Enhancing Freshwater Productivity of Twin Wedge Solar Still by Temperature Control Through Thermoelectric Sensors and Modules

Solar stills are zero-emission water desalination devices that utilize the abundantly available solar energy to deliver clean water. In remote locations which are deprived of electricity as well as clean and fresh water, Twin wedge solar stills (TWSS) can be utilized to desalinate saline and brackish water. The productivity of TWSS is depends on the evaporation as well as condensation rate which are subjected to the weather constraints namely, the solar energy radiation, the wind velocity along with the surrounding atmospheric temperature. Monitoring the various temperature parameters in the TWSS and controlling them enables the control of freshwater production. In this paper, the yield of TWSS is monitored and controlled using Seebeck effect-based thermoelectric K-type thermocouple sensors for temperature measurements and reverse seebeck effect based thermoelectric modules for increasing evaporation and condensation rate of the TWSS. A Temperature Control Unit (TCU) is developed to acquire the temperature sensor data and control the operation of thermoelectric modules in order to control the production of the TWSS. The TCU is powered by PV with a battery backup system for remote location operation. The productivity of the system increased from 0.69 – 1.38 liters/m
²
per day to 3.28 – 3.61 liters/m
²
per day, through proposed Temperature Control strategy through Thermoelectric sensors and modules. The proposed system is 1.4 times more profitable than TWSS equivalent to the area of proposed PV powered system.