Wind Energy Based Reverse Osmosis System for Desalination of Brackish Water
The development of Renewable energy based desalination systems is important on islands and in the coastal areas.
This paper presents design of such system proposed to be located at Devgad which is one of the potential sites vetted by
National Institute of Wind Energy (NIWE) for wind energy project in the coastal region of Maharashtra. Most past studies of
wind powered desalination used the wind power indirectly that is it was used to generate electricity first and then the
electricity was used for desalination by RO process. In this work wind energy is used directly to raise the feed water pressure
for RO desalination. It involves less energy conversion and thus higher efficiency.
The brackish water desalination system presented here comprises of 10 kW wind turbine which converts wind energy
directly into pressure energy. The system can produce freshwater at total dissolved solids (TDS) of less than 100 mg/l from
brackish water up to 10,000 mg/l of total dissolved solids (TDS). The rated maximum capacity of plant is 31.26m3/day of
clean water at average wind velocity 5.81m/s. The recovery rate of RO unit is about 40 to 50 percent. The pre-treated
seawater passing through the Reverse Osmosis (RO) membrane is separated into clean water and brine. The brine from RO
has a high pressure that has been reused to pressurize the feed water using pressure exchanger, which significantly reduces
power consumption of the system. The design procedure developed in the present study may be adopted for systems working
under similar conditions.
Keywords- Renewable energy, Desalination, Wind energy, Reverse osmosis, and Pressure exchanger.