UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Assessment of using a Tesla expander to harvest waste heat from a photovoltaic panel for residential applications Yousefnejad, Roozbeh


Solar energy is an abundant source of energy for generating electricity. The main challenge is that the solar photovoltaic (PV) panels are typically used in regions where solar radiation is high; consequently, the temperature of the panels will increase, and the efficiency of the panel will decrease. Water cooling systems are typical methods of cooling, and the resulting hot water can be used for space heating or other purposes. In regions that have high solar radiation; however, the demand for hot water is not high. In this research, we investigated combinations of PV panel, an expander with a Rankin cycle, and a new working fluid to generate extra electrical power for residential applications. To achieve the goal, different working fluids were analyzed, and R-245-fa was found to be the ideal fluid for this purpose. To design the cooling system, a new algorithm was developed to find the optimal number, spacing, and diameter of the cooling tubes. The accuracy of the new model was determined by a CFD simulation, and for possible future industrial uses, a user-friendly application was developed using COMSOL® Multiphysics. A Tesla expander was built and tested, and the torque was measured experimentally. The results were compared to typical methods of modeling the turbine to determine the accuracy of each model. Finally, for real data for a day in Egypt, the system was analyzed, and the cooling cycle was shown to yield an average improvement of 12% in terms of generated power.

Item Citations and Data


Attribution-NonCommercial-NoDerivatives 4.0 International