ECMWF ERA5 reanalysis
ecmwf
Hourly global atmospheric reanalysis from 1940 to the present, the reference weather input for European and global energy system modelling.
Before you use this
- Reanalysis wind speeds are known to be biased low in complex terrain; downscaling is normally required before siting use.
- The 31 km grid does not resolve individual wind farms. A cell value is an area average, not a site measurement.
- ProvenanceUntraced
- DocumentationFully documented
- Currency & maintenanceAging
ERA5 is the fifth-generation ECMWF atmospheric reanalysis of the global climate, produced by the Copernicus Climate Change Service. It assimilates observations into a fixed forecast model to produce a physically consistent hourly record on a roughly 31 km grid. In energy modelling it is the dominant source of wind speed, solar irradiance and temperature time series, which makes it the most common shared upstream origin in the catalog: two datasets that appear independent frequently both derive from it.
- Identifier
https://cds.climate.copernicus.eu/datasets/reanalysis-era5-single-levels- Domains
- Renewable resource & weather
- Keywords
- Copernicus, ERA5, reanalysis, solar, temperature, weather, wind
Fitness for purpose
- Supports
- Capacity Expansion Modeling, Production Cost Modeling, Resource Adequacy, Siting and Land Use
- Not suitable for
- Power Flow Analysis
The exclusions are the half you cannot get anywhere else. A dataset that is wrong for your question is worth knowing about before you build on it.
Structure
- Network topology
- Not captured
- Impedances
- Not captured
- Voltage classes
- Not captured
- Provenance class
- reanalysis
- Upstream sources
- Not capturedWhich is a statement about what the catalog can show, not about how the data was produced.
- Licence
- LicenseRef-Copernicus-1.2
- Redistribution
- Not captured
Access terms, per path
Zarr, consolidated metadata (ARCO-ERA5 on Google Cloud)
none
NetCDF-4 or GRIB, on request
accountRequired · Copernicus CDS account and API key
Zarr v2
none
Geographic
- Bounding box
- Global
- Granularity
- gridded
- Native CRS
- EPSG:4326
- Geometry types
- Not captured
- Features
- Not captured
- As WKT
POLYGON((-180 -90, 180 -90, 180 90, -180 90, -180 -90))
Temporal
- From
- Jan 1, 1940
- To
- Aug 1, 2026
- Update cadence
- daily
- Time resolution
- hourly
| Field | Definition | Type | Unit | Concept | Value basis | Provenance | Report an issue with this field |
|---|---|---|---|---|---|---|---|
roRunoff | Water leaving the surface and sub-surface as runoff, accumulated hourly. Used as a hydro inflow proxy after catchment aggregation. Caveat: Not a reservoir inflow. Using it directly as hydro availability without routing overstates responsiveness. | float32 | mm | Hydro inflowInferred | modeled | Read from: ecmwf-era5 | |
ssrdSurface solar radiation downwards | Shortwave radiation reaching a horizontal surface, accumulated over the hour. Equivalent to global horizontal irradiance once divided by the accumulation period, which is the conversion most consumers forget. Caveat: Accumulated, not instantaneous. A consumer treating the raw value as W/m2 overstates irradiance by a factor of 3600. | float32 | W/m² | Global horizontal irradiance | modeled | Read from: ecmwf-era5 | |
t2m2 metre temperature | Air temperature at two metres above the surface. | float32 | degree Celsius | Air temperature | modeled | Read from: ecmwf-era5 | |
u100100 metre U wind component | Eastward component of the horizontal wind at 100 metres above the surface. Combined with v100 it gives wind speed at approximately modern turbine hub height, which is why ERA5 is usable for wind yield without extrapolation from 10 metres. Caveat: Complete over the full record; no gaps. | float32 | metre per second | Wind speed | modeled | Read from: ecmwf-era5 |
The catalog says why, rather than leaving the cell blank.
Three independent facets
Graded separately and never combined. A dataset can be perfectly current and completely unprovenanced, and one number would hide exactly that.
Provenance
DUntraced
No upstream source is recorded. This is a statement about what the catalog can show, not about how the data was produced: a carefully measured dataset with no recorded lineage grades D, because a user cannot trace it.
Documentation
AFully documented
All 4 attribute field(s) carry a definition and a unit where one applies. Allowed ranges are not assessed: the fields that carry them are deferred (PRD §4.3), so no record in this catalog states one and grading against them would mark every record down for the same absent field.
Currency & maintenance
BAging
Last updated 2026-08-01 against a stated cadence of P1D; it was due by 2026-08-02 and has not been updated since.
Visible without signing in, deliberately: an evaluator comparing catalogs should not have to register first.
- 10Complementary
- 2Related by lineage
- Global Wind AtlasStrength 2 of 5Related by lineage
Directly related by lineage: one of these is built from the other, so agreement between them is not independent evidence.
