Actual building context
Address-based imagery and roof geometry—not a generic square-foot calculator.
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We use your location to provide localized solar offers and incentives.
We serve MA, NH, CT, RI, ME, VT, NJ, PA, and TX
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Free commercial solar site estimator
Enter one building address. See a site-specific roof layout, panel count, system size, annual production range, and data confidence—before sharing contact details.
Free roof fit check
Enter one commercial property address. We automatically analyze the roof, keep planning clearances around mapped equipment, and estimate how much solar may fit.
Anonymous result includes
No account required to see your roof layout. Cost and verified incentive matches unlock after work-email verification.
Direct answer
Panel capacity depends on usable roof geometry, fire-access paths, rooftop equipment, row spacing, and racking—not gross roof area alone. In our Woburn worked example, the engine places 873 620-watt panels on 35,394 ft² of usable roof area, producing a 541.3 kWdc layout—about one panel per 40.5 usable ft². Your building may differ, so enter its address for a site-specific layout.
Address-based imagery and roof geometry—not a generic square-foot calculator.
Preliminary perimeter, access-path, and equipment keep-out geometry.
A fixed commercial module and rack concept optimized for panel count.
A visible data grade, warnings, and a manual-review path when automation is insufficient.
Server-rendered worked example
This sample is generated from the same layout engine used by the estimator, using a mapped warehouse planning area and modeled rooftop objects. Production uses a Massachusetts regional planning factor for the crawlable example.
Read the warehouse solar ROI guideExample only; not a proposal or construction design. 1,210 kWh/kW-year planning factor for MA. The band shown is the model’s own planning range around 654,925 kWh. A live result uses address-specific geometry and uses site production modeling when available.
Methodology and boundaries
Reviewed by NuWatt Engineering Team · Updated August 2026
Module specifications come from the Heliene 620 W manufacturer datasheet. Production uses the NREL PVWatts model when configured and a disclosed regional planning factor as fallback. Incentive matches use NuWatt’s versioned official-source registry and remain conditional until project facts are verified.
NuWatt commercial project review is available in Massachusetts, New Hampshire, Maine, Vermont, Rhode Island, Connecticut, New Jersey, Pennsylvania, and Texas.
The answer depends on usable roof area, module dimensions, access pathways, rooftop equipment, roof orientation, and the preliminary racking layout. NuWatt’s estimator measures those planning constraints for the selected building and returns a site-specific panel count and DC system size.
No. It is a preliminary feasibility layout. A site survey, structural engineer, racking manufacturer, roofing professional, utility, and permitting authority must verify the final design, ballast or attachments, electrical scope, and interconnection.
The anonymous result includes the aerial roof view, a maximum-panel planning layout, panel count, system size, annual production range, and a data-confidence grade. Installed cost, current official-source incentive matches, and a private report unlock after work-email verification.
The estimator offers a manual commercial roof review instead of ending the session. Imagery gaps, attached structures, and unusual roof geometry are common reasons an automated result may need human review.
Gross roof area includes space that may not be usable for solar. A credible panel count must account for the actual roof boundary, access paths, setbacks, rooftop equipment, module dimensions, row spacing, and the proposed racking geometry.
You can see the preliminary installed-cost range, likely incentive programs, and a shareable feasibility report. Verification uses one work email and a one-time code—no phone number or account is required, and verification alone does not add you to a marketing list.