GrünstromIndex vs Luchtmeetnet

GrünstromIndex (GSI) forecasts, by German postal code, what share of the electricity grid is renewable for the coming hours, so consumers and devices can shift usage toward greener periods. The public front end at gruenstromindex.de is now branded Corrently, and the underlying forecast gateway (api.corrently.io) is HTTPS-only even though the demo site itself still serves over plain HTTP.

Luchtmeetnet is the Dutch national air-quality monitoring network (run by RIVM and partners), publishing measured and forecast pollutant levels from over a hundred stations across the Netherlands. It's a fully open government data feed — no key or registration needed.