The need for innovative heating and cooling systems to decarbonize the building sector is widely recognized. It is especially important to increase the share of renewables at building level by maximizing self-consumption and reducing the primary energy demand. Accordingly, in the present paper, the results on a wide experimental campaign on a hybrid system are discussed. The system included a sorption module working as the topping cycle in a cascade configuration with a DC-driven vapor compression heat pump. A three-fluids heat exchanger with a phase change material (PCM), i.e., RT4 with nominal melting temperature of 4 °C, was installed on the evaporator side of the heat pump, for simultaneous operation as thermal storage and heat pumping purposes. The heat pump was connected to a DC-bus that included PV connection and electricity storage (batteries). Results showed that the energy efficiency of the heat pump in cascade operation was double compared to compression-only configuration and that, when simultaneously charging and discharging the latent storage in cascade configuration, no penalization in terms of efficiency compared to the compression-only configuration was measured. The self-sufficiency of the system was evaluated for three reference weeks in summer conditions of Athens climate and it was found that up to 100% of the electricity needed to drive the system could be self-produced for a modest cooling demand and up to 67% for the warmer conditions with high cooling demand.

The integration of sorption systems on-board fishing vessels has been explored in the last decade, but the limitations in power density and temperature levels achievable have hindered their application. In the present paper, the integration of hybrid sorption–compression systems was evaluated. Different shipping vessels and routes in seas and oceans were considered in the analysis, with engine powers from 190 kW to 500 kW. The feasibility of series and cascade configurations was studied and the possible benefits, in terms of fuel and CO₂ savings, were evaluated. The analysis, which also considered the payload due to the extra fuel needed to transport the equipment for refrigeration, showed that up to 75% savings can be obtained, with CO₂ emissions avoided up to 20 t/y.

Solar‐assisted heat pumps have the potential to increase the share of renewables in the energy systems for several cases, or to increase the flexibility of smart grids and integrated thermal‐electric grids. The development of such systems requires a comprehensive approach in which technical, market, and social acceptance are all tackled at the same time. Such a holistic approach is the main objective of the present review article. To do so, an investigation is performed by categorizing the integration approaches reported in the literature, exploiting the solar source either as a low‐temperature evaporator source or as supporting the condenser during heating operation. Furthermore, hybrid integration schematics and dual‐source approaches are discussed. Market and social aspects complete the analysis, with the aim of finally identifying the current status; the main drivers and challenges are also addressed. The reported results confirm that the exploitation of solar thermal energy can increase the achievable performance of heat pumps in a broad range of climates. A favorable regulatory/financial framework and informative campaigns for businesspersons and the wide public have been identified as the main solutions to maximize the deployment of the technology in the coming years.

In this paper, cement mortar IN200 integrated with solid–solid PlusIce X25 commercial PCM was fully characterized for the first time via experimental tests and numerical simulations. An experimental setup was designed and built to evaluate the thermal performance of the composite. Experimental results confirmed the expected advantages of the PCM-loaded plaster in terms of inner surface temperature, inbound heat flux reduction, and the enhanced damping effect on the average temperature. The experimental results were used to validate and calibrate a finite element model implemented in COMSOL Multiphysics^® 5.6. The model was adopted to carry out a parametric analysis assessing the influence of PCM mass fraction, phase transition temperature, and PCM mortar thickness. The composite thickness was the most influential parameter, resulting in an energy saving increase from 3.29% to 72.72% as it was increased from 10 mm to 30 mm. Moreover, the model was used in a set of dynamic simulations, reproducing real Mediterranean climatic conditions to capture the transition process for a long period in buildings. The PCM mortar located on the interior side exhibited the highest reduction in both heat flux and inner surface temperature, representing a simple approach to achieving the best thermal comfort conditions.