Did the commercial solar tax credit end in 2026?

No. The commercial credit under Section 48E is still 30 percent for projects that begin construction by July 4, 2026. The credit that ended was the residential one, Section 25D, for systems placed in service after 2025. They are separate credits, and the residential change does not affect a business installing solar on its own facility.

What is the difference between the 25D and 48E solar credits?

Section 25D was the residential credit for homeowners, and it ended for systems placed in service after 2025. Section 48E is the commercial and industrial credit for businesses, and it remains at 30 percent for projects that begin construction by July 4, 2026. A commercial owner uses 48E, not 25D.

What is the July 4, 2026 solar deadline?

It is the federal begin-construction deadline to lock in the full 30 percent commercial ITC under Section 48E. A project that begins construction by then preserves the 30 percent credit vintage and has a multi-year window to be placed in service. It is a begin-construction deadline, not a deadline to finish or energize the system.

What happens to the credit after July 4, 2026?

The credit does not disappear; it changes shape against the project. Projects that have not begun construction face a phased ITC step-down and tighter foreign-entity sourcing rules. On a representative 500 kW Illinois project, total post-tax cost rises roughly 25 to 40 percent versus a project that begins construction in time.

Is the 30 percent credit the same everywhere, or can it be higher?

The base credit is 30 percent. A 10 percent Energy Community bonus is added where the facility address sits in an IRS-designated Energy Community census tract, for up to 40 percent federal. Many Illinois industrial corridors qualify, and eligibility is verified at the address using the federal designated-area tool.

Close-up of commercial solar panels with an Illinois industrial facility beyond, representing answers to common questions about the 2026 solar ITC and Illinois incentives

Incentives FAQ

Commercial Solar ITC and Illinois Incentives FAQ: 2026 Answers for C&I Buyers

Direct answers to the questions Illinois commercial and industrial buyers are asking in 2026: the federal solar ITC, the July 4 begin-construction deadline, what the credit is worth, and the Illinois incentives that apply on top.

Published June 3, 2026

9 min read

By Drew Mays

This page answers the questions Illinois commercial and industrial buyers ask most often about solar in 2026: whether the federal credit still exists, what the July 4 deadline requires, what the credit is worth, and which Illinois programs apply on top. Each answer is short and direct. For the full walkthrough, start with the 2026 safe-harbor guide, and for program detail see the Incentives & Safe Harbor pillar.

The federal credit and the 2026 deadline

Beginning construction and safe harbor

What the credit is worth: ROI, depreciation, financing

Illinois incentives and program detail

Costs, the grid, and timing

Get Your Facility's Numbers

Send 12 months of utility bills, one per meter, and your facility address. GEC verifies which federal and Illinois programs apply and returns an indicative design with a per-incentive projection, usually within a week. No commitment to move forward.

About the Author

Drew Mays

C&I Solar & Energy Strategy Advisor

C&I solar and energy strategy advisor. $5M+ in USDA REAP grants secured, 12 states served, SEIA policy contributor. Founder of Envision Energy Solutions and Vice President of C&I Energy Solutions at General Energy Corporation, a 40-year engineering-first EPC with more than 900 completed projects.

drewmays.com

Commercial Solar ITC and Illinois Incentives FAQ: 2026 Answers for C&I Buyers

The federal credit and the 2026 deadline

Did the commercial solar tax credit end in 2026?

What is the difference between the 25D and 48E solar credits?

What is the July 4, 2026 solar deadline?

What happens to the credit after July 4, 2026?

Is the 30 percent credit the same everywhere, or can it be higher?

Beginning construction and safe harbor

How does a commercial solar project begin construction?

How much does it cost to begin construction under the 5 percent method?

Does beginning construction commit me to building the project?

Can I begin construction on a leased building?

What the credit is worth: ROI, depreciation, financing

What is the 30 percent credit worth after depreciation?

Can I sell the tax credit if my business cannot use it?

How is commercial solar financed?

Does battery storage qualify for the credit too?

Illinois incentives and program detail

What Illinois incentives apply on top of the federal credit?

How much is the ComEd solar rebate?

What is Illinois Shines?

Is my Illinois facility in an Energy Community for the 40 percent credit?

Costs, the grid, and timing

Why are my Illinois commercial electric bills rising in 2026?

Is it too late to begin construction before the deadline?

What do you need from me to model my project?

Get Your Facility's Numbers