A solar power purchase agreement (PPA) is a contract to buy electricity produced by a solar project under agreed pricing and delivery terms. In a common on-site arrangement, a third party owns and operates the system on the host’s property, and the host purchases its output. The host buys electricity rather than purchasing the solar equipment outright.
This page focuses on that on-site model. Off-site physical and financial arrangements can allocate delivery, market and settlement risks differently.
How an on-site PPA works
The parties agree where the system will be located, who owns it, how electricity is measured and what the buyer pays. Site access, maintenance, insurance, contract length and end-of-term arrangements also need definition.
The EPA’s solar PPA explanation describes the third-party ownership model. Its general discussion is not a current offer, tax determination or guarantee that a particular customer will save money.
| Question | Why it matters |
|---|---|
| Who owns the equipment? | Determines asset responsibilities and rights |
| What electricity must be purchased? | Establishes payment obligations and treatment of output |
| How does the price change? | Affects the long-term comparison with other options |
| Who maintains the system? | Defines operational responsibility and access |
| Who owns environmental attributes? | Determines which renewable-energy claims may be supported |
| What happens when the term ends? | Establishes purchase, renewal or removal options |
Compare a PPA with ownership and leasing
With ownership, the customer acquires the system and carries the responsibilities allocated by its installation, financing and maintenance arrangements. A lease generally charges for use of equipment under the lease terms. A PPA charges according to the agreed electricity-purchase structure.
Those distinctions do not resolve every commercial detail. Contracts can contain minimum obligations, access provisions, buyout formulas and other terms that materially change the comparison. Review the actual documents rather than assuming the label describes every risk.
The EPA customer PPA resource also distinguishes energy purchases from renewable energy certificates. Electricity and its environmental attributes should not be treated as automatically inseparable.
Evaluate the complete bill effect
A PPA price below one electricity rate on a utility bill does not prove a lower total bill. The analysis needs the charges solar actually offsets, the timing of generation, remaining utility charges, export treatment and any price escalation.
An illustrative property uses little electricity on weekends. Its on-site array can still generate then, but the financial treatment depends on the contract and utility arrangement. The owner must understand whether it purchases all production, how exports are valued and whether those assumptions are included in the model.
Use current project-specific data. This glossary does not assume that historical tax credits or incentive programs remain available, or that their value automatically belongs to the host.
Property changes deserve attention before signing
A long-term energy agreement can outlast a tenant’s lease or a roof’s remaining useful life. Address property sale, lease expiry, reroofing, equipment relocation and early termination before those events become urgent.
Clarify who pays for temporary removal and reinstallation if building work is required. The system owner’s maintenance duty does not necessarily include work triggered by the host’s unrelated renovation.
For procurement teams, the agreement should also identify performance reporting, dispute processes and the evidence used to calculate invoices. Metering arrangements need to be understandable to both parties.
A useful proposal comparison
Request consistent assumptions for generation, purchase obligations, escalation, utility charges, property work and end-of-term treatment. Ask for sensitivity analysis rather than a single favorable savings curve.
Legal, tax and financial reviewers should evaluate the terms within their respective scopes. A technically suitable solar site does not establish that every financing arrangement is suitable for its owner.
Separate the project roles before reviewing the price
The host, electricity buyer, system owner, developer, installer and maintenance provider may be different parties. A proposal should identify who performs each role and which obligations remain with the property owner. The organization presenting the offer may not perform every part of the project itself.
The EPA’s on-site PPA explanation describes this third-party ownership structure. Its historical examples of rates, timing and incentives should not be treated as current terms available to a particular customer. The actual proposal and applicable requirements determine the arrangement.
For an illustrative leased property, the tenant may buy electricity while the landlord controls the roof. The agreement needs a workable relationship among those interests. A technically suitable solar layout does not resolve the required property rights or the consequences of a tenant leaving.
Map the roles in plain language before comparing the financial model. That makes it easier to identify who handles construction, operating issues, access requests, invoices and later property changes.
Define the electricity being purchased
The agreement should explain how production is measured and which quantity creates a payment obligation. The measurement point, billing period and treatment of unusual conditions affect how an invoice is interpreted. The buyer should be able to connect the reported energy to the contract’s defined purchase.
An illustrative host may assume it pays only for energy used immediately inside the building, while a proposed agreement may describe a different obligation associated with system production. That difference needs resolution before the owner relies on a savings model.
Ask how exports, curtailment and periods of unavailable equipment are treated under the actual agreement. These are contract questions, not terms that can be inferred universally from the acronym PPA. The analysis should use the same treatment as the document being evaluated.
Also identify the process for reviewing meter data or disputing an invoice. A long-term arrangement is easier to administer when both parties understand the evidence supporting payment and the route for resolving a discrepancy.
A price escalator changes the comparison over time
Some agreements use a fixed electricity price, while others include an adjustment mechanism. The actual terms determine how the price changes. A low starting price should therefore be evaluated together with the full price path and any conditions affecting it.
For an illustrative comparison, one offer may begin lower but increase under a stated formula, while another holds a different fixed price. The buyer needs a consistent model over the relevant evaluation period to compare them. Looking only at the first year’s price can obscure the later relationship.
