Environment · head-to-head
Danish data service Energi vs GrünstromIndex
Energi Data Service is the Danish transmission system operator Energinet's open-data platform, publishing dozens of live datasets — day-ahead power prices, grid emissions, consumption, and more — as a free public JSON API with no key required. Its older Elspotprices dataset was retired after the Nordic market's move to 15-minute settlement on 2025-09-30, superseded by the still-live DayAheadPrices dataset.
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.
| Danish data service Energi | GrünstromIndex | |
|---|---|---|
| Authentication | None | None |
| Pricing | free | free |
| Formats | JSON | JSON |
| CORS | no | yes |
| HTTPS | Yes | Yes |
GrünstromIndex supports CORS, while Danish data service Energi doesn't — pick GrünstromIndex for direct browser calls.