Sky Images and Irradiance Measurements from Colorado in 2019

Aggregating sky images and irradiance measurements recorded every 10 seconds during daylight hours for 90 days between September 5th and December 3rd, 2019. It was collected at the National Renewable Energy Laboratory (NREL) Solar Radiation Research Laboratory in Golden, Colorado, using a fisheye webcam and a co-located pyranometer.

Use Cases

• Train short-term solar irradiance forecasting models using sequential sky image data of cloud cover.
• Analyze the relationship between cloud cover patterns in sky images and co-located pyranometer irradiance measurements.
• Apply optical flow methods for linear advection to predict short-term cloud movement from the 10-second interval image sequences.
• Validate very short-term solar forecasting algorithms against a 90-day time series of synchronized image and irradiance data.

Strengths

• Data was recorded at a high temporal resolution of every 10 seconds during daylight hours.
• Provides 90 days of continuous, synchronized sky image and irradiance measurements.
• Collected at a professional research facility (NREL SRRL) with co-located, calibrated instruments.

Limitations

• Data is temporally limited to a single 90-day period in late 2019, which may not represent seasonal or annual variability.
• Geographic coverage is limited to a single location in Golden, Colorado, USA.
• The primary file format is BIN, which may require specific tools or code from the provided repository to process.

Provenance

Source

National Renewable Energy Laboratory (NREL) Solar Radiation Research Laboratory (SRRL).

Collection Method

Collected using an ELP 180-degree fisheye lens USB camera and a co-located LICOR LI200 pyranometer.

Time Range

September 5th to December 3rd, 2019 (90 days).

Freshness

The dataset itself covers 2019, though the metadata was last updated in March 2026.

Geography

Mesa-top campus in Golden, Colorado, USA.