The subject of the work concerns the design of a hybrid solar system to maintain mesophilic conditions in the process of anaerobic biomass decomposition. The main purpose of the work was to design a hybrid heating installation for a biomass utilizer. It was assumed to simulate the use of three energy sources: photovoltaic panels, solar collector and heat from biogas combustion. It was assumed that the results of the analysis will be supported by evaluation of biogas yield for waste consisting food. The quasi-continuous and periodic operation of the rendering chamber was tested in relation to the energy demand for maintaining the mesophilic conditions in the fermentation process. As a result of the objective of the work, biogas productivity tests of the selected substrate mixture were carried out. A general design of the utilization plant (microbiogas plant) was also carried out, including thermal insulation and the design of the heating system. In order to determine the heat losses of the digester, the methodology based on the heat transfer coefficient by individual partitions was used. The level of biogas production was determined using a test stand complying with the requirements of DIN 38 414 S.8. On the basis of the volume of biogas production, thermal deficiencies resulting from its combustion were determined. Biogas deficiencies constituted more than 30% in the worst computing conditions for the periodic system and about 6% for the quasicontinuous system. The designed heating installation, which uses additional solar energy, in the case of a periodic system, allowed to cover 100% of the summer heat demand. In winter, the coverage of heat demand was around 90% for average monthly temperatures in December and January and 80% for the worst computing conditions. Identified energy shortages can be limited by optimizing the control of the biological process and optimizing the parameters of thermally insulating layers.