How Section 48E treats commercial battery storage

Battery energy storage is treated as its own category of qualifying property under Section 48E — not as an accessory to a solar array. That distinction matters more than it used to, because storage and solar are now on very different timelines.

Standalone storage no longer has to be charged by on-site solar

Under pre-IRA rules, a battery generally had to be charged predominantly by a co-located renewable system to qualify for the investment tax credit. That requirement is gone. A standalone battery energy storage system (BESS) — including one charged from the grid — can qualify under Section 48E on its own terms.

For a commercial facility, that opens up projects that previously didn’t pencil: demand charge management, backup power for critical loads, and load shifting against time-of-use rates, without requiring a solar array to justify the battery.

Storage was not subject to the wind and solar cutoff

The One Big Beautiful Bill Act (OBBBA) placed a hard deadline on solar and wind: facilities beginning construction after July 4, 2026 are ineligible for Section 48E if placed in service after December 31, 2027.

That placed-in-service deadline does not apply to energy storage technology. Storage remains eligible for Section 48E for projects beginning construction through 2033, after which the credit steps down — 75% of the credit value for construction beginning in 2034, 50% in 2035, and none for construction beginning after 2035.

For a Texas facility weighing solar-plus-storage against storage alone, that gap is now a real planning input rather than a footnote.

What the credit is actually worth

Section 48E carries a base credit of 6% of qualified investment. That base is multiplied by five — reaching 30% — where a project either:

  • satisfies federal Prevailing Wage and Apprenticeship (PWA) requirements, or
  • has a maximum net output below 1 MW-AC, which exempts it from the PWA test

Additional bonus credits may apply for domestic content and for projects sited in qualifying energy communities. Domestic content thresholds were tightened under OBBBA and rise over time.

Being under 1 MW-AC exempts a project from the PWA requirements. It does not make the credit automatic — a separate eligibility test now applies to every project, regardless of size.

The 2026 requirement most commercial buyers haven’t heard about

This is the part worth reading carefully, because it can take a project’s credit from 30% to zero.

OBBBA introduced Prohibited Foreign Entity (PFE) rules, commonly called FEOC requirements. For energy storage projects beginning construction on or after January 1, 2026, the project must clear a Material Assistance Cost Ratio (MACR) — the share of direct equipment cost attributable to suppliers that are not prohibited foreign entities.

The thresholds for energy storage technology:

  • Construction beginning in 2026: at least 55% non-PFE
  • Rising by roughly 5 percentage points each year
  • Construction beginning after 2029: up to 75% non-PFE

Projects that began construction on or before December 31, 2025 are not subject to the material assistance rules. Treasury and the IRS issued initial guidance on calculating the MACR in Notice 2026-15 (February 2026), including safe harbor methods and supplier certification standards.

Why this is a hard test for battery projects specifically

Battery cells account for roughly half of a storage system’s equipment cost under the IRS safe harbor tables, and global cell manufacturing is concentrated in China. A system built around cells from a prohibited foreign entity can fail the material assistance test regardless of where the enclosure, inverters, or balance of system are sourced.

Failing the test does not reduce the credit. It disallows it. A project modeled on a 30% ITC that fails MACR does not fall back to 6% — it receives nothing, and the difference lands on the owner’s balance sheet after the equipment is already bought.

The entity-level and payment rules under the PFE framework apply separately from the material assistance test, and can also affect eligibility.

What this means for procurement

Supply chain decisions are now tax decisions. Practically, that means:

  • Cell sourcing has to be established before equipment is ordered, not during tax preparation. Ownership structure, manufacturing location, and licensing arrangements all factor into PFE status.
  • Supplier certifications need to be collected and retained. Treasury guidance permits reliance on supplier certifications, subject to conditions — but the documentation has to exist.
  • Begin-construction timing carries more weight than it used to, because the threshold rises each year and is fixed by the year construction begins.
  • MACR is calculated per qualified facility, which affects how multi-unit projects should be structured.

This is the kind of requirement that is straightforward when it’s designed in from the start and expensive when it’s discovered late. It’s the same reason we size commercial battery energy storage against a facility’s actual load profile before selecting equipment, rather than specifying hardware first and modeling around it.

Financing mechanics worth knowing

  • Bonus depreciation. 100% bonus depreciation was made permanent for qualified property acquired after January 19, 2025, and energy storage technology retains its five-year property classification under Section 48E.
  • Transferability and direct pay remain available. Credit transferability was preserved under OBBBA, and direct pay remains available to certain entities including nonprofits and state and local governments. For a tax-exempt organization, that is what makes the credit usable at all.

For Texas facilities, the federal picture sits alongside state and utility-level programs — including the Texas property tax exemption under Tax Code Section 11.27, which covers qualifying storage equipment, and utility incentives that vary by service territory.

Where to verify

Federal tax credit eligibility, credit percentage, bonus adders, and foreign entity requirements vary by project and change with statute and guidance. The structure described here is general and is not tax advice. Confirm how these rules apply to a specific installation with a qualified tax advisor before committing capital or equipment orders.

Last verified against published federal guidance: September 14, 2026.

This article describes federal and state incentive programs in general
terms and is not tax, legal, or financial advice. Eligibility, credit
percentages, bonus adders, caps, and supply chain requirements vary by project
and change with statute, regulation, and agency guidance. Rates and program
terms are set by the issuing authority and are subject to change without
notice. Confirm how these rules apply to your specific facility with a
qualified tax advisor before committing capital or placing equipment orders.
NATiVE Solar does not provide tax or legal advice.