PPA Credit Support: Who Posts, When, and What the Security Actually Protects

Credit support is not inherently one-way. A project company may post development or performance security to its offtaker; a buyer may be required to post a letter of credit, cash collateral or a guaranty; and some PPAs use rating thresholds so security changes over time.

The useful question is not “who normally posts?” It is “which exposure is secured at this stage, in what form, and what happens when the credit assumption changes?” Public PPAs show both seller-side and buyer-side security structures, which is why a financing model should never hard-code zero buyer security or assume seller security disappears at COD.

This is the first of three PPA Standalones that close out Contracts & Legal. You will get how seller and buyer security can differ, how downgrade and replacement mechanics work, what an LC consumes inside the financing, and how to distinguish short-term receivable exposure from the much larger value of the remaining offtake contract.

ℹ️ Note: This describes how these mechanisms work in practice. It is not legal or investment advice — security packages are heavily negotiated and vary by offtaker type and market.

Who Posts Security to Whom?

Whichever party the PPA requires.

Two public examples make the point.

• A Nevada geothermal PPA required the supplier / seller to provide development security in the form of an LC or cash deposit, with the amount tied to the annual supply quantity.
• The Fire Island Wind PPA defined Buyer Security as a buyer-posted LC, cash held by a custodian, or a guaranty, each sized to the Required Security Amount.

Those structures are not contradictory. They secure different credit exposures at different stages.

For diligence, build a two-sided table:

Party	Exposure being secured	Amount	Form	Trigger	Release / replacement
Seller	development / COD / performance obligations	$	LC / cash / guaranty	execution / milestone	COD / replacement security
Buyer	payment / termination exposure	$	LC / cash / guaranty	rating / credit threshold / execution	rating recovery / expiry

The model then prices the actual instrument rather than a market convention.

How Is the Seller's Security Sized?

From the actual PPA formula.

Some agreements use a fixed development-security amount. Others link security to delay exposure, installed capacity, expected payments or another contractual measure. Post-COD security can use a different formula entirely.

Build the schedule directly from the contract:

Development security
Step-up / step-down dates
COD security
Operating security
Downgrade trigger
Release conditions
LC expiry / renewal

When Does the Buyer Need to Post?

That is a counterparty-credit question.

If the buyer or its guarantor satisfies the PPA's credit standard, no collateral may be required. If the buyer is unrated, sits in a thin SPV, or falls below a negotiated threshold, a posting obligation can arise.

Model the trigger and cure process rather than assuming buyer security is always zero.

What Does a Letter of Credit Actually Consume?

Liquidity and bank commitment.

A project LC is not just a piece of paper delivered at closing. The account party needs an issuing facility, pays fees, may need collateral or reimbursement support, and has to maintain the instrument through expiry, renewal and any replenishment requirement.

Recent SEC-filed project-finance agreements show how material the commitments can be. One 2026 financing provides for PPA letters of credit up to $52.265 million. Another project financing provides PPA LC commitments of $22.25 million before term conversion and $25.25 million afterward.

Those figures are not benchmarks for another project; they demonstrate that PPA credit support can be a material financing facility in its own right.

The model should therefore track:

LC face amount
commitment fee / fronting fee
cash collateral requirement, if any
expiry and auto-renewal
issuer rating requirements
replacement trigger
replenishment after draw
whether the LC survives term conversion

A parent guaranty consumes a different resource: sponsor credit capacity rather than bank LC capacity. Cash collateral consumes project liquidity directly. The cheapest instrument on its face is not always the cheapest instrument for the capital structure.

When Does the Seller Get Its Security Back?

On milestones, and the release schedule is worth as much attention as the amount. Security that is posted early and released late is a longer, more expensive obligation than the headline figure suggests, and the difference is pure carrying cost.

The natural break is commercial operation. Development security exists to cover the offtaker's schedule exposure, and that exposure ends when the plant delivers — so the instrument should be released at COD and replaced by the post-COD performance security. Two failure modes recur.

Overlap. If development security is not released until the post-COD instrument is in place and accepted, the project briefly carries both. On the numbers below that is roughly $12.8m of simultaneous posting, against a special purpose entity with no spare liquidity. The overlap is usually administrative rather than intended, and it is fixable by drafting the release as automatic on the same event that triggers the replacement.

Drawn-down security is not restored security. If the offtaker draws on development security for delay damages, the instrument is reduced. Most PPAs require the seller to replenish it to the full amount within a short period. That obligation arrives during a delay — when the project is already absorbing carrying cost and has already established that it is behind schedule. The replenishment covenant is a liquidity call at the worst possible moment, and it belongs in the downside case rather than in the legal summary.

