Credits

This simulator measures nothing itself: it computes on data others have produced, open and free, and rests on a few free-software libraries. Here is which, what they do here, and on what terms they are reused.

The climate data

The typical weather year — irradiance, temperature, wind, hour by hour, along with the altitude of the point — comes from PVGIS, the Photovoltaic Geographical Information System of the European Commission, Joint Research Centre (JRC). PVGIS © European Union. Reuse is permitted provided the source is cited; the data is supplied as it stands, without warranty, and this site in no way commits the Commission. PVGIS terms of use.

The temperature normals used to correct the altitude of the weather grid cell come from Open-Meteo, which redistributes the ERA5 reanalysis of the Copernicus Climate Change Service (C3S) and the ECMWF, brought back down to the site's altitude. Data under the CC BY 4.0 licence, free for non-commercial use and with no account.

The map and addresses

The base map, the address search and the name suggested for a placed marker all come from OpenStreetMap: the tiles from the OpenStreetMap Foundation's server, the search and the reverse geocoding from its Nominatim engine. One single database, maintained by tens of thousands of volunteers.

© OpenStreetMap contributors, data under the ODbL 1.0. Legal notices and licence licence. These services are offered free of charge: the site spaces out its requests and remembers what it has already asked for, so as not to weigh on a common good.

The libraries

Next.js · MIT
the site's framework — pages, server rendering, form actions
React · MIT
the interface and how it reacts
Leaflet · BSD 2-Clause
the location map — drag, zoom, place the marker
Tailwind CSS · MIT
the styling

The server itself runs on Node.js (MIT), and the site is built with TypeScript, ESLint and Vitest: free software too, but they never reach your browser.

The MIT and BSD licences permit this use with nothing in return but keeping the notice — which is what this page is for. Their full text is available from each of these sites.

What is borrowed from nobody

The simulation engine — the path of the sun, module efficiency, battery regimes, building and thermal-battery thermics —, the year chart and the PDF report generator are written for this site, by hand, with no library. No font is downloaded: the text is shown with the ones on your device.

Audience measurement

Google Analytics, loaded through Google Tag Manager, and only after you accept on the banner: if you decline, nothing is written into the page. The details are on the Privacy page.

The site itself

Solar and Heating Simulator, designed and built by Florent Devaux. Provided free of charge, as a courtesy, with no warranty at all as to the results: a simulation is not a sizing, and does not replace an installer's advice.

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