Modeling of solar assisted heat pumps combined with photovoltaic thermal modules

This work summarizes the performance of a Solar Assisted Heat Pump integrating Photovoltaic thermal (PV/T) modules. This configuration reduces the disadvantage of low temperature heat recovery typical of PV/T modules as the fluid temperature is used to drive the heat pump evaporator instead of an end-user and, consequently, can be close to the ambient one. A detailed model featuring real components is developed in MATLAB ® to correctly predict the SAHP performance as function of the design parameters (number of PV/T modules) and ambient conditions (solar irradiance and ambient temperature). In addition, an optimization tool was combined with the model to maximize the COP (Coefficient of Performance) by varying the water flow rate circulating in the PV/T panels. Results outline the benefits of this concept with respect to conventional air/water heat pumps in particular when the ambient temperature is below zero as the frost formation issue is not present. COP reaches high values, between 2.5 and 4.9 in the case with 12 PV/T panels and between 2.2 and 6.2 with 24. Advantages in terms of electricity production are outlined as well, with an increasing of 8-9% of the power produced.