In this work several features of propagation of excitations energy through a water thickness of Lake Baikal are investigated. The conclusions were made by analyzing the temperature series measured in the south basin of the lake. The observations are being carried out near Baikal Neutrino Telescope in the area of Cape Ivanovskii. The energy transfer was examined by a comparative consideration of integral spectral characteristics and spectral characteristics on fixed frequencies. We have compared spectral at various depths and moorings. A velocity of vertical energy transfer during different periods of the year was also estimated.