Comparison of PVT - heat pump systems with reference systems for the energy supply of a single-family house

Abstract

Photovoltaic - Thermal (PVT) collectors convert solar radiation into useful heat and electricity simultaneously, and with the same PV area, higher solar energy is harvested; hence PVT can be a key technology for the future supply of buildings. The paper compares different heat supply systems for a single-family house, focusing on PVT and heat pump systems. The results show that the PVT - heat pump achieves a higher seasonal performance factor (SPF) than an air-source heat pump. With 30 m² efficient PVT and the heat pump achieves ≈14% higher SPFbStthan air source heat pump (3.82 for PVT - brine water heat pump to 3.29 air-source heat pump). With the same PVT area, SPFbSt(Grid) including self-consumed PVT electricity by the heat pump system, reaches 4.3 with a demand-based control strategy and 4.97 with a PV-based control strategy. Furthermore, results confirm that by combining PVT collectors and ground-source heat pumps with borehole heat exchangers (BHE), BHEs can be dimensioned 30 to 35% smaller without impacting the system efficiency. The paper also presents the monitoring results of one of the demonstration plants under investigation. The experimental results confirm the good performance of the PVT as a single heat source for heat pumps, with achieved SPFbSt of 3.1 (with 16 m² of the same efficient PVT).

Keywords

• Photovoltaic-Thermal (PVT) collector
• Heat pumps
• Borehole heat exchangers (BHE)
• TRNSYS Simulation
• Monitoring