What Is Solar Energy?


The simplest definition of solar energy, as you surely would have learnt in your physics tuition class, is the energy coming from the sun.

Well, the first question was a simple one. Let’s look at another question, a little more challenging than the first one.

Do you know how much solar energy the world receives?

The answer is approximately 770 trillion kilowatts. That’s quite a lot, isn’t it? As a matter of fact, it is 5,000 times more than all other energies combined.

Solar energy is of two kinds—electric energy and thermal energy.

Difference between thermal and electric energy

Thermal energy is everywhere. It’s kinetic energy, which makes the environment hot. In fact, we use this energy in many ways. For instance, we use kinetic energy to dry our clothing. Another common use is for heating water for use.

Electric energy, without a doubt, is no less important. It is usually used more widely than most other energy types. Most of us recognize electric energy as electricity. The heat from the sun is tapped and converted into electric energy, which then is used for running electric equipment, such as household appliances, computers, lightening, etc. Now we have even electric cars, which not only help reduce our carbon footprint but are also cheaper than traditional cars.

A successful program of solar energy has two important features: storage as well as collectors. Solar energy is available for only part of a day. It is there only during daytime, and that’s why storage is required. Controls are treated to make sure storage systems work safely and economically.

The availability of this energy is dependent on three things:

  • Place
  • Time
  • Weather

Solar energy is free, but that certainly doesn’t mean it has no disadvantages whatsoever. There are certain disadvantages associated with it, but it also offer many important benefits. Let’s take a look at both.

Advantages of Solar Energy

Solar energy is free. This is a big advantage, although not the biggest (which is the next one). However, converting solar energy into electric energy requires investment, often more than a conventional power plant. Having said that, in the long run, electric energy derived from solar energy comes out to be way cheaper.

Solar energy is limitless and that’s its biggest advantage. There’s no danger of solar energy running out.

Solar energy is very storable. While it is true that it is available only during the daytime, with help of an efficient storage system, the energy can be stored for later use.

Solar energy is pollution free, which you might have learned in your A level Physics tuition classes. Our environment doesn’t suffer when we use solar energy to produce electricity.

Disadvantages of Solar Energy

Solar energy is not a viable option in places which get little sunshine.

To convert solar energy into electric energy a lot of land area is required. This may not be possible in many cities.