Negotiating Power Purchase Agreements (PPA): the key clauses for producers and customers

Types of PPAs and supply structures

On-site or direct-wire PPA. In this model, electricity is supplied directly from the generator to the consumer via a private line. It is particularly suitable where generation and consumption are geographically linked and the line and metering structures can be clearly defined from a technical perspective.

Physical PPA via the public grid. In this case, supply takes place via the grid. Consequently, grid usage, the balancing group, schedule management and balancing energy must be incorporated into the contractual structure. This model is frequently chosen to supply a company site with electricity from a specific generation plant on a long-term basis.

Sleeved PPA. In a sleeved arrangement, an energy supplier or specialised service provider assumes the operational market roles, in particular balancing group management, dispatch planning, balancing energy and billing. This structure is suitable when the generator and the consumer agree on the physical supply but do not wish to handle the energy-related processing themselves.

Virtual or synthetic PPA. This model is structured as a financial difference settlement against a reference price. The electricity generated is sold separately on the market, whilst the consumer meets their physical demand independently of this. A virtual PPA can therefore also be used to hedge prices in the long term across sites or market areas.

In addition, it must be specified whether payment is due on a ‘pay-as-produced’ basis, as a fixed volume supply, or according to a structured profile. This choice determines who bears the weather, profile and balancing energy risks. In the case of a corporate PPA, it is also necessary to examine how guarantees of origin are transferred and redeemed. Only when electricity supply, guarantees of origin and sustainability reporting align can the customer reliably use the renewable origin in their reporting.

Price, term and operational risks

The price may be fixed, indexed or structured as a combination with a floor, cap or collar. In the case of indexed models, the reference market, price band, calculation period, negative prices and data source must be clearly defined. Inflation or cost indices also require a fallback provision in the event that the index is discontinued or its methodology is significantly altered.

Production risk relates to the consequences of a sustained reduction in plant output. This must be distinguished from profile risk: even if the annual volume is achieved, generation and consumption may not coincide in time. The contract must therefore specify who is responsible for producing forecasts, submitting schedules and bearing the costs arising from balancing group imbalances or balancing energy.

Grid-related interventions constitute a further risk category. For curtailment and redispatch, it must be specified whether the affected volume is deemed to have been supplied, how compensation is to be handled, and what evidence the generator must provide. Planned maintenance windows, minimum technical availability and ongoing reporting obligations should also be described in such a way that outages can be clearly attributed.

Finally, the contract requires rules governing excess production. It must clarify whether the off-taker is obliged to take on additional volumes, is granted a right of choice, or whether the generator is permitted to sell the surplus freely on the market. Only the interplay of these provisions accurately reflects the project’s actual volume and profile risk.

For new projects, development, construction and commissioning risks must be addressed separately. The long-stop date, permits, grid connection, damages for delay and any right of withdrawal must be consistent with the project financing. The off-taker’s creditworthiness is just as important to the generator as the technical quality of the plant. Common security instruments include group or bank guarantees, letters of credit, escrow accounts, margining or a right to request additional collateral in the event of a rating downgrade. The collateral should cover not only current receivables but also any potential termination damages.

Change in Law, Force Majeure and Termination of Contract

A change-in-law clause should not automatically trigger a repricing for every legal change. It must define which changes are covered, which cost or revenue effects are material, and whether this is followed first by adjustment negotiations, an expert assessment procedure or a right of termination. Particular attention should be paid to taxes and duties, grid tariffs, accounting rules, guarantees of origin and requirements for the marketing of renewable energy.

Force majeure refers to events beyond the reasonable control of a party. Not every technical fault or price fluctuation constitutes force majeure. The contract should set out notification, mitigation and resumption obligations, as well as a maximum duration after which a party may terminate the contract.

In the event of early termination, the settlement formula determines the financial outcome. The following points must be clarified: grounds for termination and cure periods; insolvency or deterioration in creditworthiness; close-out or replacement value; outstanding guarantees of origin and collateral; and the continued applicability of confidentiality and dispute resolution provisions.

For long-term contracts, a tiered dispute resolution mechanism is recommended: operational escalation, management discussions, and, where necessary, an expert to address pricing or volume issues, followed only then by court proceedings or arbitration.

Bankability and the execution of the PPA

When assessing financed generation projects, banks examine not only the price and term but also the overall robustness of the contract. Key factors include a creditworthy off-taker, a sufficient contract term, clear availability and termination provisions, and a security package that also covers damages in the event of early termination. Financiers frequently require rights to information, grace periods and a right of step-in before the off-taker is permitted to terminate the contract due to a breach of obligation by the generator. These requirements should be incorporated early in the contract drafting process; amending a PPA that has already been negotiated is often difficult.

In new projects, there is also often a gap between the signing of the contract and the start of supply. Between these two points, approvals, financing, grid connection and commissioning must be finalised. The contract should therefore distinguish between the conditions that must be met for it to take effect, the conditions that trigger the Commercial Operation Date, and the consequences of any delay. A robust long-stop mechanism links the grace period, compensation for damages and the right of termination to the question of whether, and to what extent, development or hedging costs already incurred will be reimbursed.

Finally, the PPA must be consistent with the other project contracts. The plant construction contract, operations management, grid connection, direct marketing, financing and security arrangements must not contain any conflicting deadlines or liability regimes. Of particular importance is the alignment of availability obligations with the plant constructor’s performance commitments, and the treatment of balancing energy in relation to the contract with the balancing group manager.