The 2027 Solar Tax Credit Deadline: A Floating Solar Timeline That Still Works

If a commercial floating solar project on your pond did not begin construction by July 4, 2026, the federal clock on it is now simple and unforgiving: to claim the Section 48E Investment Tax Credit, the system has to be placed in service by December 31, 2027. That is roughly fifteen months from today.

Fifteen months sounds like plenty. For a land-based array that still needs a site, entitlements and grading, it often is not. For a floating array on a pond you already own, it is very workable, if you start now and plan backward from the deadline.

This post walks through what the rules say, what they mean for a pond project, and a realistic timeline that still gets you there. It is general information, not tax advice. Confirm your project's eligibility with a tax professional before you commit.

What changed, in plain English

The One Big Beautiful Bill Act, signed July 4, 2025, put an end date on the commercial solar credits (Section 48E for the investment credit and Section 45Y for the production credit). Solar projects now fall on one of two tracks:

Treasury tightened the "begin construction" rules in Notice 2025-42. For projects above 1.5 MW, the old 5% cost safe harbor went away and only the physical work test counts. Solar facilities of 1.5 MW (AC) or less kept the 5% option. But since July 4, 2026 has passed, that distinction no longer helps a new project. If you had not started by then, the only question left is whether you can be in service by the end of 2027.

The residential credit (Section 25D) is a separate story. It ended for expenditures after December 31, 2025, per the Congressional Research Service. This post is about commercial, municipal, agricultural and multi-family projects that claim 48E.

The second hurdle: FEOC material assistance

Projects that begin construction after December 31, 2025 also have to clear the new "prohibited foreign entity" material assistance rules. Under Treasury's interim guidance in Notice 2026-15, as summarized by pv magazine USA, a solar facility starting construction in 2026 needs a material assistance cost ratio of at least 40%. In other words, at least that share of the facility's manufactured-product costs has to come from non-prohibited sources. The threshold rises in later years.

Modules and inverters dominate that calculation, so they deserve the most scrutiny. Every other manufactured component needs documented sourcing too. How racking and floats are treated in the ratio depends on how they are classified, so ask your tax advisor to confirm. We cover what documentation to request from every supplier, including us, on our FEOC compliance page.

Why a pond is a head start

The projects most likely to miss December 31, 2027 are the ones still waiting on land. A floating array skips several of the slowest steps:

• No land acquisition or lease. The water surface is already yours.
• No grading, piles or ground-screw geotech. The array floats and is anchored or moored.
• Often a shorter permitting path. Since Sackett v. EPA (2023), many privately owned, isolated retention, irrigation and process ponds sit outside federal Clean Water Act jurisdiction. That can mean no Army Corps Section 404 or Section 10 permit. It does not mean no permits. Local building, electrical and interconnection approvals always apply, and jurisdiction depends on the specific water body and your state. Our permits and jurisdiction guide explains how to tell.
• Kit-based installation. Gen3 structure kits ship as complete float, rail and mounting packages. On a non-jurisdictional pond, installation typically runs weeks, not months.

A backward timeline to December 31, 2027

Work backward from the deadline, not forward from today. The steps below are the order that matters. Durations vary a lot by utility and county, so get real dates for your site early.

1. This month: pre-screen the pond. Confirm ownership, surface area, depth and shoreline access, and whether the water body is likely jurisdictional. We run this jurisdictional pre-screen free.
2. Next 30 to 60 days: file for interconnection. For most behind-the-meter projects, the utility is the long pole in the tent. Call your utility's interconnection desk before anything else and ask for their current queue times for your system size.
3. In parallel: size the array and lock pricing. Choose modules and inverters that satisfy the 40% FEOC ratio, and size the float structure to match. Our racking cost guide shows structure-only pricing per kW.
4. Local permits. Building and electrical permit packages go in once the design is fixed. Allow time for plan review and revisions.
5. Procurement. Order modules, inverters and floats with delivery dates that leave slack. Do not schedule anything to arrive in December 2027.
6. Install, inspect, energize. Assemble on the shoreline, float into position, anchor, wire, inspect. "Placed in service" generally means the system is ready and available for its intended use, so get permission to operate well before year end.

The safest plan puts your target in-service date in mid-2027. That leaves six months of buffer for a slow utility, a permit revision or a delayed shipment.

Who should move now

• Farms and irrigation districts with reservoirs that already carry pumping loads, where the array offsets expensive daytime power and shades the water.
• Wastewater and industrial process ponds at facilities with large, steady daytime demand.
• Multi-family, HOA and commercial properties with stormwater retention ponds. See our retention pond guide for sizing.
• Solar EPCs and installers with customers who stalled on ground-mount because of land. A floating array on the customer's own pond may be the fastest project in your pipeline to reach commercial operation before the credit ends.

The bottom line

The credit has not disappeared. For projects that start after July 4, 2026, there is now a hard finish line. Land-based projects that have not started are fighting the calendar. A pond project that starts its interconnection and pre-screen this quarter can finish with room to spare.

This article is general information about federal tax rules as of September 2026 and is not tax or legal advice. Rules and guidance change. Confirm eligibility, beginning-of-construction status and FEOC compliance with a qualified tax professional.

Sources: IRS Notice 2025-42 · Latham & Watkins on Notice 2025-42 · Olson & Partners on the 2027 termination · pv magazine USA on Notice 2026-15 · CRS on the Section 25D expiration