how can solar energy be harnessed what are the limitation of using solar energy how are these limitations overcome
Answers
Solar energy can be harnessed by using a solar cooker.
A solar cooker is a device which is used to cook food using solar energy.
It consists of an insulated metal box or wooden box, which is painted black from inside.
They are covered with a glass and also has a plane mirror which acts as reflector attached to the box.
The food to be cooked is placed in a metal container and the black painted cooker is kept in box and covered with glass sheet.
It is kept in sunlinght so that strong beam of sunlinght falls over the cooker top.
The sun rays pass through the glass sheet cover and get absorbed by black surface and temperature in the box slowly rises up.
The heat cooks the food.
Limitations :
The solar cooker can not be used to cook food during night time (because sunshine is not available at that time).
The direction of reflector of solar cooker has to be changed from time to time to keep it facing the sun.
To overcome limitation, we should use a solar cell.
Answer:
Methods of harnessing solar energy:
Solar Cooker: Solar cooker is a simple device. It is composed of a rectangular box with a mirror at the top. The box has a glass cover. Mirror is kept in erect position so that reflected sunlight can go inside the box. Utensils are kept in the box. Glass cover on top prevents heat from escaping the box.
Solar Cell: A solar cell is also called photovoltaic cell. It converts solar energy into electrical energy. Electrical energy thus produced needs to be stored in inverters so that it can be used even during night.
Solar Furnace: Solar furnace is made of concave mirror. The heating device is kept at the focus of this furnace. Heat from sun is concentrated at the focus which helps in generating lot of heat. Solar furnace can be used to heat water and steam generated by this process can be used to generate electricity.
Limitations of Solar Energy:
Can be harnessed only at those places which get plenty of sunlight.
Cannot be harnessed beyond certain latitudes.
Cannot be harnessed during night.
Current technologies are very costly.
Ways to overcome limitations: Batteries can be used to store electrical energy from photovoltaic cells. Cheaper technologies need to be discovered.