Renewable Generation Forecasting: The Science, Applications, and Outlook

While still a small fraction of the electric energy supply portfolio in the United States, renewable electric generation -- mostly wind and solar photovoltaic (PV) surpassed 55 GW of installed capacity at the end of 2011. This capacity is not evenly distributed, and has reached levels of operational importance in many utility balancing areas. Earlier research has shown that the ability to forecast production from these resources over important operational time horizons -- from an hour to a day ahead -- is a key for minimizing integration impacts. In this paper, the current state of renewable generation forecasting is described, along with the scientific challenges, existing and emerging applications, and prospects for the future.