Solar Engineering Services

What Is a Solar Feasibility Study (And When Do You Actually Need One)?

A solar feasibility study is an engineering report that tells you, before you spend serious money, whether a solar or solar-plus-storage project on your specific site will technically work and financially pay off. It combines a site assessment, a preliminary energy model, an interconnection check, and a financial summary into a single go/no-go recommendation.

If you're a commercial property owner, a developer scouting sites, or an EPC bidding work, the feasibility study is the cheapest insurance policy you'll buy on a project. The cost is usually less than 1% of the eventual installed system, but it can save you from spending six or seven figures on a site that fails at interconnection, fails at structural review, or simply never breaks even.

In the Gulf Coast specifically - where hurricane wind loading, utility interconnection queues, and roof age all materially affect a project - a feasibility study is rarely optional. Solar Alternatives Engineering has run more than 1,800 of these for clients across all 50 states.

What's actually inside a solar feasibility study?

A complete feasibility study includes:

• Site assessment & shading analysis — sun-path modeling, obstruction mapping, and an annual shading loss percentage.
• Preliminary single-line diagram — the proposed electrical architecture from PV array to point of interconnection.
• Interconnection feasibility review — utility queue check, hosting capacity review, anticipated upgrade costs.
• Preliminary energy model — yield in kWh/year using PVSyst, HelioScope, or Aurora Solar.
• High-level financial summary — installed cost estimate, payback period, NPV, IRR.
• Risks and a written go/no-go recommendation — with the specific dealbreakers identified.

When do you need a feasibility study?

You need one before you sign anything other than an NDA. Specifically:

• ▸ Before purchasing a property you plan to put solar on.
• ▸ Before responding to an RFP as a developer or EPC.
• ▸ Before allocating capital in your CapEx budget for a solar project.
• ▸ Before applying for incentives or financing that require an engineering basis.
• ▸ Before signing a PPA, so you know the system actually delivers what you're promising.

You don't need a separate feasibility study if you already have a recent (under 12 months old) PE-stamped study from a qualified firm, or if the project is small (<25 kW) and the site is unambiguously good.

How long does it take and what does it cost?

• ▸ 2 to 4 weeks for a complete study, depending on utility response on the interconnection request.
• ▸ A fraction of a percent of the eventual installed cost — far less than the cost of a single site visit by a contractor.
• ▸ A 5-to-10-page report with energy yield numbers, single-line, financial summary, and a clear recommendation.

Common reasons a project gets a "no-go" recommendation

These are the actual reasons we issue no-go recommendations on Gulf Coast and nationwide projects:

1. 1Roof age — less than 10 years of remaining useful life means the array will outlive the roof, and the array has to come off when the roof is replaced. This kills the economics.
2. 2Wind zone classification — coastal Louisiana, Florida, and Texas projects often need ballast or attachment systems that can double the structural cost.
3. 3Utility hosting capacity exceeded — substation already at its DER limit, requiring a multi-million-dollar upgrade allocated to your project.
4. 4Shading from existing or future structures — neighboring building permits already filed for taller construction.
5. 5Available roof area too small for meaningful offset — the system will be installed but never pay back.
6. 6Service entrance / MDP capacity too low — needs a transformer or service upgrade that wasn't budgeted.

Why interconnection feasibility is the most underrated section

In our experience, the interconnection review is where 4 out of 5 surprise no-go recommendations come from. Energy yield modeling is mostly a solved problem - modern software gives reliable answers. But utility interconnection queues, hosting capacity, and required upgrade studies vary so dramatically by utility and substation that you cannot predict them from the outside.

We've seen identical 1.5 MW projects on adjacent properties get wildly different fates:

• ▸ One: approved with no upgrade cost and a 90-day study.
• ▸ The other: held in queue for 18 months and assessed a $2.4M transformer upgrade.

The difference was which substation feeds the property. A feasibility study catches this in the first three weeks of the project, not after you've sunk money into design.

Feasibility study vs full design vs owner's rep

A feasibility study is not the same as IFP (Issue for Permit) or IFC (Issue for Construction) drawings. Here's the difference:

How to choose a firm to do your feasibility study

Three quick filters:

• 1Licensed PE on staff in your project state — Without one, the study can't be stamped or carry weight in permitting.
• 2Software competency in PVSyst, HelioScope, or Aurora Solar — listed on the firm's website. If they only mention spreadsheets, walk away.
• 3A track record in your market segment — community solar, C&I rooftop, microgrid, and carport each have specific gotchas.

Solar Alternatives Engineering is NABCEP-PVIP certified, BBB Accredited, an AMICUS Solar Cooperative member, and a design partner for Tesla, SPAN, FranklinWH, SMA, SolarEdge, and EG4. Headquartered in New Orleans, Louisiana, serving clients in all 50 states.

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