Techno-economic analysis of a hybrid photovoltaic system for freshwater and power generation using silica gel

Photovoltaic (PV) solar power generation technology is globally popular because of the sustainability of solar energy and its zero-carbon emissions. However, the high operating temperatures, resulting from the photothermal effect, limit both photovoltaic conversion efficiency and the operational lifespan of PV cells. The integration of evaporation cooling with self-adsorption and desorption has become a promising approach for cooling PV panels and generating both electrical power and freshwater. This paper investigates the techno-economic performance of PV adaptive cooling utilising desiccant materials that capture moisture from the air. This water collected through this method is subsequently used in evaporative cooling to lower the temperature of the PV panels, thereby enhancing their efficiency while generating freshwater. A mathematical framework for photovoltaic panels cooled by silica gel has been introduced to analyse heat and mass transfer processes under two different weather conditions, dry and wet region climates. This study aims to evaluate the impact of various weather factors, including solar irradiance, relative humidity, ambient temperature, and wind speed, on the technical and economic performance of photovoltaic (PV) systems, as well as their ability to collect water under different climatic conditions. A MATLAB numerical simulation has been developed to assess the impact of the proposed cooling approach on the efficiency of solar panels, the electricity generated, and the freshwater produced. The research also investigates how the thickness of the sorbent material impacts the performance of PV systems, encompassing electricity production, water harvesting, and economic considerations. The results show that the maximum reduction in average cell temperature is 8.63°C when the system operates under dry weather conditions with a one cm-thick layer of silica gel. Furthermore, the best improvement achieved in energy efficiency under the same dry conditions is 6.18% but with varying thicknesses of the cooling layer. Regarding water harvesting, the maximum amount collected is 2.069 kg/m² in dry weather with a 3 cm thick layer of silica gel. While enhancing its water harvesting ability, increasing the thickness of the cooling layer, however, negatively impacts the PV thermal performance. Results also demonstrate that the self-adaptive adsorption/desorption technique is more effective in dry weather conditions. Regarding economic analysis, the results also show that the use of such a Levelised cost of electricity is more feasible than in wet weather, especially with a thickness of 2 cm, with net present value (NPV) of 79.17 $, a payback period of 6.48 years, Levelised cost of electricity (LCOE) of 0.0773 $/kWh, and Levelised cost of water (LCOW) of 0.057 $/L.