Performance comparison of two types of technologies associated with a positive energy building: a reversible heat pump/ORC unit and a heat pump coupled with PV panels

To achieve the 20-20-20 targets in 2020 and the European objectives in the longer term, it is imperative to drastically reduce greenhouse gas emissions from the residential building sector. In this context, the development of Positive Energy Buildings (PEB) is promising. This work compares the annual performance of two competing systems. First, a conventional solution, consisting of a passive house coupled with a water to water heat pump and photovoltaic panels (HP/PV). On the other hand, a passive house with a solar thermal roof combined with a reversible heat pump unit / organic Rankine cycle (HP/ORC). Both systems are designed for a maximum net electrical output of 5.29 kW. Dynamic simulations are performed using the Dymola software. The net annual electrical production (considering electricity consumed to fulfil the thermal load of the building) is 667 kWh for the reversible HP/ORC system and 3835 kWh for the HP/PV system in the basic Danish study case. Following that, a study of influence with different climates is performed and some guidelines are deduced to select optimum study cases where the HP/ORC system could become more competitive than the HP/PV classical solution.