What is Solar Energy or solar power?

History of Solar Energy-Overview

There are many renewable energy sources available, but the most common & freely available source is Solar Energy. Sun is the largest source of energy. Every day, sun rays fall on the earth. But in the early time, there is no equipment available to convert these rays into electricity. In the 7th century B.C, the use of solar energy started for local use. Like producing fire with a magnifying glass, grain heating, roof heating in winter seasons & many more. The most common use of solar power in early time for sunrooms. Homes are made in form of sun rays that directly fall into the rooms from the large windows. In some cases, mirrors are using to divert sun rays into your home.

Now there are so many advanced technologies are present which can convert sun rays into electricity. Let us see in detail information about Solar Power, Solar Energy Companies, benefits & its future.

What is solar energy?

Solar energy is a renewable energy source. It is harnessed by using various technologies & converting it into electrical or thermal energy. Solar power is an abundant source of renewable energy available all over the world.

It is a free & large source of energy received on the earth. But 100% of sunlight is not receiving on the earth’s surface. Around 50% to 55% of sun rays are getting absorbed by the earth’s atmosphere & clouds. And the remaining 40% to 45% of sunlight reaches the earth’s surface.

It is the tremendous energy coming on the earth’s surface. These sun rays are responsible for the energy generation & harness by using the below methods.

How to harness solar energy?

As it is a free source of energy, so it is necessary to harness solar power into a usable form. Three methods are available to harness solar energy. Let’s see these methods in detail.


Photovoltaics (Solar cells) are devices made by semiconductor materials, which can convert sunlight into electricity. In the semiconductor material naturally, the electronic process happens & sun rays are getting converting into electricity.

When the sunlight falls on the outer surface of the concentrating photovoltaics, electrons break their atomic bonds & start flowing in one direction. These forced electrons in one direction create the flow of the electric current.

Solar photovoltaic cells are not 100% efficient to generate solar energy. Because few of the rays are only absorbed & the remaining are reflected or creates heat only instead of electrical energy.

Due to the scale-up of the photovoltaics industry, the cost is decreasing & use is increasing rapidly. The cost of the photovoltaics cell is dropped up to 60% as compared to the last decades.

Concentrating solar power

This power plant uses mirrors placed on the ground to concentrate solar power. These mirrors concentrate the solar rays onto the tall thin tower. This concentrated solar energy gets used to heat water & generated steam imposed on the impellers to drive traditional steam engines & turbines.

This turbine generates electricity & use electricity whenever require. Advantage of the concentrating solar power is, it uses molten salts to store heat.

The following are the concentrating solar power technologies that exist.

1-Parabolic Trough

It uses parabolic mirrors to get placed in the line. On that mirror, the receiver tube gets placed as per the focal point of the curved mirrors. These mirrors having a solar tracking mechanism & track the position of the sun. According to the position of the sun, mirrors can get adjusted & concentrate sun rays onto the receiver tube.

Liquid present inside the receiver tube absorbs the heat & can absorb temperature above 750-degree Fahrenheit. This heated liquid passes through the heat exchanger & heat the water to form steam. The steam is imposed on the conventional turbine to generate electricity.

Generally, the liquid used in the receiver tube is synthetic oil.

2-Compact Linear Fresnel Reflector

In this type, low-cost flat mirrors get placed in parallel. Sunrays that fall on these mirrors are concentrate on the elevated receiver. These flat mirrors can divert more sun rays onto the receiver tube. This receiver consists of a tube through which water flows. Solar energy heats the water & generates high-pressure steam utilized for electricity generation or industrial applications.

3-Power Tower

In this system, a central receiver tower is used to collect sunrays diverted by the mirrors placed on the periphery of the tower. These mirrors are flat & movable known as heliostats. Computer-controlled mirrors can track the position of the sun & focus energy on the receiver. This heat gets utilized to generate steam to drive a central generator.

In the new design, molten salt uses as a working fluid. This molten salt having a high heat-absorbing capacity, which can store more heat. This heat gets used to boil the water.

Solar heating & cooling

Passive Heating

In passive heating, buildings & homes are designed in such a way that, it can receive more sun rays into the home. So that it can reduce the fuels required to heat your home in the winter seasons.

Homes having a large window facing to the south & north, through which more sun rays come into the homes. These sun rays warm the air & heat the exposed parts of the home.

Active Heating

In the active solar heating system, mechanical devices used to trap the heat. The heat generated from the solar array gets utilized to heat the water & steam is generated.

In the liquid system of the active heating, water is pumped into the flat plate collector through pipes. Sunrays fall on the flat plate collector transfer heat to the metal plate. This heat is transferred to the flowing fluid. Then the fluid is pumped into the storage tank which is insulated. During the space heating, this heated fluid is pumped into the tubes connected to the floors & ceilings.

Especially this technology is used in America or the cold weather countries for commercial, residential & industrial applications. Countries like America are investing in solar heating & cooling technology instead of imported fuels.

Transparent Solar Windows

These transparent solar panel windows can allow to get transfer the sun rays & also generate electricity. In this technology, sun rays falling on the window are get diverting to the edge of the window.

On edge of the window, small solar panels are placed, which can generate electricity. It is a new advanced technology and many scientists are working on it to increase its electricity generating capacity.

Solar energy companies

Orsted (DNNGY)

Denmark based multinational company pioneer in a renewable solution. The revenue of the Orsted is 34.96 billion dollars. This company is in the sector of wind energy, bioenergy & others.

Iberdrola SA

Iberdrola SA is a Spain-based MNC having revenue of 34.22 billion dollars. This company is in wind energy, solar thermal energy, mini-hydro energy, biomass & photovoltaics sectors. Iberdrola SA can operate from the US. Uk, Spain, and Portugal. 

Jinko Solar

It is one of the largest companies in the field of Solar Energy. The headquarters of this company is in Shanghai, China. Its revenue is 33.95 billion dollars.

Canadian Solar

It is the second-largest company in the manufacturing of PV modules & solar energy solutions. The headquarters of this company is in Ontario, Canada.

Trina Solar

Trina Solar is a Chinese based company, and headquarter is in Changzhou. This company provides solar modules for commercial & residential purposes.

SunPower corporation

It is a Silicon Valley-based company & leader in the innovation in the solar system. SunPower corporation provided an innovative solar panel system with high efficiency to the application in commercial & residential.

Advantages of Solar Energy

  1. It is a renewable source of energy.
  2. It can reduce your electricity bills.
  3. Maintenance cost is low.
  4. A solar power system gets installed anywhere.
  5. Efficiency is increasing day by day due to innovations.
  6. Solar energy systems becoming more compact to reduce space requirement.

Disadvantages of Solar Energy

  1. The high cost of installation & their materials.
  2. In the winter months, electricity generation is lower due to cloudy weather.
  3. Space requirement is more.
  4. At night, there is no electricity generation.
  5. It requires better battery storage to store energy.

Solar energy future

In the coming time, the cost of the solar power system will get reduced. The solar power system will become compact & having high efficiency. Old solar technologies will get vanish & advance, compact & efficient solar power systems will rule the world. Maximum sun rays are getting harnessed. Solar energy is available free of cost & it does not cause pollution, due to that it will take the position of fossil fuel. 

Leave a Reply