The power purchase agreement is usually a renewable project's most valuable single document: it converts an engineering asset into a contracted cash flow, and its terms drive valuation and financeability more than any turbine or module choice.
PPA diligence therefore goes beyond reading the agreement: reviewers reconstruct the full commercial picture from the PPA plus its satellite documents.
The core terms reviewers price
- Term length and start mechanics, including commercial operation deadlines
- Price, escalators, and settlement point (busbar versus hub)
- Volume commitment structure: as-generated, fixed shape, or units
- Curtailment rights and who bears economic curtailment
- Termination events and damages calculations
- Change-of-control and assignment provisions for the financing
Credit support, both directions
Lenders diligence the offtaker's credit as carefully as the project's: the rating or financials behind the buyer, any parent guarantees, and what happens to the contract in an offtaker downgrade. Corporate PPAs with unrated buyers live and die on the guarantee package.
Symmetrically, the project posts its own security, development security before operation and performance security after, and diligence confirms the amounts, form, and step-downs match what the model assumes.
The satellite documents
- Guarantees and letters of credit supporting both parties
- Consent to collateral assignment for the lenders
- Estoppel certificates confirming no defaults exist
- Amendments and side letters, all of them
- REC transfer and registry documentation where bundled
- Scheduling and settlement history, for operating assets
Common red flags
The recurring diligence findings: commercial operation deadlines the construction schedule cannot meet, uncapped or vaguely drafted curtailment provisions, missing consents to assignment that stall financing, and side letters that quietly amend headline terms without appearing in the main folder.
The process point behind all four: every amendment and side letter belongs in the room next to the PPA, because the agreement reviewers price is the agreement as amended, not as signed.
Next steps
FAQ
What makes a PPA bankable?
A creditworthy offtaker or guarantee package, adequate term length, workable curtailment allocation, assignment consent for lenders, and deadlines the project can realistically meet.
What is basis risk in a PPA?
The price difference between where the project delivers power (its node) and where the PPA settles (a hub): the project keeps that spread, favorable or not, unless the contract says otherwise.
What is a consent to assignment?
The offtaker's agreement that the PPA can be collaterally assigned to lenders, with cure rights if the project defaults. Financings routinely wait on this document.