Question

How can solar energy be harnessed? Mention any two limitations in using solar energy. How can we overcome these limitations?
[3 marks]

Answer 1

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.

1. It consists of an insulated metal box or wooden box, which is painted black from inside.
2. They are covered with a glass and also have a plane mirror which acts as reflector attached to the box.
3. 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.
4. It is kept in sunlight so that strong beam of sunlight falls over the cooker top.
5. The sun rays pass through the glass sheet cover and get absorbed by black surface and temperature in the box slowly rises up.
6. The heat cooks the food.
[2 marks]

Limitations:
1. The solar cooker cannot be used to cook food during night time (because sunlight is not available at that time).
2. The direction of reflector of solar cooker has to be changed from time to time to keep it facing the sun.
To overcome these limitations, we should use a solar cell.
[1 mark]