Performance comparison of photovoltaic thermal-assisted heat pump and conventional water heating systems in Turkey: a thermo-electrical and environmental assessment

Abstract

Photovoltaic thermal (PVT) collectors are more advantageous than traditional solar systems because they reduce the high electricity costs associated with hot water systems and simultaneously produce both thermal and electrical energy. Furthermore, integrating a water-source heat pump can increase thermal and electrical energy efficiencies. In this paper, the thermal performance of three different water heating systems is examined across different climate regions in Turkey (Ankara, Izmir, Trabzon, and Hakkari) using comparative analyses of one-year data with the Transient System Simulation Tool program. The investigated systems are as follows: (i) traditional domestic electrical water heating (EDHW) system, (ii) PVT-assisted domestic water heating (PVT-DHW) system, and (iii) PVT-assisted domestic water heating system integrated with a heat pump (PVT-HPDHW). The highest annual total PVT efficiency was achieved in Izmir, with 66% in the PVT-DHW system and 73% in the PVT-HPDHW system. On the other hand, the lowest annual cost was $69 for the PVT-DHW system in Izmir and $36 for the PVT-HPDHW system in Hakkari. The results showed that the innovative PVT-HPDHW system achieved the highest overall energy efficiency, the lowest grid dependency, and the lowest CO2 emissions. Compared with the conventional EDHW baseline, this integrated configuration reduced annual grid electricity consumption by up to 78% and mitigated annual CO2 emissions by up to 93%. Among the systems considered, it also provided the highest thermal and electrical energy yield from the PVT collectors. In addition, the lowest annual CO2 emissions were observed in Izmir for the PVT-DHW system and in Hakkari for the PVT-HPDHW system.