As solar becomes a more attractive investment, transaction speed often takes precedence over accuracy, which can lead to market inefficiencies. In the 2021 Solar Generation Index report, kWh Analytics is supplying transparency to the solar industry with a performance analysis of a significant segment of the U.S. solar asset class. The goal: develop an index to track the magnitude of the industry’s accuracy—or inaccuracy—when determining a solar project’s “most likely production” P50 estimate.
The results of the 2021 Solar Generation Index are clear: Overall, the solar PV assets in this study tended to underperform their P50 estimates, and the performance gap is widening over time. According to kWh, this trend “illustrates that P50 estimates can still be subjectively developed, even with better modeling.”
With the solar industry’s continued growth dependent on the ability to deliver promised returns to investors, understanding trends such as these is critical to reducing risk on future projects. The 2021 Solar Generation Index reinforces the need for the solar industry to come together to improve accuracy and increase objectivity in P50 analyses.
2021 Solar Generation Index reference weather dataset: SolarAnywhere®
The performance of operating utility-scale projects from 15 of the 20 largest solar asset owners in the U.S. was analyzed for the 2021 Solar Generation Index report. For the second year in a row, kWh Analytics selected SolarAnywhere solar resource data as the reference weather dataset. There are many reasons kWh Analytics relies on bankable SolarAnywhere Data for the Solar Generation Index analysis, including objectivity of P50 estimates for primary assessment, and data consistency for ongoing valuation.
SolarAnywhere resource data is benchmarked against 926-site years of independent ground measurements of the highest-available quality, such as those maintained by the World Radiation Monitoring Center Baseline Surface Radiation Network (BSRN). This model validation is kept up to date so that users may have confidence in the accuracy—and the low bias—in their solar resource data. For the key step of performance benchmarking in kWh Analytics’ Solar Generation Index report, SolarAnywhere offers complete time-series data (through real time) accessible via the web and API.
Read the full kWh Analytics’ 2021 Solar Generation Index to dive deeper into the research results and recommendations for the solar industry.