Solar Energy is the energy obtained from the sun. The sun gives out a vast amount of light and heat. It is only a little less than half (47%) of solar energy which falls on the atmosphere reaches the earth’s surface. If we could use just a small part of this energy it would fulfill all the country’s need for power. Solar Energy has advantages and also certain limitations.
SOLAR ENERGY DEVICES:
The energy from the sun can be harnessed to provide power. The various devices used for harnessing the sun’s energy are called solar energy devices.
Solar cells ( Photovoltaic devices) are made up of silicon that converts sunlight directly into electricity. The solar cell produces electricity without polluting the environment. Since it uses no fuel other than sunlight, no harmful gases, no burning, and no wastes are produced. These can be installed in remote and inaccessible areas ( forests and hilly regions) were setting up of power plant is expensive.
Uses of Solar Cells:
• It can be used for street lightning, traffic signals, water pumping, battery charging system etc.
• It is used in artificial satellites and space probes.
• It provides radio and TV transmission to remote areas.
• It is used in calculators, electronic toys, and watches.
Arrangement of many solar cells side by side connected to each other is called a Solar panel. The capacity to provide electric current is much increased in the solar panel. But the process of manufacture is very expensive. Installation of solar panels in homes helps in combating the harmful emissions of greenhouse gases and thus helps reduce global warming. Solar panels do not lead to any form of pollution and are clean. They also decrease our reliance on fossil fuels (which are limited) and traditional power sources. These days, solar panels are used in wide-ranging electronic equipments like calculators, which work as long as sunlight is available.However, the only major drawback of solar panels is that they are quite costly. Also, solar panels are installed outdoors as they need sunlight to get charged.
SOLAR COOKER :
It consists of an insulated metal box or wooden box which is painted from inside to absorb maximum solar radiation. A thick glass sheet forms the cover over the box. The reflector is the plane mirror that is attached to the box. The food is cooked by energy radiated by the sun .A solar cooker, or solar oven, is a device which uses the energy of sunlight to heat food or drink to cook it or sterilize it. High-tech versions, for example electric ovens powered by solar cells, are possible, and have some advantages such as being able to work in diffuse light.
SOLAR THERMAL PLANT:
Solar thermal power plants are electricity generation plants that utilize energy from the Sun to heat a fluid to a high temperature. This fluid then transfers its heat to water, which then becomes superheated steam. This steam is then used to turn turbines in a power plant, and this mechanical energy is converted into electricity by a generator. This type of generation is essentially the same as electricity generation that uses fossil fuels but instead heats steam using sunlight instead of combustion of fossil fuels. These systems use solar collectors to concentrate the Sun’s rays at one point to achieve appropriately high temperatures.
Advantages of Solar Energy:
• It is available in abundance in India and is free of cost.
• It is a renewable source of energy.
• It can be used for generating electricity or heat.
• It does not cause Pollution.