Solar Panels Calculator

GIS, Simulation

Free
No Download/Install required
No registration

https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html#api_5.2

Select you location on a world map, define your solar panels mounting style and orientation, and it will calculate the power produced over the day, month or year. Uses various GIS databases and models.

The PVGIS API 5.2 provides programmatic access to the European Commission’s Joint Research Centre solar resource and photovoltaic (PV) performance databases, enabling automated retrieval of high-resolution meteorological and energy data. It delivers granular datasets including hourly solar irradiance, ambient temperature, and wind speed, alongside calculated PV power output for grid-connected and stand-alone systems. The service supports technical workflows through:

Typical Meteorological Year (TMY) generation for building and energy simulations.
Site-specific horizon profiles to account for topographical shading effects.
Performance estimates adjusted for specific PV technologies like Crystalline Silicon and Thin-film.
Programmatic endpoints for JSON, CSV, and XML data integration into external applications.

Tip: this tool has been derived into several variants by many commercial sites and can therefore look familiar.

Disciplines: Solar energy, Electrical engineering, Architecture, Energy consulting, Civil engineering.

Free alternative to PVsyst, Helioscope, SAM, PVWatts.

Solar Panels Calculator compared with PVsyst, HelioScope, SAM and PVWatts
Solar Panels Calculator (PVGIS API 5.2)	PVsyst	HelioScope	SAM	PVWatts
Tools and outputs: Endpoints for grid-connected and tracking PV (PVcalc), off-grid PV (SHScalc), monthly and daily radiation, hourly radiation series, typical meteorological year and horizon profile. Output comes as CSV, JSON, or EPW for the TMY tool.	Tools and outputs: Modelling of system type, weather data, geometry and loss assumptions for PV projects, aimed at bankable yield studies.	Tools and outputs: Design of commercial solar systems with production estimates and system size optimisation. Lenders cited by the vendor use its estimates in underwriting.	Tools and outputs: Time-series simulation of power system performance together with annual pro forma cash flow, so it covers techno-economic questions for renewables beyond PV yield.	Tools and outputs: Simplified estimate of PV energy production. Version 8 adds bifacial modules, monthly soiling and snow loss inputs and an optional albedo input.
Weather and radiation data: Selected with the raddatabase parameter: PVGIS-SARAH3 for Europe, Africa and Asia, PVGIS-NSRDB for the Americas between 60 N and 20 S, and PVGIS-ERA5. COSMO and CMSAF are deprecated.				Weather and radiation data: NSRDB PSM V3 typical meteorological year datasets (tmy-2020 and the Himawari TMY) replace the older 2015 NSRDB sets.
Licence and cost model: Public web service with no stated fee on the API page. Only GET requests are accepted and the rate limit is 30 calls per second per IP address.	Licence and cost model: Paid annual subscription. A 30-day evaluation exists, with generic components and an EVALUATION label on reports, according to a third-party review.	Licence and cost model: Commercial product of Aurora Solar. A review site lists no public pricing.	Licence and cost model: Free and open source under the BSD 3-Clause licence, with source code on GitHub.	Licence and cost model: The page states the model may be used for any purpose, and that NREL gives no support, consulting or training.
Platform and integration: Web API for scripts and applications. AJAX calls are blocked by the CORS policy, so browser pages need a server-side proxy.	Platform and integration: Windows workstation software that cannot run through a Windows Remote Desktop client. A separate command-line product exists for server runs.	Platform and integration: Web-native platform.	Platform and integration: Desktop application written in C++ with wxWidgets.	Platform and integration: Web calculator with an API now at version 8.
Version and status: PVGIS 5.3 and 5.2 are served at versioned API paths. The unversioned path serves 5.2 for a limited period, and access to 5.1 has been removed.	Version and status: PVsyst 8 is the current professional release listed on the vendor shop.	Version and status: Aurora Solar announced the acquisition of developer Folsom Labs in August 2021 and presents HelioScope as part of its offer.		Version and status: Current version 8.4.0, released on 5 September 2024.