Small scale Compressed Air Energy Storage application for renewable energy integration in a listed building

In EU where the architectural heritage is significant, enhancing the energy performance of historical buildings is of great interest. Constraints, such as the lack of space especially within the historical centers and architectural peculiarities, make the application of technologies for renewable energy production and storage a challenging issue. This study presents a prototype system consisting in using the renewable energy from a Photovoltaics (PV) array to compress air for a later expansion to produce electricity when needed. The PV-integrated small scale Compressed Air Energy Storage system is designed to address the architectural constraints. It is located at the unoccupied basement of the building. An energy analysis was carried out for assessing the performance of the proposed system. The novelty of this study is to introduce experimental data of a CAES prototype suitable for dwelling application as well as its integration accounting for architectural constraints. The simulation, carried out for a summer average day, shows that the compression phase absorbs 32 % of PV energy excess in a vessel of 1.7 m3 and the expansion phase covers 21.9 % of the dwelling energy demand. The electrical efficiency of a daily cycle is equal to 11.6 %. If air is compressed at 225 bar, instead of 30 bar, 96.0 % of PV energy excess is stored in a volume of 0.25 m3, with a production of 1.273 kWh, 26.0 % of the demand.