GHI and DNI uncertainty data

GHI and DNI model uncertainty

Uncertainty estimates are available to Full evaluation projects only and are part of the Full evaluation project package at no additional cost.

Uncertainty estimates are not displayed by default - you need to activate them through the Project data add-ons.

Note: The Uncertainty estimates may take up to several hours from the time of request to show in the Analysis section.

Uncertainty estimates in Evaluate

We provide uncertainty estimates separately for GHI and DNI on the dedicated pages. These pages present a comprehensive uncertainty framework for solar resource assessment. The pages offer the data in a structured format as follows:

• Model uncertainty: Shows the inherent uncertainty in the modeling methods used to estimate long-term irradiation values. GHI models demonstrate lower uncertainty than DNI models, which is expected as GHI is typically more stable and easier to model than DNI.

• Uncertainty due to Interannual variability: Quantifies how much solar resource values naturally fluctuate year-to-year due to weather patterns. This variation decreases significantly as the averaging period extends from 1 to 30 years.

• Combined uncertainty of LTA at 90% probability of exceedance: This combines both uncertainty sources to provide overall confidence levels, critical for financial modeling.

• Minimum expected LTA values at different Pxx: This table presents the minimum irradiation values (kWh/m²) expected at different probability thresholds across various time periods (1, 20, 25, and 30 years), allowing stakeholders to select appropriate risk levels for project planning.

Note: We have highlighted widely-used industry standard values in the table for your convenience.