Equity Capital Contribution Agreement ECCA
An Equity Capital Contribution Agreement (ECCA) is the US tax-equity contract under which an investor commits to fund a project company once the plant is built and a defined set of funding conditions is met, in exchange for the project's tax benefits — the investment tax credit and accelerated depreciation.
The sponsor and the tax-equity investor sign it during construction, but the money moves only at or near mechanical completion or commercial operation date, because the benefits the investor is buying attach to a completed, placed-in-service asset. For BESS this is recent territory: standalone storage only earned ITC eligibility in 2023, which is when the ECCA became a standard document in US storage project finance rather than a solar-only artifact.
Reviewed August 2026 by Sergey Syrvachev
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Why funding lands only after the plant exists
The investment tax credit vests when a project is placed in service, and depreciation runs from the same point — the benefits the investor is buying simply do not exist until the asset does. So the ECCA splits commitment from funding.
The investor signs during construction, but its capital contribution is conditioned on a defined list of funding conditions: mechanical completion certified by the EPC contractor and an independent engineer, a cost-segregation report fixing the eligible basis, tax opinions, no default under any financing agreement, and commonly achievement of commercial operation date itself. Until then, construction is carried by construction debt and sponsor equity. Tax equity is takeout capital — it repays the construction lender at the end; it almost never funds the hole in the ground.
The partnership flip, in one paragraph
The ECCA usually sits inside a partnership-flip structure. Sponsor and tax-equity investor own the project company as a partnership; the ECCA governs the investor's contribution into it, and a companion LLC agreement allocates the economics. In the early years, the bulk of tax items — the ITC and accelerated depreciation, typically five-year MACRS for storage — flows to the investor, along with a slice of cash.
Once the investor reaches a negotiated after-tax yield, allocations flip: the sponsor takes the overwhelming share going forward and usually holds an option to buy the investor out at fair market value. The investor's return is dominated by tax benefits, not merchant revenue — which is why it cares more about basis and placed-in-service dates than about the offtake agreement.
If the funding conditions fail, both sides are in trouble at once: the equity does not arrive AND the construction loan loses its takeout. The agreement usually sits inside a partnership-flip structure, where the bulk of early tax items flows to the investor until it reaches a negotiated after-tax yield and allocations flip to the sponsor. The investor’s return is dominated by tax benefits rather than merchant revenue, which is why it cares more about eligible basis and placed-in-service dates than about the offtake agreement. Transferability changed the default: a project company can sell the credit outright for cash to an unrelated corporate buyer — simpler documents and a shallower diligence lift, but it monetises only the credit, not the depreciation.
- Who signs
- Sponsor and tax-equity investor, at the project-company or partnership level (US structure)
- When money moves
- At or near mechanical completion / COD, after funding conditions are met — never during construction
- What the investor buys
- ITC (commonly 30% of eligible basis) plus accelerated depreciation, typically 5-year MACRS
- Since 2023
- Standalone storage is ITC-eligible and credits are transferable (IRA) — outright credit sales now rival the full ECCA
Transferability changed the default
This is all US-specific, and it moved fast. Standalone storage only became ITC-eligible under the 2022 Inflation Reduction Act, effective 2023 — before that, a BESS had to charge from a co-located solar plant to claim the credit, which warped more than one design. The same law made the credits transferable: a project company can now sell its ITC outright for cash to an unrelated corporate buyer, no partnership required.
That transfer sale has become the common alternative to a full tax-equity partnership — simpler documents, a shallower diligence lift, but it monetizes only the credit, not the depreciation. Larger projects often land on hybrids: a tax-equity partnership under an ECCA that then transfers the credits through to a third-party buyer.
The deadline clause — how construction lenders read it
A construction lender underwrites its own repayment against the ECCA — tax-equity proceeds at completion are the takeout. So the funding conditions become the lender's problem too: every condition the investor can invoke to walk away is a scenario in which the construction loan doesn't get repaid on schedule. Expect the lender to mark up the conditions list, resist anything subjective, and push for a hard outside date with clear consequences.
The clause that bites in practice is the deadline: if commercial operation date slips past the investor's funding commitment expiry — an EPC delay, an interconnection hold-up — the sponsor can be left renegotiating its tax equity from a position of zero strength. Bankability of a US BESS project runs through this one document more than most developers expect.
Tax equity funds construction — the ECCA is how the project gets built.
In reality: It almost never does. Construction is carried by construction debt and sponsor equity; the ECCA is a commitment to fund at completion, once the funding conditions are met. What the signed ECCA does during construction is make the construction loan financeable — the lender sizes its takeout against the committed tax-equity contribution. If the conditions fail, both the equity and the loan repayment are in trouble at once.
Equity Capital Contribution Agreement, in context.
The Grid-Scale BESS course covers equity capital contribution agreement — and the rest of the system — from the ground up, the way it actually gets deployed.