Sizing and operation of energy storage by Power-to-Gas and Underwater Compressed Air systems applied to offshore wind power generationElena Crespi, Luca Mammoliti, Paolo Colbertaldo, Paolo Silva and Giulio GuandaliniE3S Web Conf., 312 (2021) 01007DOI: https://doi.org/10.1051/e3sconf/202131201007