Operating-period step-ups or step-downs are entirely contract-specific. Build the actual schedule from the PPA and financing documents, because the maximum posting requirement may occur at execution, COD, a downgrade, a later milestone or after a draw and replenishment.

Why Do Lenders Care About Collateral Assignment?

Because the PPA is the security. The debt is sized against contracted revenue, so the contract producing that revenue is the most valuable asset the lenders take — more valuable, in a distressed case, than the hardware.

PPAs therefore contain provisions permitting the seller to assign the agreement as collateral, together with protections for the lenders taking it. Those protections matter more than the assignment itself, and they run in two directions.

Cure rights before termination. As post 3 covered, Without it, an offtaker could terminate for a curable seller default and extinguish the lenders' principal security before they had an opportunity to act.

Notice and standstill. The direct agreement normally requires the offtaker to notify the lenders of a seller default and to hold off on termination for a defined period. That standstill is what converts a theoretical cure right into a usable one — a cure right without notice is a right to fix something you were never told about.

The practical consequence for the security package is that the seller's posted instruments and the lenders' direct agreement protect different things. The LC covers the offtaker's monetary exposure to delay or non-delivery. The direct agreement covers the lenders' exposure to losing the contract entirely. A project can have ample posted security and no meaningful lender protection, or the reverse, and the two are negotiated by different parties at different times.

One diligence check is worth doing early: confirm the offtaker has actually agreed to the direct agreement terms the lenders will require, before the PPA is signed rather than after. Retrofitting consent from a counterparty that has already secured the commercial terms it wanted is materially harder.

How Do You Price the Exposure That Remains Unsecured?

Separate near-term receivables from loss of the contract itself.

For receivables, the standard credit decomposition is useful:

Expected loss = probability of default × exposure at default × loss given default

Exposure at default on ordinary invoices is driven by settlement frequency, payment lag and any posted collateral. That is usually much smaller than the economic value of the remaining PPA.

The larger exposure is replacement of the offtake after a default or termination. That value depends on the remaining term, market replacement price, termination-payment formula, recovery against guarantees or collateral, and the time required to re-contract.

Keep those two exposures separate:

Receivable EAD
Termination / replacement-value exposure
Posted buyer security
Parent-guarantee support
Recovery assumption

Moving from monthly to more frequent settlement can reduce receivable EAD without changing the loss of the long-term contract. Likewise, a modest LC can fully cover invoices and still be far smaller than the termination exposure.

How Do You Model Credit Support in Excel?

Three blocks: what you must post, what you are owed and cannot collect, and what the gap is worth.

The inputs

Assumptions, labelled as such:

Contract capacity                     150 MW
PPA price                             $45.00 /MWh
P50 annual energy                     250,000 MWh
Annual PPA revenue                    $11,250,000
PPA delay damages                     $12,000 /day
Target COD                            2027-06-01
Drop dead date                        2028-06-01
Post-COD security requirement         9 months of expected payments
LC annual fee                         1.40%
Offtaker one-year PD                  0.60%
Loss given default                    65%

Block one — what the seller posts

Development_Security = PPA_Delay_Damages_Per_Day × (Drop_Dead − Target_COD)
                     = 12,000 × 366                            = $4,392,000

Post_COD_Security    = Annual_Revenue × (9 / 12)               = $8,437,500

LC_Annual_Cost       = 8,437,500 × 1.40%                       = $118,125

Note what the first line is doing. Widening the longstop by 90 days adds 90 × 12,000 = $1.08m to the posting obligation. The schedule flexibility negotiated in the PPA has a direct liquidity price, and it is rarely quoted alongside the drafting concession that creates it.

Block two — what the buyer does not post

Buyer_Security_Posted = $0    (investment-grade offtaker, no posting until downgrade)

Receivable_Exposure   = Annual_Revenue × (Settlement_Days / 365)
                      = 11,250,000 × (45 / 365)                = $1,386,986

Contract_Exposure     = NPV of remaining PPA margin over term

The receivable is the small, visible number. The contract exposure — the value of losing a twenty-year offtake and replacing it at merchant or at whatever the market offers a distressed seller — is the large invisible one, and it is the reason a rating downgrade is a financing event rather than an administrative one.

