Temporal resolution data types

  • Published on Apr 14, 2025
  • 5 minute(s) read
  • MK

In this document

We will present 1-minute, 15-minute, and 60-minute datasets, their purpose, advantages, disadvantages, and typical use cases to help you make better decisions when designing solar projects using the Solargis platform.

Temporal resolution impact on data representation

The temporal resolution of solar data significantly affects how accurately it reflects the variability of solar irradiance and weather conditions. Historically, 60-minute data was the industry standard due to technological and computational limitations in data collection and processing systems. As the solar industry matured, the need for higher-resolution data became apparent, leading to the development of 15-minute and eventually 5-minute datasets.

The evolution toward higher temporal resolution has been driven by the recognition that solar irradiance can change dramatically within short timeframes. 60-minute data averages out these fluctuations, presenting a smoothed profile that masks significant variability. This averaging effect can lead to underestimation of production losses during partly cloudy conditions and misrepresentation of system performance.

15-minute data emerged as the new standard, capturing more of the natural variability while remaining manageable in terms of data volume. This resolution reveals intra-hour patterns and provides a more realistic representation of cloud-induced irradiance changes, though it still averages out some of the most rapid fluctuations.

1-minute data represents the highest standard for detailed analysis, capturing rapid irradiance changes due to passing clouds that lower-resolution data completely smooths out (fig.1). This difference is particularly evident when comparing the representation of clear-sky exceedance events (when irradiance exceeds clear-sky values due to cloud enhancement), which are only visible in high-resolution data.

Visual representation differences:

  • 60-minute data shows averaged values, masking short-term variability and underestimating the impact of intermittency.

  • 15-minute data reveals more detailed patterns of irradiance changes, capturing some cloud movements and system response characteristics.

  • 1-minute data captures rapid fluctuations, including cloud enhancement effects and short-duration shading events.

Fig.1: Comparison of hourly averaged and 5-minute (top) GHI Time Series data (source).

Usage in the PV projects

Despite their differences and limitations, each temporal resolution dataset serves a valuable purpose in today's solar industry. Rather than viewing these datasets as competing alternatives, industry professionals recognize them as complementary tools within a comprehensive solar resource assessment toolkit.

The choice of temporal resolution should align with specific project requirements, development stage, and analytical objectives. Early-stage feasibility studies may only require hourly data, while detailed system design and grid integration analyses benefit from higher-resolution data. Cost considerations, data storage capabilities, and processing requirements also influence the selection of appropriate temporal resolution for each application. By understanding the strengths and limitations of each dataset, solar professionals can select the most suitable resolution for their specific needs.

Hourly data has been the industry standard since the early stages of the solar data industry, when data collection and processing systems were primarily designed for this temporal resolution.

Applications

  • Preliminary energy yield assessments.

  • Initial site prospecting and feasibility studies.

  • Regional solar resource mapping.

  • Typical Meteorological Year (TMY) creation for standard simulations.

Advantages

  • Smaller data volume, easier to process and store.

  • Sufficient for many preliminary analyses.

  • Widely compatible with legacy PV simulation tools.

Limitations

  • Insuficient accuracy and precision for detailed analysis.

  • Masks short-term variability in solar irradiance.

  • Can not capture rapid fluctuations that affect grid stability.

  • Underestimates clipping losses in inverter-limited systems.

  • Insufficient for analyzing ramp rates and short-term grid impacts.

The 15-minute temporal resolution provides a middle ground between hourly averages and high-frequency data, capturing more variability while maintaining manageable data volumes.

Applications

  • Detailed PV system design and optimization.

  • Grid integration studies requiring sub-hourly analysis.

  • Identification of inverter clipping losses.

Advantages

  • Higher accuracy and precision than hourly data.

  • Better representation of solar resource variability.

  • Improved energy yield predictions.

  • Captures more realistic system behavior.

Limitations

  • Still misses some rapid fluctuations visible in higher-resolution data.

  • Requires more storage and processing capabilities than hourly data.

  • May not fully capture all cloud enhancement events.

The highest commonly available resolution for solar resource assessment, 5-minute data provides detailed information on short-term fluctuations in solar irradiance.

Applications

  • Analysis of high-frequency effects on PV system performance.

  • Grid stability and ramp rate studies.

  • Accurate modeling of storage systems and hybrid installations.

  • Detailed assessment of inverter clipping losses.

  • Real-time monitoring and forecasting applications.

Advantages

  • Provides the most accurate and precise information on solar variability.

  • Captures rapid changes in irradiance due to cloud movement.

  • Reveals clear-sky exceedance events not visible in lower-resolution data.

  • Enables more accurate PV output modeling for grid integration.

  • Better represents actual field conditions for performance assessment.

Limitations

  • Larger data volumes requiring more storage and processing power.

  • Requires specialized analysis tools and expertise.

  • Not always necessary for general feasibility studies.

Scientific evidence and industry applications

Research has demonstrated significant differences in the accuracy of PV performance modeling when using different temporal resolutions.

The Solargis study compares solar resource variability using different temporal resolutions of data, including 1-minute ground measurements and 10-minute, 15-minute, and hourly satellite-based model data.

While 1-minute ground measurements showed significantly higher variability than longer time-step satellite data, the variability of utility-scale PV power plant output is lower due to spatial averaging effects. Analysis indicates that 15-minute satellite-based model data can serve as a practical proxy for assessing the variability of typical large-scale PV power plant output, as it closely matches the variability observed when averaging multiple ground measurement points over an area comparable to a utility-scale PV installation.

Fig.2: Comparison of time series data (Solargis satellite model-based data, and ground-measured data from ESMAP) with different time resolutions.

Our approach to temporal resolution

At Solargis, we have developed comprehensive capabilities to provide solar resource data at multiple temporal resolutions to meet diverse industry needs.

Data processing methodology

We employ advanced solar radiation models that leverage satellite observations and atmospheric data to provide accurate solar resource assessments. We have developed proprietary models that:

  • Simulate the interaction between solar radiation and the Earth's atmosphere.

  • Integrate atmospheric data to calculate important inputs for solar models.

  • Improve geographical and time representation of data.

  • Use machine learning algorithms to enhance model accuracy.

Data availability and accessibility

The Solargis database offers:

  • Up to 31 years of historical data.

  • Spatial resolution of up to 90 meters.

  • Standard temporal resolution of 15-minutes, with up to 1-minute with our synthetic data generator.

  • Access through interactive apps, API, and push delivery (SFTP).

  • Support for time series, typical meteorological year (TMY), and long-term average (LTA) data.

Application in real-world projects

At Solargis, we provide high-resolution, granular solar resource and meteorological data to PV project stakeholders. Our high-resolution data enables:

  • Accurate solar resource and PV yield assessments in the design phase.

  • Improved generation forecasting.

  • Enhanced project monitoring.

  • More accurate performance assessment.

  • Verification of on-site measurements.

  • Better management of weather-related risks.

Conclusion

The choice of temporal resolution depends on your specific project needs. For initial feasibility studies, 60-minute data often suffices. When designing PV systems or conducting detailed yield assessments, 15-minute data is a good compromise between accuracy and complexity.. For detailed grid integration studies, hybrid powerplant design, or analyses of rapid fluctuations, 15-minute data delivers the necessary detail.

Consider your project stage, analytical requirements, and processing capabilities when selecting the appropriate resolution. Solargis offers all these options, allowing you to match data granularity to your evolving project needs from development through operation.

Further reading