Technology
The three pillars of bankability
A lender's engineer asks three questions of every solar project. Solesca answers all three from the same design, the same way every time.
NREL SAM
One of three yield engines, with SolarFarmer and Solesca Pro, chosen per run
DNV SolarFarmer
A second simulation from the same design
1%
Yield agreement with PVsyst
ECA Power’s published case study
Which question does each pillar answer?
Pick a pillar to see the question it answers and what runs it inside Solesca.
Is the site data right?
Every design starts from imagery, terrain, equipment and weather that trace to a named source your engineer can check.
- Imagery: Google Maps, Google Photorealistic 3D Tiles for rooftops, Bing, ArcGIS, and Nearmap with your subscription
- Overlays: KML files from Google Earth or a layout tool
- Terrain: 10 meter GPXZ bare-earth elevation, worldwide
- Equipment: the California Energy Commission library, or your own PAN and OND files
- Weather: SolarAnywhere through an API key, or the weather file your financing partner expects
Will the energy model hold up in diligence?
Solesca yield simulations validate within 1% of PVsyst, corroborated by ECA Power’s published case study.
- Yield engine: the System Advisor Model from NREL (now the National Laboratory of the Rockies)
- Near shading: Solesca’s own algorithm, fed into SAM
- Second simulation: DNV SolarFarmer runs inside Solesca through DNV’s API Partner Program, in 2D, unlimited on the Engineering License
- Diligence handoff: the native PVsyst PVC export carries the full shade scene
Will the design pass code?
Engineering mode builds the project from modules to the point of interconnection, and every component is checked against the NEC.
- Wire sizing: the minimum code-compliant size or one you set, upsized until string loss falls under your cutoff
- Rapid shutdown: NEC 690.12 by optimizer, exemption or microinverter
- Wire losses flow back into the yield, so the model runs on the design engineering approved
- Outputs: a bill of materials, and a stampable plan set as an Engineering License add-on
Where does each pillar stop?
A reviewer trusts the limits you name. These are ours, published so you do not find them in a demo.
- Site data
- Terrain data is neither survey grade nor construction accurate. It is for layout decisions before the survey, and the survey still governs construction.
- Energy model
- SolarFarmer 2D does not support east-west racking or dual-axis tracking, cannot mix fixed-tilt and single-axis tracker arrays in one run, and needs one tilt and azimuth per inverter.
- Engineering
- Solesca does not stamp. It produces a stampable set, and a licensed engineer of record signs it.
Common questions
What does bankability depend on?
Bankability is the confidence a lender’s independent engineer places in a project. It rests on three pillars: the site data the design starts from, the energy model that turns the design into a yield, and the engineering that shows it can be built to code.
It behaves like a product, not a sum. A precise yield model on the wrong ground is worth nothing, and so is a clean layout that fails code review. The weakest pillar sets the confidence in the whole project, which is why a design tool has to carry all three.
How does Solesca make the answer repeatable?
Design templates and engineering templates let your engineers set the rules once, including racking products for terrain, and every project after that starts from them. Sales and engineering run the same engine on the same inputs, from feasibility to diligence.
Before Solesca, ECA Power’s sales and engineering sizings differed by 15 to 50 percent on the same project. Their published case study reports a 50 percent increase in design accuracy across the 900+ projects they ran through the platform in 2024.
Which integrations sit under each pillar?
Every source named on this page, in one table.
| Pillar | Input | Source |
|---|---|---|
| Site data | Imagery | Google Maps, Google Photorealistic 3D Tiles, Bing, ArcGIS; Nearmap by subscription |
| Site data | Overlays | KML from Google Earth and layout tools |
| Site data | Terrain | GPXZ bare-earth elevation, worldwide |
| Site data | Modules and inverters | California Energy Commission library; PAN and OND upload |
| Site data | Weather | SolarAnywhere API; custom weather file |
| Energy model | Yield simulation | NREL System Advisor Model (SAM) simulation core |
| Energy model | Independent simulation | DNV SolarFarmer 2D |
| Energy model | Diligence handoff | Native PVsyst PVC export |
| Engineering | Code check | Every component checked against the NEC |
| Engineering | Outputs | Wire sizes and losses, bill of materials, plan set add-on |
Why does Solesca run on SAM?
Because a reviewer can inspect it. The System Advisor Model is free and openly documented, and its simulation core has been Solesca’s energy model since 2023. Solesca adds its own near-shading algorithm and passes the result into SAM.
Is the 1% validation an independent third-party study?
The public corroboration is ECA Power’s published case study, together with the NREL cooperative research agreement, CRADA CRD-23-23746, and the DNV SolarFarmer partnership. A formal methodology publication is not yet posted.
The comparison is reproducible either way: the PVC export lets you rebuild any Solesca design in PVsyst and check the agreement yourself. Onyx Renewables cut their time from design to a PVsyst-ready model by 50 percent once they stopped rebuilding the shade scene by hand.
How can you verify it on your own project?
Pick a project you have already built and whose numbers you have signed. Model it in Solesca, export the PVC file, and open the same scene in PVsyst. The comparison takes an afternoon, and unlimited projects means the test costs time rather than budget.
We would rather you run that test than take any figure from this page. If you want company for the first pass, our engineering team will run it with you.
Does Solesca replace PVsyst?
No. Solesca works upstream of PVsyst and exports to it natively. Many teams keep PVsyst as the simulation of record for financing, and the PVC export means that handoff is a file, not a rebuild.
How accurate is the terrain data?
Terrain tracking uses 10 meter GPXZ bare-earth elevation data, available worldwide. It is neither survey grade nor construction accurate. It is meant for layout decisions before a survey, and the survey still governs construction.
Where can I read the CEC review?
The California Energy Commission published the staff certification review at energy.ca.gov in August 2025. It recommends the Solesca tool for certification under the 2022 Energy Code.
Test all three pillars on a project you know
Book 30 minutes with our U.S.-based engineering team and bring a project you have already built. We will model it live, and you can hold the result against the numbers you signed.