Development of a Ground-based, High-fidelity Solar Observatory

In recent years, California has committed to increasing its renewable energy portfolio, particularly through the use of PhotoVoltaic (PV) power generation. Increased levels of PV penetration into the electric grid requires accurate forecasting on multiple time horizons to counteract the intermittent nature of the solar resource.  The development of these solar forecasting models benefits from the collection of high quality irradiance data. To this end, our team designed and tested a solar observatory at the University of California San Diego Calit2 building, which provides high fidelity solar irradiance measurements at intra-minute sampling rates. Instrumentation at the observatory includes several radiometers for the measurement of Direct Normal Irradiance (DNI), Global Horizontal Irradiance (GHI) Diffuse Horizontal Irradiance (DHI) and Infrared Irradiance (IR). Data is streamed in real time to a centralized database and used as an input to several models which forecast the solar resource on multiple time horizons. To ensure accuracy, the data is compared against the Coimbra Group’s pre-existing solar observatory also located at the University of California, San Diego.