Block three — the expected loss

Annual_EL = PD × Exposure_At_Default × LGD
          = 0.60% × 1,386,986 × 65%                            = $5,409

Downgrade_Contingent = Buyer posting obligation triggered at sub-IG
                     = 9 months of payments                    = $8,437,500

The annual expected loss on receivables is trivial — which is exactly why nobody collateralises it, and exactly why the number is misleading on its own. The risk is not the receivable. It is the contingent event: a downgrade that either produces $8.4m of buyer-posted security or produces a default and a termination right nobody wants to use.

The comparison worth reporting

Seller_Posts     = 4,392,000 (development) → 8,437,500 (post-COD)
Buyer_Posts      = 0, contingent on downgrade
Seller_Exposure  = ~20 years of contracted margin
Buyer_Exposure   = ~2 years of construction schedule

Four lines. The party posting security is the party with the shorter exposure, and the party with the longer exposure posts nothing. That is not necessarily wrong — it is a considered allocation based on relative credit — but it should be stated rather than assumed, because it is the structure the whole financing rests on.

ℹ️ Note: Model the LC fee as an operating cost across the full period it is held, not as a closing cost. At 1.4% on $8.4m held for fifteen years it is roughly $1.8m of undiscounted cash, which is the kind of item that disappears into "other" in a sources and uses table.

To run the full version — development security sized off your own date ladder, post-COD security stepped through a levelized-price crossover, LC fees carried as a period cost, and the downgrade trigger modelled as a contingent obligation — prompt Dezzmond with your PPA security provisions and price curve.

What Do Lenders Actually Check?

Lenders read the security package twice: once for what the project must fund, and once for what protects the revenue they are lending against.

• What must the project post, and when? Development security and post-COD security are both uses of funds and belong in sources and uses, not in a footnote.
• What form, and what is the draw mechanic? On-demand instruments are treated very differently from guarantees requiring proof of default.
• What is the LC fee over the full holding period? A standing annual charge against the cash flow the debt is sized on.
• Is the offtaker rated, and by whom? An unrated corporate or an unrated subsidiary of a rated parent are different credits from a rated utility.
• What is the downgrade trigger, and what happens if the buyer fails to post? Including whether the resulting termination right is one the project would ever want to exercise.
• How frequent is settlement? It sets exposure at default on receivables directly.
• Does a guarantee reach the full obligation? A guarantee limited to defined obligations may not cover a termination payment.

Frequently Asked Questions

Why does the seller post security when the buyer owes far more money?

Because the credit positions are asymmetric. A utility offtaker typically holds an investment-grade rating and is treated as an acceptable unsecured counterparty, while the seller is a special purpose vehicle with no balance sheet and an asset that does not yet exist.

How is development security sized?

Use the signed PPA formula. If it references delay damages, model the same dates and rate used in the delay schedule; if it is fixed, model the fixed amount and release conditions.

What happens if the offtaker is downgraded?

A negotiated threshold, commonly investment grade, triggers a posting obligation. The difficulty is that the trigger correlates with the counterparty's ability to satisfy it, so the practical outcome is often a renegotiation rather than collateral.

When is cash a poor form of security?

When project liquidity is scarce and an LC or guarantee can provide equivalent contractual protection at lower opportunity cost. The answer is transaction-specific.

Closing: The Instrument Is Not the Exposure

Credit support is the part of a PPA that looks most like a solved problem. There is a defined amount, a defined form, a defined trigger, and a bank standing behind it. Everything is quantified.

What is quantified is the seller's obligation. The project's own largest exposure — two decades of payments from a single counterparty — sits on the other side of the same section, uncollateralised, supported by a rating and a contingent posting obligation that fires when the rating fails. That is a reasonable structure against a regulated utility and a considerably less reasonable one against an unrated corporate, and the drafting frequently looks the same in both cases.

The series pattern holds for the ninth time. The development security is the date ladder from post 3, priced. The LC draw mechanics are the security question from post 2, repeated with a different counterparty. And the exposure that matters is the one with no instrument against it — which is how every post in this material has ended, because that is where the money is.

Next: deemed generation, and how an offtaker pays for power it refused to take.

Related reading: Deemed generation and curtailment · PPA termination value and buyout schedules

Sources: SEC-filed Fire Island Wind PPA — buyer LC / cash / guaranty security · SEC-filed Nevada geothermal PPA — seller development security · 2026 SEC-filed project financing — $52.265m maximum PPA LC commitment · SEC-filed project financing — $22.25m / $25.25m PPA LC commitments · Dezzmond analysis; worked-example assumptions are illustrative.