Corporate PPAs for Illinois Load with PJM-Region Projects

A corporate power purchase agreement (PPA) is one of the more powerful, and more complex, tools a large energy buyer can use. For Illinois businesses in ComEd territory, whose grid sits inside the PJM Interconnection, PPAs tied to PJM-region projects are a natural fit for pursuing renewable goals at scale. But a PPA is a multi-year commitment with genuine financial risk, and it is unlike anything on a standard supply contract. This guide explains what a PPA is, the two main structures, how they relate to your load and to PJM, and what to weigh before signing.

What a PPA is

At its core, a PPA is a long-term contract for a specific project's output and its environmental attributes, usually the renewable energy certificates (RECs) the project produces. Instead of buying a matched renewable product from a supplier month to month, you are committing to a particular wind or solar project over a long horizon, often to help make that project financeable. That is the additionality argument for PPAs: your commitment can support new renewable build in a way a spot REC purchase may not.

Because a PPA is long-dated and tied to one project, it behaves partly like a hedge. You are effectively fixing a price relationship for a slice of generation over many years, which cuts both ways depending on where markets go.

Physical vs. virtual (financial) PPAs

The single most important distinction is whether power physically moves.

Physical PPA. Energy from the project is actually delivered and scheduled to serve load. This requires the project to be positioned so its output can be delivered into the market serving you, and it involves the operational machinery of scheduling and settling real energy. Physical PPAs are typically pursued by buyers with the sophistication, or partners, to manage delivery and balancing.

Virtual (financial) PPA. No electricity is delivered to your meter. Instead, you and the project agree on a contract price, and you settle the difference between that price and a reference market price for the project's output. If the market price is above the contract price, the settlement flows one way; if below, it flows the other. Separately, you receive the project's RECs to back your renewable claim. A virtual PPA is therefore a financial contract plus an attribute purchase that sits alongside your ordinary supply arrangement; it does not replace how you actually buy the electricity you consume.

For many Illinois corporate buyers, the virtual structure is the more accessible one, because it delivers the renewable claim and a price hedge without requiring you to take physical delivery or manage scheduling.

How PJM projects relate to your Illinois load

ComEd's northern Illinois grid operates within PJM, the regional transmission organization that runs the wholesale markets for its footprint. (Ameren Illinois, in central and southern Illinois, sits in MISO instead, a distinction that matters for where a project settles and how basis behaves.) A PPA tied to a PJM-region project references PJM market prices for settlement, which is why buyers with PJM-zone load often look to PJM projects: it keeps the contract's reference market aligned with the region their operations sit in.

That alignment is never perfect, though. The price where a project delivers into the grid and the price relevant to your load are set at different locations, and the gap between them, basis, moves independently. Basis risk is one of the defining features of a virtual PPA and is discussed further in our guide on grid congestion and basis risk in the PJM/ComEd zone.

The key risks to weigh

A PPA is not a set-and-forget product. Before committing, model and understand:

• Price/settlement risk. With a virtual PPA, if the market price settles below your contract price, the settlement can run against you. You must be comfortable with a range of outcomes over the full term, not just the favorable case.
• Basis and congestion risk. The difference between the project's delivery point and your load reference can erode or amplify the intended hedge. Understand how it is defined in the contract.
• Shape and production risk. Renewable output is variable. How production shape lines up (or does not) with your consumption affects the real value you get.
• Term and credit. These are long contracts. Consider your own credit obligations, the counterparty's, and what happens on default, assignment, or early exit. Our contract review principles apply, with more at stake.
• Accounting and claims. Confirm you are receiving and retiring the RECs cleanly, without double-counting, so your renewable claim holds up. See green claims compliance.
• Interaction with your supply. A PPA does not remove the need to actually buy the power you use. Make sure your PPA and your underlying supply strategy are designed together.

Who a PPA is, and isn't, for

PPAs generally suit larger buyers with meaningful load, a long planning horizon, the credit standing to enter a multi-year commitment, and the analytical capacity, in-house or advisory, to model the risks above. For smaller buyers or those wanting simplicity, a green supply product, unbundled RECs, or community solar will usually be a better match.

Approached with clear eyes, a PPA can support new renewable development, provide a long-term price hedge, and deliver a strong additionality story. It can also settle against you in a given period if markets move the wrong way. It is a risk-management and sustainability decision, not a guaranteed saving; model the downside, confirm how settlement and basis are defined, and align it with your overall supply plan before signing.

Sources

• PJM Interconnection
• Midcontinent Independent System Operator (MISO)
• Illinois Commerce Commission
• Illinois Power Agency

This guide is educational and does not promise savings; a PPA carries real price and settlement risk, and you should model outcomes and confirm current market and program specifics with primary sources before acting.