A combined experimental and modelling investigation of an overground compressed-air energy storage system with a reversible liquid-piston gas compressor/expander

We consider a small-scale overground compressed-air energy storage (CAES) system intended for use in micro-grid power networks. This work goes beyond previous efforts the literature by developing and showing results from first-of-a-kind (20 kWh) near-isothermal CAES employing novel, reversible liquid-piston gas compressor expander (LPGC/E). Additionally, we extend our study to assessments, first time, of economic environmental characteristics these systems through combination experimental, thermodynamic, technoeconomic analyses. Five configurations are considered: (1) CAESbase, which is base-case system; (2) CAESplate, parallel plates inserted into LPGC/E as heat exchanger achieving compression expansion; (3) CAESPCM, phase change material (PCM) employed store thermal compressed air during charging that later recovered discharge; (4) CAESPCM&plate, CAESplate CAESPCM arrangements; (5) CAESheater, heater utilised instead PCM preheat discharge. Data validation computational design tool based on assessments were performed obtained prototype CAESbase system. Results show CAESPCM&plate exhibits highest roundtrip efficiency 63% shortest payback period 7 years; latter with inclusion governmental incentives an electricity smart export guarantee (SEG) support rate 5.5 p/kWh (6.8 ¢/kWh). The found be cost-effective even without incentives, 10 years. also associated 71 tonnes fuel consumption savings reduced CO2 emissions amounting 51 over lifetime 20