Question

Why is it not possible to make use of solar cells to meet all our energy needs? State at least three reasons to support your answer?

Answer 1

Hint Solar cells convert the light coming from the sun into electricity. Efficiency of solar cells is not high and we need a huge amount of energy for our daily needs.

Complete step by step answer
Solar cells are devices which convert the energy of sunlight into useful electricity during a phenomenon called photovoltaic effect. This is an amazing technology with huge future prospects.
However, solar cells as of now cannot meet the current energy need of the world for quite a number of reasons. These reasons are
-Solar cells, since they get the input energy from the sun, do not generate any electricity at night. Technically, the sun is not out for about 12 hours a day, hence the solar cells are inactive during this period. Even in the day when the sun is out, its intensity is not constant throughout the day.
-During the winter, or rainy seasons, the solar cell is dormant. We know that during the winter, the sun is barely out and even when it is, the intensity is usually very low, hence the solar cell does not generate much electricity during the period.
-The efficiency of a solar panel is actually very low. The best commercial solar cells possess an efficiency of only about 20 per cent. Hence, even during the summer, the electrical energy provided by solar cells is very low as compared to today’s energy demands

Note
In application, since they individually produce limited energy, solar cells are often combined into solar modules then wired together and commercialized as solar panels. This reduces the inefficiency that would have been created by designing one large solar cell, and that created in wiring separate solar cells independently.