Evaluating Urban WRF-Solar for Photovoltaic Power Forecasts in New York City

Recent developments in the Weather Research and Forecasting (WRF) Model have made it possible to accurately estimate incident solar radiation. This study couples the WRF-Solar module with a multi-layer urban canopy and building energy model in New York City (NYC) to create a unified WRF forecasting model. Hourly forecasts are validated against ground station data collected at eight different sites. Validation is carried out independently for clear and cloudy sky conditions. Results indicate that the uWRF-Solar model can forecast solar irradiance considerably well for the global horizontal irradiance (GHI) with an R squared value of 0.93 for clear sky conditions and 0.76 for cloudy sky conditions. Results are further used to directly forecast solar power production in the NYC region, where evaluations of generation potential are done at the city scale. Outputs show a gradient of power generation produced by the potential available solar energy on the entire uWRF-Solar grid. In total, for the month of July 2016, NYC had a city PV potential of 233 kW/day/m2 and 7.25 MWh/month/m2