Solar Resource Compass

Core Features

Solar Resource Compass is primarily an early-stage resource and energy-yield assessment tool. DNV developed it to make analysis similar to that used by its independent engineering teams available through an automated online platform.

• Solar Irradiance Comparison: SRC compares solar-resource estimates from different sources including Solcast, Solargis, PVGIS and NREL, depending on location. Tables, plots and maps make differences between datasets easier to identify.

• Weather Data Analysis: Users can examine statistics for Global Horizontal Irradiance (GHI), Direct Horizontal Irradiance (DHI), temperature and wind speed, including averages, medians and standard deviations. They can also upload their own or purchased third-party weather data for comparison.

• Soiling and Snow Loss Estimates: The platform estimates how accumulated dust and snow could reduce a project's electricity production. These losses can vary significantly by location and therefore affect expected project performance.

• Ground Albedo Data: SRC provides information on albedo—the proportion of sunlight reflected from the ground. This is particularly important for bifacial solar panels, which can generate electricity from light reaching both sides of the module.

• Indicative Energy-Yield Assessment: Using modelling technology from SolarFarmer and weather data from Solcast, SRC can rapidly estimate the electricity a proposed PV project could produce, allowing developers to screen projects and assumptions before commissioning more detailed assessments.

• Data Export and API Access: Users can download TMY/TGY weather files compatible with software including PVsyst and SolarFarmer. Higher-level access includes APIs for integrating SRC calculations into internal analysis, dashboards and automated project-development workflows.

Closing Insights

DNV launched Solar Resource Compass in the United States in February 2020, initially concentrating on comparing irradiance datasets and estimating snow and soiling losses. The underlying problem is consequential: DNV has reported that estimates from different irradiance sources can diverge by more than 10% at some locations. Since expected electricity production feeds directly into project valuations and financing assumptions, choosing an unsuitable dataset can result in a solar project being materially over- or undervalued.

SRC has subsequently developed from a North American resource-comparison tool into a broader solar assessment platform. DNV launched it in Europe in June 2024, by which point customers had evaluated more than 10,000 projects in the United States through the platform. The European expansion also demonstrated greater integration within DNV's software portfolio: Solcast supplies high-resolution weather data while SolarFarmer provides the underlying energy-modelling capabilities used for indicative production estimates.

For prospective users, the distinction between SRC and SolarFarmer is useful. SRC primarily helps answer “How good is the solar resource here, which data should I trust, and roughly how might the project perform?” SolarFarmer goes deeper into the actual engineering of a utility-scale PV plant, including layout, equipment, terrain, shading and detailed energy-yield modelling. The two can therefore support different stages and depths of solar project assessment.