Public-Private Collaboration to Improve Wind Ramp Forecasts

For the renewable wind energy industry, wind ramp events are large, sometimes unexpected changes in wind speed over short time periods which can dramatically alter forecast power generation. Wind ramp events are inherently difficult to forecast accurately and can be caused by different phenomena including movement of air masses; development or movement of large-scale weather systems; thunderstorms; and various boundary layer processes, including vertical mixing and diurnal heating. Weather forecast errors in the timing and amplitude of wind ramp events present challenges to the energy sector. Electric grid operators must instantaneously and continuously balance energy supply and demand. Insufficient wind ramp forecasts and the resulting variability in generated power make it difficult for industry to take advantage of the wind energy produced, minimize energy costs to users, reduce energy reserves and the greenhouse gases emitted by these reserves.

To address these challenges, the Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy is partnering with the National Oceanic and Atmospheric Administration (NOAA) and the wind energy enterprise in a field project to improve forecasts of turbine level wind speeds and the identification of wind ramp events. The objective of the field project is to demonstrate that wind forecasts and ramp identification can be improved with better observations, and that the private sector can use these improved wind forecasts to create more accurate predictions of power generation. This field project will begin in early CY2011, last for one year, and has four main components: 1) assimilation of both public and proprietary private sector observations to better characterize the boundary layer and improve model initialization, 2) use of NOAA's new High Resolution Rapid Refresh (HRRR) model to provide wind forecasts, 3) analysis of the impact of the assimilation of the new observations into the HRRR model on the skill of wind forecasts, especially ramp events, and 4) analysis of the improved model forecasts on the efficiency and economics of wind power generation.

NOAA will use the HRRR weather model, which is currently run at 3-km horizontal resolution over the CONUS in a research mode by NOAA's Earth System Research Laboratory. The private sector participant(s) will use HRRR output to create wind and power forecast products tailored for the wind energy industry. DOE, NOAA, and the wind energy enterprise will participate in verification of the improved models and forecasts. One output of the field project will be an assessment of the types of sensors, their siting and deployment density to adequately sense the atmosphere, and especially the boundary layer, to improve wind forecasts.