A specialzed team from the Indian Institute of Technology Madras (IIT Madras) has set up the country’s first solar powered desalination plant in Tamil Nadu.
Built on a 120 square meter (sqm) area near Vivekanada Memorial at Kanyakumari, the plant has a capacity to generate 10,000 litres of freshwater a day.
The Rs 1.22 crore experimental project, funded by the Ministry of Earth Sciences, will be inaugurated soon.
The freshwater generated by the plant has only 2 parts per million (ppm) of dissolved salts. As WHO recommends water with 500 ppm for drinking purpose, Professor Mani said they mix the water generated by the plant with local municipal water.
The IITM team, which include four faculty members and nine PhD students, has been working on the plant from past 18 months.
Professor A Mani of refrigeration and air-conditioning lab at IIT Madras’ mechanical engineering department explained that the surface seawater is pumped in a collector that will trap sun’s radiation and transform it into heat. The sun’s energy will be utilized to heat seawater, which is at 37 degree Celsius, to 70 degree Celsius and above.
The hot water is then pushed into a flash chamber under vacuum and out of that approximate 1 percent will be converted into water vapour, which is forwarded to a condenser and cooled with sea surface water to generate freshwater. Five solar-powered motors will be operated around the plant.
Solar energy is used to heat water and generate power through photo-voltaic panels to operate the plant, which requires about 15kv power a day to exceute the process.
The panels installed at the plant can generate around 324 watts each. The power generated is then converted from direct current to alternating current using an inverter and stored in 14 batteries to provide 30 minute of power backup.
Additionally, Professor A Mani noted that since the plant is powered by the solar power, it can only be operated during the day.