Barriers to energy sustainability: A case study from Ukraine Anatoliy Goncharuk, Veronika Khudolei, Olena Stanislavyk, Vadym Yatsyshyn and Yuliia Semenchuk E3S Web Conf., 307 (2021) 05004 Published online: 22 September 2021 DOI: 10.1051/e3sconf/202130705004