiny — and in fact faces a higher Material Assistance Cost Ratio (MACR) threshold than solar or wind facilities. Under IRS Notice 2026-15:

• Qualified Facilities (solar and wind): 40% non-PFE cost threshold for construction beginning in 2026, rising to 60% after 2029.
• Energy Storage Technology: 55% non-PFE cost threshold for construction beginning in 2026, rising to 75% after 2029.

The higher threshold reflects the outsized role Chinese suppliers play in battery cells, critical minerals, and module assembly. For developers, that means earlier and more rigorous supply chain diversification, supplier certifications under penalties of perjury, and MACR documentation that can withstand the six-year IRS audit window. The longer credit runway is real — but only for projects that can document a clean supply chain.

What This Means for the Transferable Credit Market

As wind and solar credit production compresses into a narrow 2026–2027 window while storage credit generation remains available through 2033 and beyond, BESS is expected to represent an increasingly larger share of the transferable tax credit market. Corporate buyers developing multi-year credit acquisition strategies are already incorporating storage credits into their forward-looking pipelines.

For sellers, this means storage credits should be priced, documented, and structured with the same level of diligence that has long applied to solar and wind ITCs. At the same time, storage transactions require additional attention to FEOC-specific representations, Material Assistance Cost Ratio (MACR) documentation, and supplier certifications, all of which should be addressed early and incorporated into the transfer agreement from the outset.

How Fallbrook Approaches BESS Transactions

Fallbrook has facilitated transferable tax credit transactions across a variety of sectors for more than two decades, and storage credits sit squarely within our core renewable energy tax credit practice. On every BESS transaction, we work closely with developers and buyers to evaluate project eligibility, coordinate diligence efforts, and structure transfer agreements that help address key transaction risks and compliance considerations.

For developers pivoting toward storage as the OBBBA reshapes their pipeline, and for buyers building forward credit programs that extend past the 2027 solar and wind cliff, Fallbrook is positioned to facilitate the transactions that move these credits to the corporate balance sheets that need them.

Talk to Fallbrook About Your BESS Credit Strategy

To learn more, email: team@fallbrookfinancial.com, with the subject line, “Meet with Louis!”


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Sources & Further Reading

This article draws on the OBBBA statutory text, IRS guidance, and analysis published by leading tax and energy law firms.

Primary Guidance

• One Big Beautiful Bill Act (OBBBA), Pub. L. 119-21 (July 4, 2025). https://www.congress.gov/bill/119th-congress/house-bill/1
• IRS Notice 2026-15 (February 12, 2026) — Interim guidance on material assistance and the MACR framework. https://www.irs.gov/pub/irs-drop/n-26-15.pdf
• IRS Notice 2025-42 (August 15, 2025) — Beginning of construction guidance. https://www.irs.gov/pub/irs-drop/n-25-42.pdf
• Internal Revenue Code §§ 48E, 6418, and 7701(a)(52). https://www.law.cornell.edu/uscode/text/26

Law Firm and Advisory Analysis

• Arnold & Porter: “From IRA to OBBBA: A New Era for Clean Energy Tax Credits.” https://www.arnoldporter.com/en/perspectives/advisories/2025/07/from-ira-to-obbba-a-new-era-for-clean-energy-tax-credits
• Morgan Lewis: “How FEOC Rules Are Reshaping Energy Storage Tax Credit Eligibility” (March 13, 2026). https://www.morganlewis.com/pubs/2026/03/how-feoc-rules-are-reshaping-energy-storage-tax-credit-eligibility
• Steptoe: “The One Big Beautiful Bill: Impact on the IRA’s Clean Energy Tax Credits” (July 23, 2025). https://www.steptoe.com/en/news-publications/the-one-big-beautiful-bill-impact-on-the-iras-clean-energy-tax-credits.html
• Winston & Strawn: “One Big Beautiful Bill – Solar and Wind PTCs and ITCs.” https://www.winston.com/en/blogs-and-podcasts/tax-impacts/one-big-beautiful-bill-solar-and-wind-ptcs-and-itcs
• FBT Gibbons: “One Big Beautiful Bill Act Cuts the Power” (August 4, 2025). https://fbtgibbons.com/one-big-beautiful-bill-act-cuts-the-power-phase%E2%80%91outs-foreign%E2%80%91entity-restrictions-and-domestic-content-in-clean%E2%80%91energy-credits/
• RSM US: “Tax Bill Significantly Changes Clean Energy Credits and Incentives.” https://rsmus.com/insights/services/business-tax/obbba-tax-clean-energy.html
• Grant Thornton: “Energy Incentives Under OBBBA: What You Need to Know” (September 5, 2025). https://www.grantthornton.com/insights/alerts/tax/2025/insights/energy-incentives-under-obbba-what-you-need-to-know
• Norton Rose Fulbright (Project Finance NewsWire): “Q&A – Fuel cell projects eligible for ITC under section 48E.” https://www.projectfinance.law/tax-equity-news/qa-fuel-cell-projects-eligible-for-itc-under-section-48e

Industry and Trade Press

• Modo Energy: “Unpacking the OBBBA and Its Impact on Project Development Timelines and CapEx” (August 28, 2025). https://modoenergy.com/research/en/obbba-2025-project-timelines-capex-bess-wind-solar-construction-safe-harbor-ercot-caiso-pjm-nyiso-isone-miso-trump
• PowerFlex: “Navigating the OBBBA and Preserving ITC Value for Solar & Storage Portfolios.” https://www.powerflex.com/blog/navigating-the-obbba-and-preserving-itc-value-for-solar-storage-portfolios

Disclaimer: This article reflects guidance available as of July 2026, including the OBBBA, IRS Notice 2026-15, and IRS Notice 2025-42. Treasury and the IRS are expected to issue further guidance throughout 2026. Nothing in this article constitutes legal or tax advice. Project sponsors and credit buyers should consult qualified tax counsel before structuring any credit transfer.