The solar resource assessment activities are conducted within the Solar Energy Technologies Program (Solar Program) in the Systems Integration subprogram. The activities focus on solar resource forecasting, characterization, and data gathering and are conducted through the national laboratories and industry partnerships.
Solar resource information is used to estimate the amount of solar electricity or thermal energy that can be generated in a given area. It is natural for variations in the sun and in the weather to cause seasonal, daily, and short-term fluctuations in the supply of solar resources. 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.
Comprehensive information on the temporal (time) and spatial (location) characteristics of the solar resource and related weather data is also used to simulate how solar systems will perform. Both historical and forecasted solar resource data are valuable for power system planning and operations. One of the challenges of solar resource assessment is to refine techniques to forecast solar resources in hourly or subhourly intervals at least one to three days in advance, to support both day-ahead and real-time power system operations.
Power companies, such as utilities that must meet renewable portfolio standards, can use accurate short-term and day-ahead forecasting to help operators determine and optimize the power generation mix needed to meet the daily demands of their consumers. With high penetration of variable renewable energy, long-term solar resource assessment data are required to support generation resource planning.
The Systems Integration subprogram focuses on these three solar resource assessment activities: