Clean Energy's Closing Window: OBBBA's Accelerated Credit Terminations and the Race to Begin Construction

The consumer credits end first

The fastest-moving terminations are the ones individuals will notice. The One Big Beautiful Bill Act (OBBBA), Public Law 119-21, signed July 4, 2025, set hard end dates for the consumer-facing credits, and the IRS confirmed them in a public set of frequently asked questions issued in August 2025.

• The clean vehicle credits end after September 30, 2025. This covers the new clean vehicle credit under IRC § 30D (up to $7,500), the used clean vehicle credit under § 25E (up to $4,000), and the commercial clean vehicle credit under § 45W. Vehicles acquired after September 30, 2025 do not qualify. The IRS has indicated a vehicle is generally treated as acquired when a written binding contract is entered into and a payment is made — even a nominal deposit or trade-in — on or before that date, which can matter when delivery runs later.
• The residential clean energy credit under IRC § 25D — the 30 percent credit for rooftop solar, battery storage, geothermal, and similar improvements — ends for expenditures made after December 31, 2025. Under prior law this credit ran through 2034; OBBBA accelerated its termination by roughly nine years.
• The energy-efficient home improvement credit under IRC § 25C ends for property placed in service after December 31, 2025.

For households weighing an electric-vehicle purchase or a solar installation, this compresses a multi-year decision into the current quarter. The vehicle credit, in particular, turns on action by September 30; the residential credits, on completion by year-end.

The big credits hinge on a begin-construction date

For developers, the consequential change is to the tech-neutral credits — the clean electricity production credit under IRC § 45Y and the clean electricity investment credit under IRC § 48E — and specifically to how they now treat wind and solar.

For applicable wind and solar facilities, OBBBA imposes an accelerated deadline with two alternative paths. A facility remains eligible if it either begins construction on or before July 4, 2026 — within twelve months of enactment — or is placed in service by December 31, 2027. Meeting either prong preserves the credit; missing both ends it. In practical terms, a wind or solar project that can break ground within the next several months protects its eligibility under the begin-construction prong; a project that cannot must instead race to be operational by the end of 2027.

Other tech-neutral resources are treated differently, and developers should not assume the wind-and-solar cliff applies to everything. Energy storage, geothermal, nuclear, and similar technologies are not subject to that accelerated deadline. They retain a longer phase-down keyed to the year construction begins — broadly, full credit for facilities beginning construction through 2033, then stepping down to 75 percent in 2034, 50 percent in 2035, and zero in 2036. The headline cliff is a wind-and-solar event; the rest of the tech-neutral landscape steps down on a longer schedule.

Layered on top, beginning in 2026, are new restrictions tied to prohibited foreign entities — sometimes described as foreign-entity-of-concern rules. These disqualify credits in cases of certain foreign ownership or control, and impose material-assistance cost-ratio requirements for facilities beginning construction in 2026 and later. The detailed thresholds were still being developed in guidance, but the existence of these restrictions, and their arrival in 2026, are settled enough to plan around: projects starting in 2026 face a supply-chain compliance layer that 2025 projects do not.

What "begin construction" now requires

Because so much turns on beginning construction by July 4, 2026, the standard for what counts has become the whole game — and that standard tightened in 2025.

In Notice 2025-42, issued August 15, 2025, Treasury and the IRS set out begin-construction rules for wind and solar under the new regime. The notice eliminated the long-standing five percent safe harbor for most wind and solar facilities — the rule under which incurring five percent of project cost could establish that construction had begun — preserving it only for smaller solar facilities at or below 1.5 megawatts. For most projects, beginning construction now means satisfying the physical work test: physical work of a significant nature. The notice applies to facilities that do not begin construction before September 2, 2025.

The consequence for developers is that paper safe harbors are no longer the easy path to locking eligibility. Establishing begin-construction status for a wind or solar project against the July 4, 2026 deadline will, in most cases, require genuine physical work — which means real lead time for engineering, procurement, and mobilization, not a last-minute cost commitment.

How to read the landscape

The unifying theme is that the IRA's open-ended runway is gone and has been replaced by near-term deadlines that now drive every clean-energy decision. The right response differs by who is acting.

A household should treat the consumer credits as expiring on their stated dates: vehicles by September 30, 2025, residential improvements by December 31, 2025. There is no phase-down softening these; they end.

A developer with a wind or solar project should be making a begin-construction decision now, against the July 4, 2026 deadline and the tightened physical-work standard, with the December 31, 2027 placed-in-service path as the fallback. A developer in storage, geothermal, or nuclear has more time but should still map projects against the longer phase-down and the 2026 foreign-entity restrictions. In every case, the planning variable that matters most is no longer the credit rate. It is the calendar.

Key takeaways

• OBBBA (Pub. L. 119-21) terminates the clean vehicle credits (IRC §§ 30D, 25E, 45W) for vehicles acquired after September 30, 2025.
• The residential clean energy credit (§ 25D) and the energy-efficient home improvement credit (§ 25C) end for 2025 — expenditures after December 31, 2025 do not qualify.
• For wind and solar, the tech-neutral credits (§§ 45Y, 48E) require beginning construction by July 4, 2026, or being placed in service by December 31, 2027; other resources follow a longer phase-down through 2036.
• Notice 2025-42 (Aug. 15, 2025) eliminated the five percent safe harbor for most wind and solar, making the physical work test the operative begin-construction standard.

Frequently asked questions

Is the $7,500 EV credit still available?

Only for vehicles acquired on or before September 30, 2025. The credit terminates for vehicles acquired after that date, and a binding contract with a payment by then is generally what establishes acquisition.

I'm planning rooftop solar. Do I still get the 30 percent credit?

Only if the expenditures are made on or before December 31, 2025. The residential clean energy credit terminates for expenditures after that date, roughly nine years earlier than under prior law.

My wind project can't begin construction by mid-2026. Is the credit lost?

Not necessarily. Wind and solar facilities have an alternative path: if construction does not begin by July 4, 2026, the facility can still qualify by being placed in service by December 31, 2027. Beginning construction now generally requires meeting the physical work test under Notice 2025-42.

Bottom line

The clean-energy credits have shifted from a long runway to a set of imminent deadlines. Households should act within the current quarter on vehicles and by year-end on home improvements; developers should make begin-construction decisions now, under a tighter standard, against a July 2026 wind-and-solar deadline. The credit rate is no longer the variable to watch — the date is.