Federal Solar Tax Credit (ITC): Eligibility and How to Claim It
The federal Investment Tax Credit (ITC) is the primary federal incentive mechanism governing residential and commercial solar energy system adoption in the United States. This page covers the statutory structure of the ITC, the eligibility criteria established under Internal Revenue Code Section 48 and Section 25D, the step-by-step process for claiming the credit, and the distinctions between residential and commercial applicability. Understanding how the ITC functions is essential context for evaluating solar energy system costs and structuring any solar installation decision.
Definition and scope
The Investment Tax Credit for solar energy is authorized under the Inflation Reduction Act of 2022 (Public Law 117-169), which extended and modified the credit rates previously governed by the Tax Cuts and Jobs Act and earlier amendments to the Internal Revenue Code. The IRS administers the credit through two distinct code sections:
- Section 25D applies to residential property owners who install solar systems on a primary or secondary residence in the United States.
- Section 48 applies to commercial, industrial, and third-party-owned systems, including power purchase agreement (PPA) structures.
The credit rate under the Inflation Reduction Act is 30% of the total eligible system cost for systems placed in service from 2022 through 2032 (IRS Notice 2023-29). The rate is scheduled to step down to 26% in 2033 and 22% in 2034, before expiring for residential installations after 2034 absent further legislative action.
Eligible costs under Section 25D include solar photovoltaic panels, inverters, racking and mounting hardware, wiring, battery storage systems installed simultaneously with or added to an existing solar array, and labor costs for installation, including permit fees. This scope makes the solar installation permits and approvals process directly relevant to maximizing the credit basis.
The ITC is a nonrefundable credit, meaning it reduces federal tax liability dollar-for-dollar but does not generate a refund if the credit exceeds the taxpayer's liability in a given year. Unused residential credit under Section 25D can be carried forward to subsequent tax years.
How it works
The credit calculation follows a straightforward percentage-of-cost structure, but the details of what qualifies as basis require attention to IRS guidance.
Step-by-step claim process:
- Install a qualifying solar energy system. The system must meet the definition of a qualified solar electric property under IRC §25D(d)(2) or a qualified energy property under IRC §48.
- Determine the total eligible cost basis. Sum all qualifying expenditures: equipment, labor, permits, and interconnection costs. Sales tax on qualifying equipment is includible.
- Calculate the credit amount. Multiply the total eligible cost basis by the applicable credit rate (30% for 2022–2032 installations).
- Complete IRS Form 5695 (for residential filers) or IRS Form 3468 (for commercial/business filers). These forms are filed with the federal income tax return for the year the system is placed in service.
- Apply the credit against federal tax liability. Any unused portion carries forward under the residential carryforward rules.
For commercial installations under Section 48, the credit can be transferred or sold to unrelated third parties under provisions introduced by the Inflation Reduction Act — a mechanism that significantly affects how solar financing options are structured for large commercial and industrial projects.
Solar battery storage systems installed in 2023 or later qualify for the 30% ITC independently, even without a co-located solar array, per IRS guidance under the Inflation Reduction Act amendments.
Common scenarios
Scenario 1: Homeowner with owned system
A homeowner who purchases and installs a 10-kilowatt residential solar system at a total qualified cost of $28,000 calculates a credit of $8,400 (30% × $28,000). If the homeowner's federal tax liability for that year is $6,000, the $8,400 credit eliminates the full $6,000 liability. The remaining $2,400 carries forward to the following tax year.
Scenario 2: Leased or PPA system
Homeowners who lease a solar system or enter a power purchase agreement do not qualify for the Section 25D credit. The credit belongs to the system owner — typically the leasing company or PPA provider — under Section 48. This distinction is critical when comparing solar financing options and evaluating lease-versus-purchase structures.
Scenario 3: Commercial installation with transferability
A business installs a 500-kilowatt ground-mount system (see ground mount solar systems) at a qualified cost of $750,000, generating a Section 48 credit of $225,000. If the business lacks sufficient tax appetite to absorb the full credit, the Inflation Reduction Act's transferability provisions allow the credit to be sold to a third party for cash, typically at a discount negotiated between parties.
Scenario 4: Battery storage added to existing system
A homeowner who installed solar panels in 2020 and adds a standalone battery storage system in 2024 claims the 30% ITC on the battery cost alone, based on IRS rules clarifying storage eligibility under the Inflation Reduction Act.
Decision boundaries
Residential vs. commercial classification:
| Factor | Section 25D (Residential) | Section 48 (Commercial) |
|---|---|---|
| Eligible taxpayer | Individual property owner | Business entity or investor |
| System location | Primary or secondary US residence | Business, industrial, or third-party property |
| Transferability | Not transferable | Transferable/sellable (post-IRA) |
| Direct pay | Not available | Available for tax-exempt entities |
| Carryforward | Yes | Yes, with additional rules |
Placement-in-service requirement: The credit is claimed in the tax year the system is placed in service — defined as the point at which the system is installed, inspected, and operational. Municipalities and utilities govern final inspection and solar interconnection process approval, which technically establishes the placed-in-service date for grid-tied systems.
Prevailing wage and apprenticeship adders: Under the Inflation Reduction Act, commercial systems exceeding 1 megawatt in capacity qualify for the full 30% credit only if the contractor meets prevailing wage and registered apprenticeship requirements established by the Department of Labor (DOL Wage and Hour Division). Systems under 1 megawatt receive the full 30% without these conditions.
State incentive interaction: The federal ITC does not directly reduce the basis for state tax credits in most jurisdictions, but some states require the ITC credit amount to be subtracted before calculating state incentives. Specific interaction rules vary by state and are addressed in the state solar incentives by state resource.
The credit does not affect depreciation basis on commercial systems — businesses claiming both the ITC and Modified Accelerated Cost Recovery System (MACRS) depreciation must reduce the depreciable basis by 50% of the ITC amount, per IRC §50(c), not the full credit amount.
References
- Internal Revenue Code §25D — Residential Energy Efficient Property
- Internal Revenue Code §48 — Energy Credit
- IRS Form 5695 — Residential Energy Credits
- IRS Form 3468 — Investment Credit
- Inflation Reduction Act of 2022, Public Law 117-169
- IRS Notice 2023-29 — Energy Communities
- U.S. Department of Energy — Office of Energy Efficiency and Renewable Energy: ITC Overview
- U.S. Department of Labor, Wage and Hour Division — Prevailing Wage Requirements
- IRS Publication 946 — How to Depreciate Property (MACRS)