- · Shares 2 concept(s), including Wind speed.
- · Both feed Siting and Land Use.
- · Coverage overlaps from 2008-01-01 to 2017-12-31.
- · Bounding boxes overlap over 81% of their combined extent.
- · Both are gridded.
- NREL National Solar Radiation DatabaseStrength 2 of 5Complementary
Both feed: Capacity Expansion Modeling, Production Cost Modeling, Resource Adequacy and Siting and Land Use.
- · Shares 3 concept(s), including Global horizontal irradiance.
- · Both feed Capacity Expansion Modeling, Production Cost Modeling, Resource Adequacy and Siting and Land Use.
- · Coverage overlaps from 1998-01-01 to 2024-12-31.
- · Bounding boxes overlap over 19% of their combined extent.
- · Both are gridded.
- Global Energy Monitor Global Integrated Power TrackerStrength 2 of 5Complementary
Both feed: Capacity Expansion Modeling and Production Cost Modeling.
- · Both feed Capacity Expansion Modeling and Production Cost Modeling.
- · Coverage overlaps from 2000-01-01 to 2026-07-01.
- · Bounding boxes overlap over 100% of their combined extent.
- Ember Global Electricity Review and Renewable Target TrackerStrength 2 of 5Complementary
Both feed: Capacity Expansion Modeling.
- · Both feed Capacity Expansion Modeling.
- · Coverage overlaps from 2000-01-01 to 2025-12-31.
- · Bounding boxes overlap over 100% of their combined extent.
- Global Transmission DatabaseStrength 2 of 5Complementary
Both feed: Capacity Expansion Modeling and Production Cost Modeling.
- · Both feed Capacity Expansion Modeling and Production Cost Modeling.
- · Coverage overlaps from 2020-01-01 to 2024-01-01.
- · Bounding boxes overlap over 100% of their combined extent.
- PyPSA-Eur weather cutoutsStrength 2 of 5Related by lineage
Directly related by lineage: one of these is built from the other, so agreement between them is not independent evidence.
- · Shares 3 concept(s), including Wind speed.
- · Both feed Capacity Expansion Modeling and Production Cost Modeling.
- · Coverage overlaps from 2013-01-01 to 2023-12-31.
- · Bounding boxes overlap over 3% of their combined extent.
- · Both are gridded.
- ESA WorldCoverStrength 2 of 5Complementary
Both feed: Siting and Land Use.
- · Both feed Siting and Land Use.
- · Coverage overlaps from 2021-01-01 to 2021-12-31.
- · Bounding boxes overlap over 80% of their combined extent.
- · Both are gridded.
- EIA natural gas prices and Short-Term Energy OutlookStrength 1 of 5Complementary
Both feed: Production Cost Modeling.
- · Both feed Production Cost Modeling.
- · Coverage overlaps from 1997-01-01 to 2026-08-01.
- · Bounding boxes overlap over 9% of their combined extent.
- EIA-930 Hourly Electric Grid MonitorStrength 1 of 5Complementary
Both feed: Production Cost Modeling and Resource Adequacy.
- · Both feed Production Cost Modeling and Resource Adequacy.
- · Coverage overlaps from 2015-07-01 to 2026-08-01.
- · Bounding boxes overlap over 9% of their combined extent.
- PyPSA-Eur grid dataset (pre-built OSM network)Strength 1 of 5Complementary
Both feed: Capacity Expansion Modeling and Production Cost Modeling.
- · Both feed Capacity Expansion Modeling and Production Cost Modeling.
- · Coverage overlaps from 2024-01-01 to 2024-08-01.
- · Bounding boxes overlap over 3% of their combined extent.
- NREL Annual Technology BaselineStrength 1 of 5Complementary
Both feed: Capacity Expansion Modeling.
- · Both feed Capacity Expansion Modeling.
- · Coverage overlaps from 2022-01-01 to 2026-08-01.
- · Bounding boxes overlap over 9% of their combined extent.
- OpenGrid Reference: Cascade InterconnectStrength 1 of 5Complementary
Both feed: Capacity Expansion Modeling and Production Cost Modeling.
- · Both feed Capacity Expansion Modeling and Production Cost Modeling.
OpenGrid redirects you to the source and never proxies the bytes. For a partial read of a large dataset, use the SDK — it fetches an access plan and reads only the slice you asked for.
Zarr, consolidated metadata (ARCO-ERA5 on Google Cloud)
- No account needed:
- Yes
- Supports byte ranges:
- ✓
NetCDF-4 or GRIB, on request
● Checked and working- No account needed:
- No
- Credentials:
- Copernicus CDS account and API key
Zarr v2
● Checked and working- Size:
- 4 TiB
- No account needed:
- Yes
- Supports byte ranges:
- ✓