Experimental Investigation of Solar Powered Reverse Osmosis Desalination
Keywords:
Carbon filter, Desalination, Flow meter, Reverse osmosis, Photovoltaic cells, EthiopiaAbstract
Pollution and over exploitation of groundwater aquifer and surface water have led to a decrease of quality and availability of natural water resource in many regions. This situation has led to elevated total dissolved solids (TDS) beyond standards and facilitates toxic metals accumulation and other problems like staining and/or precipitation. One of the treatment options for an elevated total dissolved solution is desalination using a solar driven reverse osmosis system. The northern part of Ethiopia has short rainy season and long dry weather with clear sky radiation. Solar radiation ranges from 5.46 kWh/m2/day in August to 6.82 kWh/m2/day in April, with an average of 6.09 kWh/m2/day.
This paper deals with application of reverse osmosis, driven by desalination system using solar energy, to supply safe drinking water for the rural areas of northern Ethiopia. Reverse osmosis due to its low energy consumption is one of the best desalination alternatives. Solar powered reverse osmosis system was developed and installed at Mekelle University. The main components are photovoltaic panels, two DC powered pumps, carbon filters, and flow meters. The system made to operate in a variable power, flow, and pressure considering the naturally varying irradiance throughout the day. The entire process of irradiation potential measurements, the amount of energy generated using solar panel, and the amount of TDS is discussed. The feed water with nearly constant TDS around 2800 ppm from the study area has reduced to fairly constant TDS of about 100 ppm after desalination. The average desalination capacity of the system is 50 litres per hour.