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. Standalone storage retains a 30% investment tax credit for construction starts through 2033, while the solar timeline is tighter.

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.