GrünstromIndex vs UK Carbon Intensity

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.

This is the official carbon intensity forecast and outturn API for Great Britain's electricity grid, published by National Grid ESO, giving live and forecast gCO2/kWh figures nationally and regionally. It's a fully open government data feed with no key required.