Question

How can solar energy be harnessed? Mention any two limitationsin using solar energy. How are these limitations overcome?

Answer 1

Solar energy is simply the light and heat that come from the sun.
People can harness the sun's energy in a few different ways:
Photovoltaic cells, which convert sunlight into electricity.
Solar thermal technology, where heat from the sun is used to make hot water or steam.
Passive solar heating, which can be as simple as letting the sun shine through windows to heat the inside of a building.
Below is the working of a solar cell which harnesses solar energy:
A solar cell is an electronic device which directly converts sunlight into electricity. Light shining on the solar cell produces both a current and a voltage to generate electric power. This process requires firstly, a material in which the absorption of light raises an electron to a higher energy state, and secondly, the movement of this higher energy electron from the solar cell into an external circuit. The electron then dissipates its energy in the external circuit and returns to the solar cell. A variety of materials and processes can potentially satisfy the requirements for photovoltaic energy conversion, but in practice nearly all photovoltaic energy conversion uses semiconductor materials in the form of a p-n junction.
The basic steps in the operation of a solar cell are:
the generation of light-generated carriers;
the collection of the light-generated carries to generate a current;
the generation of a large voltage across the solar cell; and
the dissipation of power in the load and in parasitic resistances.
Below is the diagrammatic representation.
Limitations in using solar energy:

• Available during day time/sunny days.
• Requires huge installations and costly.

To overcome limitation we can make use of a solar cell.