# Free Energy and Environment Data APIs

Page: https://free-web-services.com/web-services/open-data/energy/

Energy and environment APIs give electricity generation, prices and carbon intensity, energy statistics, flood warnings and river and water measurements. Use them to show when power is greenest, warn about floods or follow energy prices.

## Services

| Service | API key | Formats | Free use |
|---|---|---|---|
| [Carbon Intensity API (GB)](https://free-web-services.com/web-services/open-data/energy/carbon-intensity-api-gb.md) | Not needed | JSON | Free, no key needed. |
| [EIA Open Data API](https://free-web-services.com/web-services/open-data/energy/eia-open-data-api.md) | Needed, free | JSON | Free with a free API key. |
| [Energy-Charts API](https://free-web-services.com/web-services/open-data/energy/energy-charts-api.md) | Not needed | JSON | Free, no key needed. |
| [Flood Monitoring API (Environment Agency)](https://free-web-services.com/web-services/open-data/energy/flood-monitoring-api.md) | Not needed | JSON | Free, no key needed. |
| [USGS Water Data API](https://free-web-services.com/web-services/open-data/energy/usgs-water-data-api.md) | Not needed | JSON | Free, no key needed; a free api.data.gov key raises the rate limit. |

## Questions

**Which free energy and environment data APIs work without an API key?**  
Carbon Intensity API (GB), Energy-Charts API, Flood Monitoring API (Environment Agency) and USGS Water Data API work without a key, according to their documentation. Most keyless services ask you to keep the number of requests reasonable, and some ask for a User-Agent that names your app.

**Are these energy and environment data APIs really free?**  
The services here can be used without paying, at least on a free plan or free tier, often with limits such as a number of requests per day or non-commercial use only. The table above quotes what each service says about its free use; check the provider's own terms before you rely on it.

**How up to date is this list?**  
The address of every service is checked about once a week, and services that stop working or stop being free are removed. This list last changed on November 8th, 2026.