Energetic and economic analysis of a solar assisted heat pump for pasteurization process

In the present paper, the energetic and economic analysis of a solar-assisted heat pump for an industrial pasteurization process is investigated. The considered system consists of thermal energy storage, a water-to-water heat pump and a solar field made up of both photovoltaic-thermal collectors and evacuated tube collectors. A mathematical model of each component of the system is built and validated, while the overall model of the system is built with a bottom-up approach. The energetic and economic analysis is performed on a yearly basis varying the storage size and the solar field size and considering a boiler-only scenario as the reference system. The results show that, from the energetic point of view, the best system could provide up to 90% of the energy required by the process and, consequently, significantly reduce auxiliary boiler consumption. On the other side, from an economic point of view, the best solution provides a minimum payback time approximately equal to 8 years with 14.4% internal rate of return.