Solar Energy

The nearest star to us, sun! There is no doubt that life isn’t possible on earth without the energy from our sun. It is actually the main power station for the plant Earth where energy is produced and then distributed. All the energy that we are using on this plant right now is the Sun Power packed into diffrent packets sometimes through ages. Solar panels and solar heat collectors are just mankind's effort to harness more and more of this clean source of energy directly so there is no byproduct of extracting the energy.

Solar Energy

The energy from the sun can be classified into two distinct forms-

  • Photons, meaning the energy from the photons blasting out from the sun. Visible light coming out of the sun is a part of this.

  • Heat energy, the warmth that you feel when in the sunlight.

The sun is a main-sequence star which generates its power using nuclear fusion. Through a continuous process, hydrogen atoms are fused to form helium giving out energy as it's byproduct. It is important to note that mankind has not yet able to setup any controlled nuclear fusion plants on earth to harness the energy.

In its core, the Sun fuses 500 million metric tons of hydrogen each second.

The Sun releases an estimated 384.6 yotta watts (3.846×10^26 watts) of energy!

On earth, we get approximately 1000 W/m2 for a surface perpendicular to the Sun's rays at sea level with a clear day.


The two types of solar energy harnessing machines you might have been seeing everywhere are solar panels and solar heat collectors. But as discussed all the fossil fuels you are using even now are nothing but the sun's energy packed and stored. The food we eat also has energy which was ultimately released from the sun. Let’s see some prominent of them and how they are connected to the solar energy.


Fossil Fuels

They comprise of Coal, crude oil and natural gas; all of which we use frequently in our day to day life.They are called fossil fuels as they are formed from fossilised, buried living matter (plants and animals) that lived over millions of years ago. All the types of fossil fuels have their drawbacks while extracting energy from them. Petroleum literally meaning rock oil, is a product made from crude oil powers most of the cars on road and it is also used to make various environment harming products like plastic and coal is considered to the the most carbon intensive fossil fuel we can burn.


So how do they have solar energy in them? As they are the remains of plants and animals they have the energy which the living matter consumed over their lifetime. Plants gain energy through photosynthesis and animals through eating plants. The photosynthesis process involves taking in energy from the sun aka solar energy and carbon-di-oxide from atmosphere to convert them into oxygen and carbohydrates. Thus, all the energy those fossils have in them is originally the energy radiated out by the sun.


Photosynthesis:

It’s hard to talk about the energy from sun but forget about our 4th grade lesson of photosynthesis. It’s the process through which plants take in the energy from the sun to make food for themselves. Plants have the protein called chlorophyll in their cell which is used to capture sunlight to carry out a chemical reaction that converts water and Carbon-dioxide to sugar. All the animals including humans live off this food that plants produce, directly or indirectly. Also, not to forget life supporting oxygen is a byproduct of this reaction!


Direct Methods to use solar energy:

The current direct devices of converting sunlight to usable energy are solar photon light collectors and solar heat collectors. Though I have explained them in short below, you can learn more about them in detail through our other articles here.

As the name suggests, the devices which work on sunlight collect the photos from the sunlight to generate usable energy. They consist of semi-conductor materials doped in P-N junction. The layer exposed to the sun will have extra electrons than the one below. Thus when the suns light (photon) knocks the electron out of the top layer using a sophisticated interconnections of busbars and other devices the the movement of electron (basically electricity) is tapped into.

There are many applications for solar heat capturing devices like heating water, cooking food, home temperature control, etc. They fundamentally capture the heat from the sun and not the light. A parabolic shape mirror is used to concentrate the heat over a wide area on to a concentrated spot so higher temperature is achieved.


If you have any questions or want to learn more about adapting solar energy for your own use, check out our homepage and contact us for any query you have.