Adiabatic compressed air energy storage co-located with wind energy - multifunctional storage commitment optimization for the German market using GOMES
Grid connected energy storage is of particular value mitigating supply uncertainty of intermittent renewable energy resources. For this purpose energy storage can deliver a multitude of services to the electric grid. Application modes limited to only one ore two services often turned out not to cover the initial cost of the storage devices considered. The evaluation of the full value of energy storage taking into account the provision of various services at a time, however, is very challenging. This paper presents GOMESa mixed integer linear programming model for multifunctional commitment optimization of grid connected energy storage devicessuitable for such evaluations. It is applied to an Adiabatic Compressed Air Energy Storage (A-CAES) plant co-located to a wind farm in the northern German region. Besides the minimization of wind energy curtailment of the nearby wind farm, the A-CAES plant is allowed to participate at the day-ahead spot and tertiary reserve market simultaneously. It can be shown that such a multifunctional application mode comprising all of the three services significantly improves the profitability of the A-CAES plant, when compared to application modes comprising only one or two of the mentioned services. GOMES is used to carry out a dimensioning optimization of the multifunctionally applied A-CAES plant, which yields an A-CAES configuration with a considerably oversized compressor and a storage volume of 7 h of full load expander output. Analyzing the resulting operational regime, an elevated number of plant start-ups of approx. two starts per day can be observed. Furthermore, multifunctional application causes a significant increase of part load operation especially at the minimal load point.