Will solar pay off for your roof?Get the honest figures.
Free calculator turns your roof into payback, NPV, IRR and CO₂ savings, built on official PVGIS and NASA data. No email wall, no sales calls. Installers get the same engine as a widget and API.
Always free for homeowners. No sign-up, no email wall, no sales calls. · or try the developer API
Free, no sign-up, no email wall. Payback, NPV, IRR and CO₂ on real PVGIS data.
Two ways to ship it
Same engine, two front doors. Choose by who's building.
Drop-in Widget
Paste one snippet on any site: WordPress, Wix, Webflow, Shopify or plain HTML. A polished calculator with address search, charts and lead capture, white-labelled to your brand.
- ✓ No engineering: copy, paste, done
- ✓ Matches your site's look (auto-theme)
- ✓ Captures leads straight to you
REST API
Three endpoints (yield, economics, geocoding) with resale-friendly licensing. Build your own UI, run batch portfolios, or wire it into your product. cURL, JS, Python, TS.
- ✓ Full pipeline: kWh → NPV, IRR, payback, CO₂
- ✓ Resell the results, no per-seat asterisks
- ✓ Typed responses, examples in 4 languages
Resale-OK data
Yield and pricing data you are licensed to resell. Build it into your product, white-label it, ship it to customers. No per-seat asterisks.
Economics built-in
More than kWh. You get NPV, IRR, simple and discounted payback, lifetime savings and CO₂: the numbers that close a solar deal.
Embed anywhere
A drop-in widget for every stack: React, Vue, Svelte, WordPress, Drupal, Shopify, plain HTML, or a framework-free web component. Capture leads straight from it.
A real, live widget
The same engine, white-labelled and embedded on an installer's own site.
Try a real call ☀️
This runs an actual POST /public/estimate on a sample 6 kWp roof in Zürich. Real PVGIS data, no key and no sign-up.
curl -X POST $API/public/estimate \
-H "Content-Type: application/json" \
-d '{"lat":47.37,"lon":8.54,"kwp":6,"tilt":35,"azimuth":180,"country":"CH"}'This runs the fixed sample roof. The playground runs the same pipeline on any roof you enter.
Hit “Run the demo” to see payback, NPV, IRR & CO₂ for the sample roof.
Embed it in whatever you build with
Every adapter is a thin wrapper around the same server-gated widget. Your key, your tier, the same leads. Add a new platform without touching the backend.
@solar-api/react@solar-api/vue@solar-api/svelteplugin + shortcodeblock moduletheme app block<solar-widget>copy-paste iframeShip solar ROI this afternoon 🚀
Grab a free key, paste the widget, and start capturing leads. Upgrade when you're ready to white-label.