Methods of Freeze Protection for Fruit Trees by Means of Renewable Energy Sources R. A. Kasymbekov, N. Y. Temirbaeva, S. O. Nazarov, Y. Zh. Osmonov and Nurzhan Murat E3S Web Conf., 288 (2021) 01001 Published online: 14 July 2021 DOI: 10.1051/e3sconf/202128801001