Construction Start: What the Storage Credit Clock Means for C&I Portfolios

The distinction that matters

Federal credit eligibility for standalone storage is anchored to when construction starts, not to when a system is energised. Solar and storage have different federal credit deadlines, and credit value depends on the project, its ownership, its construction dates and the eligibility requirements it meets. Qualifying solar that begins construction after July 4, 2026 generally must be placed in service by December 31, 2027; storage follows separate rules. Confirm your own position with your tax adviser against our federal tax credit summary.

For a single site this is a footnote. For a portfolio being sequenced over several years, it is the difference between a schedule that holds its economics and one that does not.

Why this changes sequencing, not underwriting

None of this makes a bad site good. Tariff structure, load shape, interconnection, and site constraints still decide whether a project works. What the credit timeline changes is the order in which viable sites get built, and how much slack a portfolio plan can safely carry.

Practically, that means:

• Sites whose economics depend on the credit should have their construction-start evidence planned deliberately, not assumed.
• Solar-plus-storage scopes and standalone storage scopes may not share the same deadline pressure, so they should be scheduled separately.
• Interconnection timelines, which are utility-dependent and can be long, need to be started early enough that they are not the binding constraint.

What "construction start" requires

Establishing a construction start is a documentation exercise with specific tests, and the details are fact-dependent. It is a question for your tax advisor on each project, not a rule of thumb — we structure and document the project record so that advice has something to work with.

The takeaway for asset teams

Treat the credit as a calendar constraint on a pipeline you have already underwritten on its own merits. Then work backwards: interconnection application, equipment commitments, and construction start each need lead time.

We build the schedule alongside the diagnostic — see how it works or start with a site.