Question 24: How can solar energy be harnessed? Mention any two limitations in using solar energy. How are these limitations overcome?
Answer:
Solar energy can be harnessed directly by using solar cookers, solar heaters or solar cells.
In a solar cooker, the heat energy by the sun is used for cooking purposes. Solar cooker is a device which converts solar energy into heat that is used to heat, cook and pasteurize drinks, food and other materials by using direct sunlight. Solar cookers covered with the glass plate and some solar cookers achieve high temperature by using the plane mirrors. Glass sheets provide warmth in the green house, receives less amount of solar radiation.
In a solar heater, the heat energy is used to heat the water.
Solar cells are used to convert heat energy into the electricity. Solar cell device is small in size, bluish- black in colour. These are made of p & n type semiconductor. These small solar cells are combined together to form a solar module, then these solar modules themselves combined to form a bigger unit called solar panels. Photovoltaic cells are attached to the panels to convert sunlight into electricity. As we know, light consists of photons when these fast moving photons stick the solar panel; they are captured and convert them into the flow of electrons which generate electric current. A single cell can generate a few volts of electricity. So, a solar panel job is to combine the energy produced by many cells to make a useful amount of electric current and voltage.
Limitations:
1. Solar energy cannot be used or available at night or when the sun is hidden in the clouds which happen mostly in the winter or the rainy days.
2. The domestic use of solar cells is not possible due to high cost.
And, these limitations can be overcome by the following ways:-
- First limitation can be overcome by converting solar energy into electrical energy and storing them for the future way.
- Second limitation is overcome by taking certain steps through the government by reducing the price of solar cells.
Add Comment