Carbon neutrality in the building sector: Optimization of heat pumps operation in combination to PV/T as auxiliary renewable energy system

In recent years, the consequences of climate change have become more than obvious with dramatic impacts to economy as well as society. At the same time energy crisis also significantly affects the living conditions of citizens. In this context, the European Union has decided to follow a transition policy with the ultimate goal of achieving climate neutrality by 2050. An important objective of this transition policy is to reduce the carbon footprint of the building sector, as buildings account for about approximately 40 % of energy consumption and 37 % of CO2 emissions in the EU. To achieve this, a complete cessation of fossil fuel use for heating, cooling, and hot water supply (DHW) is necessary. In this framework, combined with the demand of renewable energy sources (RES) increase for electricity generation, the use of heat pumps is significantly promoted, especially in combination with other RES systems. Decarbonising the electricity grid is a key issue to European Policy for the energy and climate because contributes to the reduction of both operational as well as embodied carbon in buildings. The main goal of this research is to study and optimize the heat pump system use for heating and DHW process, assisted by thermal/photovoltaic systems (PV/T) as auxiliary energy system by forming an objective function and define Key Performance Indicators for the efficient monitoring and evaluation of the system studied. The use of thermal/photovoltaic PV/T panels, simultaneous heating of the water in the system and production of electricity is feasible. The system under study is applied to two typical residential buildings, where the variation between them lies in the different overall heat transfer coefficients. The study is conducted using the TRNSYS (Transient System Simulation) software.