Solar and Storage Tax Credits After July 4, 2026: What C&I Projects Need to Know

If your capital plan still assumes a solar-plus-storage package with full federal credits, check the dates first.

What changed for solar and wind

Under Treasury's Notice 2025-42, a wind or solar project that begins construction after July 4, 2026 must be placed in service by December 31, 2027 to keep the credit. The July 4 cutoff has passed. The notice also removed the five percent safe harbor for most projects, so "beginning construction" now means physical work of a significant nature. A purchase order and a spreadsheet no longer count.

What storage still has

Law-firm summaries of the statute put full credit rates in place for storage projects that begin construction through 2033, stepping down after that.

The catch: foreign-content rules

For storage, the share of project cost that must come from non-prohibited sources starts at 55 percent for projects beginning construction in 2026 and rises to 75 percent by 2030. A battery bid that cannot document where its cells, enclosures and power electronics come from is a bid you may not be able to finance.

What this means for a CFO or plant manager

Solar-only is now a race to a 2027 in-service date. If the site has not broken ground, rerun the economics without the credit before you rerun them with it.

Storage economics now depend on the bill of materials as much as the tariff. Ask every vendor for a written material-assistance calculation before you compare prices.

The contrarian point is that for a mid-market manufacturer, the battery may now be the better first project. Demand-charge management and load shifting do not depend on a sunny roof, and the storage credit has the longer life.

This is not tax advice. Have your tax counsel confirm the begin-construction date and the material-assistance calculation before you sign anything.