A solar feasibility study evaluates whether a proposed solar project is technically practical and commercially worth developing. It brings together site conditions, expected generation, electrical connection requirements, costs and the owner’s objectives. Its purpose is to support a decision about the next stage of work—not to promise final approval, a fixed installation price or a guaranteed return.
For a commercial property, usable roof or land area is only the beginning. Electricity use, ownership rights, building condition and the grid connection can determine whether an apparently attractive project is workable.
The questions a study should answer
A useful study begins with a defined objective. A business seeking lower purchased energy has a different decision from a developer selling generation or a facility prioritizing resilience.
| Area | Main question |
|---|---|
| Site | Is suitable space available, with acceptable shading, access and physical conditions? |
| System concept | What layout and capacity basis are being evaluated? |
| Generation | How much electricity might the system produce, and what assumptions drive that estimate? |
| Electrical connection | What connection path and infrastructure need investigation? |
| Commercial model | How will generation create value under the actual electricity arrangement? |
| Delivery risks | Which approvals, ownership issues or investigations remain unresolved? |
The IFC utility-scale solar developer guide describes feasibility as an integrated review of the site, concept, yield, connection, permitting and economics. Its historical international context is useful for project structure, not current local permitting or incentive eligibility.
Generation estimates need visible assumptions
Solar production modeling uses location, orientation, tilt, equipment and loss assumptions. Shading, availability, temperature effects and the relationship between DC array capacity and AC inverter capacity can affect the result.
PVWatts provides preliminary estimates of grid-connected PV production. Its own limitations explain why a simple model should not be mistaken for a detailed engineering design or a guaranteed annual output.
Ask whether a result is based on representative weather, a particular historical year or another dataset. Also ask what the output boundary is: energy leaving the inverter is not necessarily identical to energy delivered at the project’s revenue meter.
Annual consumption can hide the important mismatch
An illustrative warehouse uses substantial electricity over a year but operates mainly at night. A solar layout sized to match annual consumption may produce a large share of its energy when the warehouse is using little power.
That does not make solar unsuitable. It means self-consumption, export treatment, storage possibilities and the applicable tariff need to be modeled. A second warehouse with the same annual total and daytime operations can have a different commercial result.
For commercial projects, interval electricity data is therefore more useful than an annual total alone. The study should also account for planned changes such as electrified equipment, new tenants or EV charging.
A study should expose uncertainty
Separate confirmed facts from assumptions. A roof may appear suitable but still require structural review. A preliminary connection discussion may identify a possible path without establishing the cost or approval date. A concept layout may need revision after a detailed survey.
An effective report lists those open issues and explains what evidence resolves them. This lets the owner spend on the next investigation for a reason instead of treating every early estimate as settled.
Cost comparisons should identify included construction, equipment, connection work, professional services and ongoing costs. Any incentive assumption needs current, project-specific verification. A feasibility result should remain understandable without an unsupported tax-credit promise.
What to collect before commissioning the study
Provide electricity bills and interval data if available, property and roof information, available electrical drawings, operating schedules and planned changes. Identify who controls the property and who buys the electricity; they may be different parties.
Also state the decision the report must support. An early screen to choose among sites needs a different level of detail from an investment approval package. Agree that depth before comparing fees.
Match the study depth to the decision
A feasibility study can support several different decisions. An owner comparing properties may need an initial screen that identifies obvious constraints and the investigations most likely to change the result. An owner seeking investment approval needs a more developed understanding of costs, risks, expected production and delivery conditions.
The scope should name the decision and the evidence needed to support it. Without that agreement, a technically competent preliminary report can disappoint a buyer who expected a construction-ready design. The reverse is also possible: a detailed investigation may be unnecessary when an early screen would reveal that the site does not meet the owner’s basic requirements.
Ask which assumptions are acceptable at the proposed stage. A conceptual layout can be appropriate for comparing options, provided the report explains that it may change. An unresolved connection cost can be modeled as a range or scenario, but it should not disappear into a precise-looking total.
The value of feasibility lies in improving the decision. The best next step may be to advance the project, revise the concept, investigate a specific risk or stop spending on an unsuitable option.
Property control can be as important as available space
A solar project needs a workable relationship between the proposed installation and the parties controlling the property. Ownership, lease conditions, access rights and future use can affect whether the concept is deliverable. These issues should be identified early and referred to the appropriate commercial or legal adviser where necessary.
For an illustrative leased building, the electricity customer and the roof owner may be different organizations. A favorable generation estimate does not establish permission to use the roof or explain who carries obligations when the tenancy changes. The feasibility study should identify those interfaces rather than assume one party controls every decision.
Similarly, a ground-mounted concept may need access and construction arrangements beyond the panel area. An available parcel outline does not by itself establish that equipment can be delivered, drainage addressed or connection works completed.
The report need not resolve every legal issue at an initial stage, but it should state which rights or agreements remain to be confirmed and why they matter to the preferred concept.
Roof, land and parking sites have different constraints
A rooftop project needs to consider the existing building and roof assembly, including condition, structural questions, access and the relationship between the solar installation and future roofing work. A large roof area is not the same as an area that can be used without restriction.
A ground-mounted project introduces questions about terrain, geotechnical conditions, drainage, access and the physical connection route. A solar carport adds parking circulation, structural supports and the interaction between construction and vehicle use. Each option requires a concept appropriate to its setting.
