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Evaluate solar proposals against the same published requirements, site facts and financial assumptions—not against a sales presentation or the lowest headline price. First establish what the building and public owner need; then check feasibility, compare technical and financial offers, assess the provider and contract, and document how the chosen bid meets the stated goals.
1. Set the project goals and screen the site before inviting bids
Decide what the project must accomplish before selecting a provider. A school may prioritize lower long-term electricity costs, educational value or a roof replacement schedule; another public building may prioritize resilience, emissions goals or minimal disruption. Those priorities should shape the solicitation and scorecard. The National Laboratory of the Rockies (NLR) puts the principle plainly: “The most important aspect of proposal evaluation is correlating a local government agency’s goals to the selection criteria.”
DOE’s Federal Energy Management Program recommends validating a project through pre-screening, site screening, and financial and regulatory screening. Use that work to identify constraints that could make a proposal infeasible, delay construction or change its economics. See DOE FEMP’s photovoltaic procurement guidance.
- Building and site: usable roof or land area, orientation, shading, structural loading, roof condition, roof replacement plans, building changes, access and construction logistics.
- Energy and utility: energy demand, electricity supply contract, tariff, utility relationship, and the likely effect of solar on the building’s overall bill.
- Delivery constraints: permitting, approvals, interconnection, applicable land or building requirements, hazards, and the type of system that fits the site.
- Financial and regulatory constraints: available funding, financing assumptions, incentives and local rules that may affect ownership or a power purchase agreement (PPA).
Give every bidder the same reliable site and energy information. If a roof assessment, utility data or known project constraint is missing, flag the gap in the solicitation and require bidders to identify their assumptions rather than allowing each to fill it differently.
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#1 Best Overall
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2. Write an outcome-based RFP and a scorecard before proposals arrive
An RFP should tell bidders what the owner wants to achieve, what information to provide, and how responses will be judged. EPA defines an RFP as “A formal bid document to ask vendors to provide proposals for desired projects, as required by many public agencies (federal, state, local).” Its Proposals & Solicitations resources include RFP templates and evaluation materials. NLR also advises public agencies to focus on system performance, require certified equipment, provide useful site information, and distribute the solicitation widely; its energy project RFP guidance offers further procurement resources.
Publish the evaluation criteria and any weights in advance, consistent with local procurement rules. There is no universal weighting: the right priorities depend on the owner’s goals, jurisdiction, building condition, utility tariff, funding and procurement requirements. A sample framework to adapt—not a prescribed set of weights—is below.
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| Scorecard category | What to evaluate |
|---|---|
| Project fit | Layout, shading, roof and load condition, anticipated roof work, energy demand, utility tariff, interconnection feasibility and future site plans. |
| Technical response | System size and production assumptions, design approach, certified equipment, codes and standards, safety, performance guarantees, monitoring and maintenance plan. |
| Financial value | For an owned system, total project cost and lifecycle assumptions. For a PPA, price per kWh, escalator, term, bill impacts, transaction costs and assumptions about utility prices and incentives. |
| Provider capacity and delivery | Relevant experience and references, licenses and training, financial strength, staffing, schedule, milestones, responsibility for permits and interconnection, and construction plan. |
| Contract and lifecycle risk | Equipment and roof warranties, operations and maintenance (O&M), availability or performance remedies, insurance and indemnity, system access, renewable energy certificate (REC) ownership, buyout or transfer rights, and end-of-term disposition. |
| Public goals | Any stated priorities such as local sourcing, labor requirements, educational benefits, resilience, speed, emissions or renewable claims, or lowest lifecycle cost. |
Use the same requested response format for all bidders so evaluators can compare equivalent information. A useful RFP response checklist asks each bidder for:
- Proposed scope, system size, design basis and production estimate, including the assumptions behind the estimate or guarantee.
- Equipment details, certifications, applicable codes, warranties, monitoring arrangements and maintenance plan.
- Project schedule, milestones, construction logistics, and who handles permitting, approvals and utility interconnection.
- Provider qualifications, relevant references, proposed staffing and financial capacity to deliver and support the project.
- All commercial terms, responsibilities, risks and contract options relevant to the offered ownership model.
Score proposals against the published criteria and record the evidence for each score. If a response omits required information or relies on a different assumption, mark the gap and request clarification through the same procurement process for all bidders, as local rules allow. Do not let a favorable unrequested claim substitute for a scored requirement.
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3. Check roof condition, building readiness and delivery risk
A roof can determine whether a project is practical on its proposed schedule and whether its financial assumptions hold. Review shading and orientation alongside structural capacity, roof age and condition, expected replacement timing, and compatibility between the installation and existing roof warranties. NLR specifically recommends written certification that installation will not adversely affect the roof warranty, or an equivalent substitute warranty. See NLR’s key elements for solar RFPs.
