About 75% of the total energy consumed in non-residential buildings is used for space heating and cooling. For this reason, the need for a sustainable, energy-efficient solution to decarbonise the building sector is high. A promising technology is the combination of a photovoltaic (PV) system, a reversible power-controlled heat pump with electrical and thermal energy storage, controlled by an energy management system (EMS). Latent heat thermal energy storage (TES) for cooling and heating allows thermal energy to be stored in a compact way at stable temperatures with very low losses over time, providing demand-side flexibility for maximum renewable energy via heat pumps. In contrast, a lithium-ion battery (LIB) is an electrochemical energy storage device and the dominant technology used for energy storage systems (ESS), mainly due to its fast response time, efficiency and falling market prices. The integration of both storage technologies enables optimized use of the two forms of energy available in the system. This provides additional flexibility for demand side management to increase the share of renewable energy in the building. The use of renewable energy sources in such a system not only reduces emissions, but also increases self-sufficiency and the use of self-generated PV electricity. These features are important in the context of increasing electrification of the heating sector and low feed-in tariffs combined with high electricity prices.

The Karlsruhe Institute of Technology (KIT) has installed such a system in one of its office buildings and is about to put it into commission. The installed system has a heat pump with a heating capacity of 10.2 kW and a cooling capacity of 10.3 kW in the thermal sector to ensure an optimal indoor climate all year round. The TES used can store 18.6 kWh of thermal energy in cooling mode and 22.6 kWh in heating mode. On the electrical side, a 7.2 kWp PV system and a 10.24 kWh LIB is installed. High-resolution real-life thermal and electrical data are recorded in real time and used to optimize the control of the heat pump and ESS. A rule-based EMS is used to control all components and optimize their operation in real time. The storage technologies are controlled by static priorities and their optimal charging points are scheduled using a power generation prediction algorithm. These charging points increase charging efficiency while preventing the ESS from remaining at a high SOC for long periods, thereby reducing ageing. This paper presents the results of the initial operation and energy management strategy of the whole system.