Government sponsored tools
- mapserve3.nrel.gov/PVWatts_Viewer/index.html: PVWatts "Performance calculator for grid-connected PV systems" interactive map for the US - very nice!
- rredc.nrel.gov/solar/calculators/PVWATTS/version1: PVWatts for US and worldwide
- https://openpv.nrel.gov: Open PV Project Database
- re.jrc.ec.europa.eu/pvgis: PVGIS "Photovoltaic geographical information system"
- http://www.retscreen.net/ang/home.php: Retscreen - Natural Resources Canada
