Tax equity is one of the most important—and most misunderstood—components of the U.S. solar capital stack. For developers, investors, and advisors financing solar infrastructure, understanding how tax equity works is essential to structuring bankable projects and maximizing returns.
What is tax equity?
Solar projects generate valuable federal tax benefits, primarily the Investment Tax Credit (ITC) and accelerated depreciation (MACRS). Many project developers cannot fully use these benefits themselves because they lack sufficient tax liability.
Tax equity investors—typically large financial institutions with substantial tax appetite—provide capital in exchange for the right to monetize these benefits. This partnership allows the value of the incentives to flow to a party that can actually use them.
Common structures
Several structures allocate tax benefits and cash flows between parties:
- Partnership flip: the tax equity investor takes most benefits until reaching a target return, then the allocation "flips" to the sponsor
- Sale-leaseback: the sponsor sells the project and leases it back
- Inverted lease: used in specific circumstances to pass the ITC to a lessee
Each carries different accounting, risk, and return implications. The right structure depends on offtake terms, sponsor profile, and lender requirements—making bankable PPA design a prerequisite for competitive tax-equity terms.
Transferability and hybrid structures
Since 2023, developers have also been able to sell federal credits directly to unrelated corporate buyers under Section 6418. The transfer market has scaled quickly—roughly $42 billion in credits changed hands in 2025, and total tax credit monetization across tax equity, hybrids, and transfers reached about $63 billion.
The fastest-growing approach is the hybrid: a traditional partnership captures depreciation and any basis step-up, while the credit itself is transferred to a third-party buyer. These "T-flip" structures now account for the majority of tax-equity commitments, combining partnership economics with a much broader buyer pool.
The OBBBA changes the calculus
With the phase-out of the solar ITC under the One Big Beautiful Bill Act, credit-eligible projects—those with defensible beginning-of-construction positions or a clear path to a 2027 in-service date—carry embedded value that the shrinking eligible pipeline makes scarcer. Diligence on construction-start documentation and safe-harbor equipment spend is now a core part of every tax-equity and transfer negotiation.
Why it matters for returns
Tax equity typically funds a meaningful share of a project's capital cost, reducing the amount of sponsor and cash equity required. Efficient tax-equity structuring can materially improve project-level and investor returns.
The role of disciplined structuring
Tax equity investors conduct rigorous diligence. Bankable production estimates, creditworthy offtake, and sound legal structures—validated through institutional underwriting—are prerequisites for attracting competitive terms.
How Sunlight helps
Sunlight Energy Investments structures capital stacks, including project equity, tax equity, and debt, tailored around each project's economics. We position projects to attract the right capital partners and reach financial close.
To discuss project finance, explore our advisory services or contact us.