Solar PV design software: 40 tools, free and paid, by use (2026)

By The PV Index · Published 30 October 2026 · Last updated 30 October 2026. Counts as of 2026-11-02.

The PV Index lists 40 solar PV design and simulation tools from 16 countries: 8 free, 4 freemium and 28 paid. They fall into four groups: residential design and proposal tools (10), commercial and utility-scale layout software (10), energy yield simulators (9) and free calculators and configurators (8). The United States has the most (14), and 19 come from Europe.

There is no single best solar design software: the right tool depends on what you design (a house roof or a 200 MW plant), what you need out of it (a sales proposal, construction drawings or a bankable yield report) and your budget. This guide groups every design tool in the directory by job, with its pricing model and a one-line summary taken from its listing. Each name links to a listing page with the official website.

Jump to: Residential · Commercial · Energy yield simulation · Free tools · Other design tools · free solar design software · PVsyst alternatives · by country · how to choose

Residential and commercial design and proposal tools (10)

For installers who need a roof layout, shading, a production estimate and a customer proposal in one place.

Commercial and utility-scale layout and engineering (10)

For EPCs, developers and engineers laying out larger rooftops and ground-mount plants, often inside CAD.

Energy yield simulation (9)

For engineers, independent engineers and lenders who need detailed or bankable production estimates.

Free calculators, open-source tools and manufacturer configurators (8)

For quick estimates, research and system sizing without a licence.

Other design tools (3)

For specialist design and simulation tools.

Free solar design software

8 tools in this guide are listed as free: Fronius Solar.creator, Global Solar Atlas, OpenSolar, PVGIS, pvlib python, PVWatts Calculator, Sunny Design and System Advisor Model (SAM). Another 4 are freemium (a free tier with paid options): LandGate, Lyra Solar, PlantPredict and RETScreen Expert.

Free tools are good for first estimates, research and sizing, and manufacturer configurators are free because they size systems around that manufacturer's own inverters. For customer proposals with your branding, permit plan sets or bankable reports you will usually need a paid tool, or a free platform that earns money another way (check each listing's description).

PVsyst and its alternatives

PVsyst: Industry-standard PV simulation software for detailed energy yield studies, shading analysis and bankable P50/P90 reports. Other tools in the directory that model energy yield in detail include SolarFarmer (DNV), PlantPredict, PV*SOL premium, Solar Pro, archelios Suite, System Advisor Model (SAM) and pvlib python. Of these, PlantPredict, System Advisor Model (SAM) and pvlib python have a free or free-tier option. If a lender or independent engineer will review the report, ask early which software and weather data they accept.

Production estimates are only as good as the weather data behind them. Our Software category also lists solar resource datasets (Resource Data & Forecasting) used inside these tools.

Ownership changes

Several tools have changed owner in recent years, which can affect pricing, support and integrations. Listings that mention an acquisition: HelioScope, Lyra Solar, PlantPredict, PVcase, RatedPower pvDesign and Solargraf. Details are on each listing page.

Solar design software by country

How to choose solar design software

1. Start from the output you need. Installers selling to homeowners need a fast layout, a production estimate and a proposal; EPCs need layouts, stringing, cable runs and drawings; financiers need a yield report they trust. Pick from the matching group above.
2. Check local data and rules. Make sure the tool has weather data for your sites, the module and inverter models you buy, and your local tariffs, incentives and permitting formats. Some tools above are built for one market (check the listing).
3. Test shading on a real project. Run the same roof or site through two tools and compare the shading losses and yearly production. Large differences tell you to look at the inputs.
4. Compare the pricing model. Tools are sold per user, per project or as a desktop licence, and some free platforms are paid for by hardware or finance partners. Estimate your yearly cost at your real project volume.
5. Look at the workflow around design. Many residential tools add CRM, proposals and e-signatures; utility-scale tools add CAD export and terrain models. Check exports (PDF, DXF, PVsyst files) and integrations with what you already use.
6. Ask about training and support in your language and time zone. Our Education category lists PV design courses, including software training.

Method

Tools come from the Software category of The PV Index: every listing typed Design & Simulation, plus the free calculators and data tools under Free Tools that are used for system design. Pricing (Free, Freemium, Paid) and descriptions are from each listing, compiled from the vendors' own websites. Order within each group is not a ranking. Missing a tool? Submit it for review.

Related guides: Upcoming solar trade shows and conferences by month and region, with dates and cities. · Every solar and renewable energy trade association in the directory, national and global, by region and country. · Every solar EPC contractor in the directory, by region and country, with utility-scale, C&I, storage and off-grid specialists. · Every solar distributor and wholesaler in the directory, by region and country, and how installers choose one.

More: all guides · browse by country · submit a listing (free)