An Integrated Energy Storage Scheme for a Dispatchable Solar and Wind Powered Energy System and Analysis of Dynamic Parameters

The intermittency of wind and solar power and the mismatch between when they are available and when demand is high have hindered the expansion of these two primary renewable resources. The goal of this research is to analyze an integrated energy system (named DSWiSS for dispatchable solar wind storage system) that includes a novel configuration of wind and solar together with compressed air energy storage (CAES) that is driven from excess nighttime wind energy and thermal storage energized by concentrated solar power in order to make these sources dispatchable during peak demand. Notably, existing CAES facilities use natural gas for heating the compressed air before its expansion through a turbine; the system described in this paper replaces the use of natural gas with solar energy and thermal storage, thereby obviating the need for fossil fuels and yielding a dispatchable system powered completely by renewable sources. This paper builds off prior published work for the DSWiSS configuration with an analysis of temporally-resolved parameters, including wind and solar resources, which are important to the operation of DSWiSS. This analysis uses actual historical meteorological data for West Texas solar insolation, telemetry data for wind power in West Texas, and recorded electricity demand data of the ERCOT grid to assess system performance. We examined how the daily variation of these parameters could affect the operation of an energy storage facility such as DSWiSS. We found that the daily fluctuations were most pronounced in the summer when demand is highest and wind velocity is lowest. However, because all seasons show a time-of-day phase mismatch between demand and wind velocity, we expect that a load leveling energy storage technology would be useful to the electric grid. Research to be completed soon will attempt to use control strategies along with the existing thermodynamic model of the DSWiSS power system to determine how DSWiSS would be operated differently under the different seasonal situations.