Comparison of performance parameters of a building heating system including heat pump and underground energy storage tank assisted with and without solar energy

Underground storage tanks are used to efficiently store thermal energy for domestic and commercial heating systems. This study compares two systems; The first consists of an underground storage tank, a heat pump, and a building to be heated. The second system consists of the same components with adding solar collectors (SC). An analytical model of each system is developed to find the performance parameters of the heating systems. The Coefficient of Performance (COP), the temperature of water in the storage tank, and useful solar energy are part of the main performance parameters. A MATLAB program based on the analytical model is prepared for computing all performance parameters of the heating systems. In the fifth year of operation, the results showed adding the SC led to increasing the temperature of water in the tank by at least 10.2 ℃; it also showed an increase in the value of COP around 1.8. These results were obtained for a tank volume of 400 m3 , a Carnot efficiency of 40%, and a house in Gaziantep.