Require bidders to state what inspections or engineering reviews their proposal assumes, who will arrange them, and how a finding that changes the design, cost or schedule will be handled. Check that the construction plan accounts for access and building operations, particularly where work could affect students, staff, visitors or public services. Compare the proposed schedule and milestones on the same basis, including the bidder’s stated responsibilities for permits and interconnection.
4. Compare direct purchase and PPA offers on the right basis
Ownership changes what counts as a comparable financial offer. In a direct purchase, the public owner funds and owns the system; it may hire a developer to design, procure, install and commission it. Under a PPA, a developer owns and operates the system and the host buys its output under contract. Pennsylvania DEP’s Solar for Schools resources include school-focused materials and pro formas for both direct ownership and PPAs, as well as a ten-step project process spanning team formation, energy assessment, selection, construction, monitoring and maintenance.
| Comparison point | Direct purchase | PPA |
|---|---|---|
| Who owns and operates the system? | The public owner owns the asset; the RFP may select a developer to design, procure, install and commission it. | The developer owns and operates the PV system; the host buys its output under contract. |
| Primary financial comparison | Total project cost and lifecycle value, using consistent output, utility-price, financing and incentive assumptions. | Price per kWh, escalator, contract term, production guarantee, expected bill effects and other transaction costs—not the developer’s internal project costs. |
| Key allocation questions | Who is responsible for financing, O&M, performance, warranties, insurance, system access and end-of-life work? | Who is responsible for O&M and performance, and what are the host’s obligations and remedies under the contract? |
| Rights to examine | Clarify any contractor obligations and the owner’s responsibility for monitoring, maintenance and disposition. | REC ownership, buyout, transferability and end-of-term choices, including the associated conditions and costs. |
Model each offer using shared assumptions for system output, utility prices, incentives, financing and project costs where applicable. For a PPA, analyze the whole building bill and contractual obligations, not only the first-year per-kWh price. EPA notes that PPAs can avoid upfront capital and shift operating and performance risk, but can add negotiation complexity and administrative cost, including when solar does not cover all site demand. EPA describes PPA terms as typically six to as long as 25 years, and annual escalators as often in the 1–5% range; those are general source-described ranges, not a forecast or a benchmark for a specific bid. Validate the actual terms and local conditions. See EPA’s solar PPA guidance.
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5. Review PPA pricing, guarantees, RECs and exit terms
A PPA’s headline price does not describe the full deal. Compare each offer’s price per kWh and escalator alongside the production guarantee, contract term, allocation of maintenance and performance responsibility, and remedies if promised performance is not achieved. Confirm how the proposal interacts with the utility relationship and the building’s remaining electricity needs.
Read the REC provisions carefully. EPA explains that REC ownership affects what renewable-energy claims a host can make. The contract should state who owns the RECs and what environmental claims the public owner may make. Also examine buyout rights, transferability and end-of-term choices; compare their conditions and costs rather than treating a stated option as a guaranteed, cost-free exit. Terms and applicable rules vary by jurisdiction. EPA’s PPA guidance discusses these contract considerations.
6. Check jurisdiction and procurement requirements before award
Utility tariffs, net metering, interconnection requirements, incentives, PPA legality, REC markets, permits and public procurement approvals vary across states, utilities and localities in the United States. Have the relevant utility and procurement or legal staff validate assumptions before bids are scored or an award is made; do not import another jurisdiction’s tariff or contract assumptions.
There is also a time-sensitive England-specific rule for schools and colleges. UK Department for Education guidance published on 16 July 2026 says that, from 15 July 2026, school-estate PPAs must use the DfE PPA and land-lease template under its stated approval process. The pilot covers up to 150 institutions in Yorkshire and Humber, East Midlands, and South East, with procurement described as beginning in autumn 2026. This does not apply to U.S. projects or establish requirements elsewhere. Check the live DfE guidance for current scope and process.
7. Make the award decision traceable
A defensible selection connects the owner’s stated goals to the criteria, the proposal evidence and the resulting scores. Keep the evaluation record clear enough that a reviewer can see why a bid ranked well, where it did not meet requirements, and how material assumptions or contract risks affected the decision. Public owners can adapt official tools rather than starting from an empty page: use EPA’s RFP resources, NLR’s public-sector RFP guidance, and Pennsylvania DEP’s school pro formas where applicable. Apply each tool in line with the owner’s jurisdiction and procurement rules.
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