Methodological aspects of evaluating the effectiveness of using local energy systems with renewable sourcesSergij Dudnikov, Oleksandr Miroshnyk, Stepan Kovalyshyn, Vadym Ptashnyk and Krzysztof MudrykE3S Web Conf., 154 (2020) 07013DOI: https://doi.org/10.1051/e3sconf/202015407013