What Is Solar Pond? Advantages of Solar Energy and Solar Technology
Solar Pond is one of the most promising technologies in solar energy utilization for varied purpose. It is a large scale energy collector with internal heat energy by various ways, such as process heating, refrigeration and drying.
Air becomes lighter of rises above when heated Similarly, When water is heated by the sun ray, hot water from the bottom of the pond rises and its reaches the surface, and loses whatever heat it has gained from the atmosphere. The result is that the pond water remains at nearly atmospheric temperature. To prevent this heat loss by convection in a solar pond, salt is dissolved in the bottom layer of the water. This makes the water too heavy to rise (even when hot) to the surface. Thus the solar energy remains entrapped in the pond.
A solar pond consists of three zones. The top zone or the surface zone remains at atmospheric temperature and has little salt content. The bottom zone is very hot (110 degree C) and salty with specific gravity of about 1.20. It is this zone which collects and stores the solar energy in the form of heat and is, therefore, known as storage zone. Separating these two zones is the gradient zone that acts as a transparent insulator, permitting sunlight to reach the bottom zone and its thermal energy to remain entrapment there. The useful energy is then withdrawn from the solar pond in the form of heat.
Solar pond have three major advantages over the other solar technologies.
1. They have a low cost per unit area.
2. They can be constructed over large areas enabling the diffused solar radiations to be concentrated on large scale.
3. They can supply energy even during the monsoon season.
India is the first Asian Country to have a solar pond in Bhuj (Gujrat). The Bhuj solar pond has been designed to supply about 220 million kilowatts of thermal energy per annum, about 1,25000 kilowatts of electricity per annum, and about 80,000 liters of potable water per day.
