The method for Determining the Effectiveness of Low-Grade Geothermal Heat Usage under the Conditions of the Russian ClimateG.P. Vasilyev, N.V. Peskov, V.F. Gornov, M.V. Kolesova and I.A. YurchenkolMATEC Web of Conferences, 30 (2015) 05002DOI: https://doi.org/10.1051/matecconf/20153005002