Influence of dust accumulation on the performance and economics of a flat plate solar collector system

Dust accumulation on the active surfaces of solar energy harvesting devices reduces their efficiency while increasing the overall cost of production. This study aims to assess the impact of dust accumulation on the performance and economics of a Solar Water Heating System (SWHS) equipped with flat plate solar collectors to meet the hot water requirements of a typical residential house located in Dhahran, Saudi Arabia. Mathematical models and MATLAB computer code are developed and used, in hourly-based simulations, to optimize the sizes of the SWHS components. As a reference case, SWHS with a clean active surface is optimized first. Then, the optimization process is repeated for SWHWs cases with dust accumulation densities of χ=0.7,1.4 and 2.1mg/m². For the clean active surface case, the optimal sizes for SWHS components are a 1 m³ storage tank and 9 m² collector area. To fulfill the identical hot water demand, with the presence of dust, the storage tank capacity and collector area increased to 1.1 m³ and 11 m² for the dust accumulation density of χ=0.7mg/m², 1.3 m³ and 13 m² for χ=1.4mg/m², and 1.4 m³ and 19 m² for χ=2.1mg/m², respectively. The results show that Cost of Energy (COE) is $0.128/kWh for the clean surface case; however, it is increased by 15, 34, and 71 % for the three considered dusty cases, respectively. These findings demonstrate the effect of dust accumulation on both sizing and cost-effectiveness of SWHS highlighting the importance of incorporating appropriate dust mitigation solutions in arid climates.