Energetic and economic evaluation of hybrid solar energy systems in a residential net-zero energy building

Abstract

Net-zero energy buildings are playing a critical role in the decarbonization of future cities since the buildings are responsible for 30–40% of total energy consumption. A residential net-zero energy building with a prospect of commercialization was introduced, which adopts solar energy systems and heat insulation solar glass that simultaneously generates electric power and minimizes heat loss. Dynamic and parametric simulation models were developed based on the TRNSYS platform and were validated by experimental data or standard test reports. A multi-criteria decision-making framework based on the energetic and economic criteria was developed to evaluate system performance and to find the favorable layout of the energy system in the residential net-zero energy building. Twelve system scenarios, covering the individual heat insulation solar glass system, the hybrid systems integrated with solar PV, solar thermal and heat insulation solar glass, and the hybrid systems combined solar thermal and heat insulation solar glass, were comparatively assessed. Among the system scenarios inclusive of solar thermal technology, a combination of the compound parabolic concentrated solar collector and variable-effect absorption chiller is highly recommended. However, the system scenario, which consists of a specific PV area of 8.4 m2/kW and employs heat insulation solar glass, is most favorable due to a highest primary energy saving ratio of 1.05 and a lowest levelized total cost of 5920 US$/year. All system scenarios proposed herein are not economically feasible at the current economic parameters in Singapore’s climate. However, the optimized hybrid system (integrated with solar PV, solar thermal and heat insulation solar glass) is sufficient to reach the net-zero energy target while the optimized solar PV system combined heat insulation solar glass is a solution of the positive energy building.