Abstract
The article presents an evaluation of the performance of a ground-source heat pump system designed to maintain a specific temperature regime within a biogas bioreactor. The novelty and distinctive feature of the installation lie in its use of renewable thermal energy sources. For the first time, a system with an external ground-source heat pump circuit consisting of four boreholes with copper U-shaped tubes through which the coolant circulates has been developed. The system's design, operating principle, and technical specifications are described. An assessment of the thermal energy output, accounting for the efficiency characteristic of the external circuit of a ground-source heat pump is shown.