Solar resource information is used in a variety of ways to evaluate the impacts of the high penetration of solar technologies on the electrical grid envisioned by the DOE SunShot Initiative. Variations in the sun and in the weather cause seasonal, daily, and short-term fluctuations in the output of solar systems. Therefore, understanding the available solar resource helps to predict how solar systems—both photovoltaic (PV) and concentrating solar power (CSP) technologies—react to fluctuations and interact with the electric grid.
Both historical and forecasted solar resource data are valuable for supporting power system planning and operations. A major challenge of solar resource assessment is to refine techniques to forecast solar resources in hourly or sub-hourly intervals at least one to three days in advance. When linked to power output assessments by large system arrays, these forecasts support both day-ahead and real-time power system operations.
Solar resource production data is vital in determining the best locations for installing high penetrations of solar on the electric grid.
Output from PV power plants is dependent on the amount of solar energy reaching the earth’s surface. Variability in solar radiation results in variability in PV plant output. The combined influence of the atmospheric constituents and their separate variability characteristics makes solar variability modeling a complicated task.
It is important that power system operators understand and accurately forecast variations in solar irradiance. Inaccurate forecasts could result in the system operator making sub-optimal decisions, potentially leading to higher integration costs for solar plants and/or curtailment of solar generation.