Sunlight is the light and energy that comes from the Sun. When this energy reaches the earth’s surface, it is called insolation. What we experience as sunlight is actually solar radiation. It is the radiation and heat from the Sun in the form of electromagnetic waves.
We can use this energy as solar thermal & for electricity generation i.e. Solar PV.
In Solar Thermal, heat energy from sunlight is utilised for different heating applications such as solar water heater, solar parabolic collector, solar boilers, solar cooker, Solar Dryer etc.
Most popular application of solar thermal is the solar water heater. The latest technology used in the solar water heater is Evacuated vacuum Collector technology, In EVC technology black circular tubes are used. These tubes absorb maximum heat energy from sun rays and transfer the same to water inside it because of this water is heated. The number of tubes required ar decided by Volume and temperature of water required.
Tubes have been deliberately kept slanting to get the natural circulation of hot and cold water.
This type of water heater finds the major use for domestic as well as commercial water heating purposes.
Solar Cells also called as solar PV which converts sunlight directly into electricity.
The photovoltaic cell (PV cell) is a specialized semiconductor material that converts visible light into direct current (DC).
As we can see in semiconductor materials When a sunray, full of photons hit a solar cell, they knock electrons loose from their atoms. If conductors are attached to the positive and negative sides of a cell, it forms an electrical circuit. When electrons flow through such a circuit, they generate electricity.
Solar Cells are tiny in size hence they produce very little direct current, Many Solar cells are connected together to form solar module and similarly many solar modules are connected together to form a solar panel which produces a significant amount of direct current.