Solar-Assisted Heat Pump with Electric and Thermal Storage: The Role of Appropriate Control Strategies for the Exploitation of the Solar Source

Abstract

In the EU, the building sector is responsible for 40% of the global energy consumption for final uses and 36% of the carbon dioxide (CO2) emissions. Heat pumps allow for the replacement of conventional systems based on fossil fuels with the perspective of combining PV and solar thermal collectors. In order to rationalize the use of the solar source, this paper examined the self-consumption electricity share, the CO2 equivalent emissions, and the domestic hot water demand covered by renewable sources which were determined in two opposite climatic conditions. These involved both electric and thermal storage systems and considered two different control strategies. The first is commonly used for the management of air-conditioning systems, the second was specifically conceived to maximize the exploitation of the solar source. Results showed that the latter significantly reduced grid dependence in both locations, determining the direct satisfaction of 76% of the thermal and electric loads through the PV self-consumption, determined by 18 kWp of installed PV and a battery capacity of 24 kWh. In terms of equivalent CO2 emissions, when the two control strategies were compared, a remarkable reduction in emissions was registered for the latter, with percentages ranging between 8% and 36% as a function of PV surface and battery capacity. The analysis of domestic hot water supplies revealed disparities between the two localities: the colder first, relied more on heat pumps for water heating, while the warmer second, benefitted from the large availability of solar radiation.

Achieving Energy Self-Sufficiency in a Dormitory Building: An Experimental Analysis of a PV–AWHP-ERV Integrated System

“…Aneli et al [26] found that when a 4.8 kWp solar PV generator and a 10 kW heat pump were connected, an energy independence of about 34% could be achieved. Perrella et al [27] showed that when a heat pump, an 18 kWp PV panel, and a 24 kWh battery were used together, 76% of the heat and electricity demand could be met. Nicoletti et al [28] conducted a study on the optimal capacity design of air-to-water heat pump (AWHP), PV, and ESS systems considering their economic feasibility for a 20-year driving period.…”