Integration of compressed air energy storage with wind generation into the electricity grid

Integration of renewable electricity from wind farms into the electricity grid presents challenges because wind is a highly variable resource whereby the amount of power generated depends on local wind speed, air density and wind turbine characteristics. Energy storage is one possible approach to mitigate power fluctuations and quality issues. Among presently available technologies to store energy, Compressed Air Energy Storage (CAES) shows many attractive features. This work focuses on techno-economic modelling and analysis for the integration of wind turbines with CAES into the power grid. To have a deep understanding of the performance, characteristics and benefits of system integration, technical and economic models for CAES processes are developed in the processes simulation software ECLIPSE. To conduct this study, two scenarios that are each dependent on generation scales and locations were proposed; (1) centralised CAES (based on the diabatic method) (2) distributed CAES (based on the adiabatic approach). The nominal power generation of centralised and distributed CAES systems were given as 280 MWe and 5 MWe, respectively. The impact of CAES systems on the electricity market is also discussed. Techno-economic analysis of the modelled centralised CAES system showed round-trip efficiency of around 53.6% (and around 56.7% for the modelled distributed CAES system). Specific investment was found to be around €585/kWe (€2452/kWe) and break-even electricity selling price to be around €111/MWh (€275/MWh). Their CO₂ emissions were found to be compatible with the average CO₂ emissions of UK CCGT power generation.