Utility-price assumptions deserve equal scrutiny. A proposal should not present future utility costs as certain merely because a spreadsheet uses a smooth escalation curve. Identify the source and nature of the assumptions, then examine how the result changes under other plausible scenarios.
The objective is not to predict every future bill perfectly. It is to understand which commercial assumptions support the proposed benefit and how much the decision depends on them.
Compare the remaining utility bill as well as the PPA payment
An on-site solar agreement does not necessarily eliminate the site’s utility relationship. The building may still purchase electricity when solar production is insufficient, and some charges may remain despite reduced energy purchases. The applicable tariff and operating pattern determine the actual effect.
An illustrative business that operates late into the evening may continue buying substantial electricity outside solar-producing hours. Another property may export energy during low-use periods. A useful model reflects those patterns rather than assuming every generated unit offsets the same utility charge.
Show the PPA payment and the remaining utility costs separately before combining them. This makes the comparison understandable and helps reviewers identify double counting or omitted charges. The baseline should describe what the site would otherwise pay for the same service.
If storage or other equipment is included, identify its separate cost and operating assumptions. The PPA label alone does not establish that every additional technology or service is part of the offered arrangement.
Renewable-energy claims depend on environmental attributes
Electricity purchases and renewable-energy certificates or other environmental attributes are related but distinct contractual matters. The agreement should identify who owns the relevant attributes and whether they are transferred or retired for the buyer’s intended claim.
The EPA customer PPA resource discusses the allocation of renewable-energy attributes. A host should not assume that having panels on its property automatically supports every statement it wants to make about renewable electricity use.
For an illustrative institution preparing a sustainability report, the procurement team should coordinate with the people responsible for reporting. They need to know what evidence the agreement provides and whether the planned claim matches the attribute treatment.
Keep this issue separate from physical production. The system can generate electricity while the contractual rights relevant to a particular environmental claim belong elsewhere. Review the actual terms and applicable reporting framework rather than relying on the appearance of the installation.
Building work can interrupt the solar arrangement
A PPA can extend beyond a tenant’s current plans or a roof’s remaining suitability. The parties should address foreseeable property events, including reroofing, equipment changes, renovations, sale and lease transitions. These issues are easier to evaluate before construction than during an urgent building repair.
An illustrative host may need roof work that requires temporary removal of part of the array. The agreement should explain the relevant responsibilities, approvals and commercial consequences. The system owner’s ordinary maintenance obligation should not be assumed to cover every cost caused by unrelated property work.
Access rights also need practical treatment. The owner should understand when the system provider can enter, what coordination is required and how access interacts with security or occupied-building operations. The arrangement must work for the property as well as for the equipment.
Bring known building plans to the technical and commercial review. A financing structure should not be selected independently of conditions that could affect the installation during its term.
Performance responsibility needs a defined scope
Third-party ownership can allocate important operating responsibilities away from the host, but the actual contract determines what that means. Ask who monitors production, responds to faults, maintains the equipment and reports performance. Identify any conditions, exclusions or owner duties that affect those obligations.
A production estimate, a contractual performance commitment and a payment calculation are different items. The proposal should distinguish them. An expected generation curve is not automatically a guarantee, and a guarantee should have a defined measurement method and consequence.
For an illustrative facility with a monitoring concern, the host should know whom to contact and what information it can access. A service arrangement that is unclear about reporting or response can be difficult to manage even when the ownership model appears simple.
The project should also identify construction and acceptance responsibilities. Owning the system and installing it may involve different entities, so the handover needs a clear route for resolving defects and transferring operating information.
End-of-term and early-exit provisions deserve early attention
An agreement may provide options involving continued service, purchase or removal at the end of its term. The actual conditions, timing and valuation method matter. Do not assume that the equipment automatically becomes the host’s property without cost or further obligations.
Early termination can raise different questions from ordinary end-of-term treatment. A property sale, tenant change or business decision may interact with assignment, consent or payment provisions. Those terms need qualified contract and financial review for the buyer’s circumstances.
Ask what the owner must do, by when, and what happens if it does not exercise an option. A useful comparison records those decision points alongside the price rather than treating them as minor details to revisit many years later.
The practical outcome of a PPA review is an understood long-term purchase arrangement. The owner should know what electricity it buys, how the price changes, which responsibilities it retains and what happens when the property or agreement changes. Technical feasibility informs that review, but it does not replace it.
Common questions
Is a PPA free solar?
No. It is a contractual purchase arrangement. Upfront equipment ownership may be avoided in a particular offer, but electricity payments and other obligations still apply.
Does the host receive all solar incentives?
Do not assume so. Eligibility, ownership and contractual allocation matter, and current program rules require separate verification.
Can a PPA work on a leased property?
Potentially, but property rights, landlord approval and the relationship between the lease and PPA terms must be resolved.
Does Soleil offer or finance PPAs?
Soleil’s published solar capabilities do not establish a particular PPA financing product. Discuss project delivery separately from the financing provider and contract terms.
Establish the project before choosing the agreement
Soleil Energy’s renewable energy team can discuss the site’s solar scope and delivery requirements. Bring the property arrangement and electricity-use information so technical feasibility can inform the commercial evaluation.
Project requirements depend on the site, equipment and applicable rules. Confirm design and installation decisions with the appropriate qualified professional.