Compare alternatives using consistent assumptions about capacity, production boundary and included work. A lower apparent cost for one site may omit an unresolved civil or electrical requirement. The study should identify those differences rather than make unlike concepts appear directly comparable.
An owner with several possible installation areas can benefit from a simple constraints map. It should show what is known, what is provisionally excluded and where further investigation could change the usable area. That is more useful than filling every available surface with a conceptual array.
Production estimates should identify their modeling boundary
A generation estimate needs a stated system configuration and output boundary. Array DC capacity, inverter AC capacity and energy at the point of delivery describe different quantities. The study should specify which one appears in each table and calculation.
PVWatts is useful for preliminary production estimates, but its output still depends on the user’s assumptions and the tool’s modeling scope. A feasibility report should explain why the selected orientation, tilt, equipment assumptions and losses are reasonable for the concept being evaluated.
Ask how shading is treated and whether a more detailed assessment is needed. A broad location-based estimate may be useful for screening, while a particular roof or site can have obstructions that require closer analysis. The level of precision claimed should match the information used.
Do not confuse a modeled annual total with a guarantee. Weather, system condition and operating constraints can cause actual production to differ. A useful report explains the important sources of uncertainty and the next evidence that would improve confidence.
The connection route can reshape the project
A solar installation must connect through an arrangement suitable for the site and the relevant utility or provider requirements. The distance to an apparent connection point is only one factor. Available equipment, protection, permitted operating arrangements and required studies can affect the scope.
An early discussion can identify a possible path without establishing final acceptance or cost. Keep that distinction visible. The feasibility report should describe what connection information is confirmed, what is preliminary and what remains within an external process.
For an illustrative commercial site, a concept may initially assume connection near an existing electrical room. Further review may reveal that additional equipment or a different route needs evaluation. The generation model can remain attractive while the delivery scope changes materially.
Treat that possibility as a reason to investigate the interface early, not as a reason to ignore it until design. The study should identify connection questions that could alter the preferred layout, capacity or business case.
Electricity value depends on when and where energy is used
The financial value of solar production is not determined solely by its annual energy total. The timing of generation relative to site use and the treatment of exports affect how that energy creates value. The actual tariff and contractual arrangement must support the analysis.
An illustrative building with daytime operations may use a larger share of solar output directly than an otherwise similar building with mostly nighttime demand. The difference can matter even if their annual electricity consumption is equal. Storage or changed operations may be worth examining, but they introduce their own costs and constraints.
A report should separate self-consumed production, exported production and any curtailed or otherwise unavailable energy within its model. It should also explain the value assigned to each relevant category. An assumption that every generated kilowatt-hour offsets the same charge can misrepresent the project.
If the assessment depends on an incentive, credit or special program, identify the current authority and project-specific eligibility evidence. Do not use a historical program description as a substitute for verification.
Build a cost scope that matches the concept
A preliminary cost estimate should identify what it includes. Solar equipment and installation may be only part of the project. Depending on the site, the concept can also involve roofing, structural work, civil work, electrical changes, connection work, professional services and owner costs.
Separate known scope from allowances for unresolved items. An allowance can be useful when a particular uncertainty has not yet been investigated, but its purpose should be clear. It should not create the impression that the underlying condition is confirmed.
Operating costs and future responsibilities belong in the comparison as well. Monitoring, maintenance, access and equipment-related obligations should be considered within the chosen ownership or procurement model. A low initial price does not describe the complete economic picture.
Ask whether competing concepts use the same cost boundary. If one includes a roof replacement and another assumes the existing roof remains suitable, explain that difference before presenting a preferred option. The owner needs to understand what each investment actually delivers.
Use sensitivity analysis to identify the next useful investigation
A feasibility study often contains uncertain inputs. Sensitivity analysis examines how the conclusion changes when those inputs vary. Its purpose is to show which assumptions deserve attention, not to make uncertainty disappear through a more elaborate spreadsheet.
For example, a project might remain attractive across a reasonable range of production assumptions but be highly sensitive to an unresolved connection cost. In that case, additional connection investigation may be more useful than refining an already adequate preliminary energy model.
The report should identify the basis of its scenarios and avoid presenting them as measured forecasts. A conservative case, a central case and another defined scenario can help an owner understand the decision, provided the differences are explained.
The final recommendation should connect the analysis to action. Identify the preferred concept, the conditions supporting it, the unresolved issues most likely to change it and the next work needed. A feasibility study earns its value when the owner can explain why the project should advance and what must be learned before the next commitment.
Common questions
Is feasibility the same as a site survey?
No. A survey supplies physical information. Feasibility uses site information alongside electrical, production and commercial analysis to evaluate a project.
Does it include the utility’s interconnection study?
Not automatically. The utility or relevant provider may require a separate process. Clarify what connection analysis is included and what remains external.
Is a favorable result permission to build?
No. Detailed design, required permits, connection agreements and other approvals remain separate steps.
What should the final recommendation look like?
It should explain the preferred concept, key assumptions, remaining risks and recommended next investigations. “Solar is viable” without those boundaries is not enough for an informed investment decision.
Start with the business objective
Discuss your site, electricity use and project goals with Soleil Energy’s renewable energy team. For larger development projects, the utility-scale solar service provides the relevant delivery context.
Project requirements depend on the site, equipment and applicable rules. Confirm design and installation decisions with the appropriate qualified professional.
