What Is Solar Energy? How Is It Produced? When Was It Discovered? And Other Details

Solar energy is the radiation from the Sun which is capable of producing heat and causing chemical reactions, or generating electricity that is generated through solar panels.

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•  Solar energy is a renewable energy source due to its inexhaustible supply and its nonpolluting character. 
• The Sun is the largest source of energy received by Earth, but the intensity of the powerful source at Earth’s surface is quite low because of the enormous radial spreading of radiation from the distant Sun. 
• Due to the Earth’s atmosphere and clouds, which absorb or scatter the sunlight is as much as 54 percent.
• The sunlight that reaches the ground consists of nearly 50 percent visible light, 45 percent infrared radiation, and smaller amounts of ultraviolet and other forms of electromagnetic radiation.
• The potential for solar energy is very high as the world’s total daily electric-generating capacity received by Earth every day in the form of solar energy is about 200,000 times.

Though solar energy is free, the cost of its collection, conversion, and storage are pretty high which still limits its utilization in many places.

Solar radiation can be converted into:

• Thermal energy (heat)  
• Electrical energy, 

The former is easier to accomplish.

The difference between solar PV panels and solar thermal panels

Solar PV panels generate electricity, while solar thermal panels generate heat. Though the energy source is the sun for both, the technology in each system is distinct.

• Solar PV works through the photovoltaic effect, in which a photon or the basic unit of light impacts a semiconductor surface like silicon and induces the release of an electron. 
• Solar thermal is the direct heating of water or any other fluids through sunlight. It can be used for domestic purposes for example solar thermal panels are also installed on a roof facing the sun, heating water stored in a hot water cylinder and so providing hot water and heating. 
• Solar thermal can also be used in power stations for larger scale purposes.

When was solar power discovered?

• Solar energy existed as early as the 7th century and was used by humans to light fires by reflecting the sun’s rays onto shiny objects. 
• In the 3rd century B.C. the Greeks and Romans utilized solar power with mirrors to light torches for religious ceremonies.
• By 1839 at the age of just 19, French physicist Edmond Becquerel discovered the photovoltaic (PV) effect while experimenting with a cell made of metal electrodes in a conducting solution. 
• One of the first pioneers of solar energy Dr. Mária Telkes, known as the Sun Queen of solar power, helped the U.S. government to develop a solar distiller that converted seawater into freshwater during World War II.
• In 1954 PV Daryl Chapin, Calvin Fuller, and Gerald Pearson developed the silicon PV cell at Bell Labs which was the first solar cell capable of absorbing and converting the sun's energy into power to run everyday electrical equipment.
• Today satellites and spacecraft are powered by solar energy.

How is electricity from solar energy produced?

• The silicon-made Solar panels are installed in a metal panel frame with a glass casing. 
• The electrons are knocked off the silicon atoms when photons, or particles of light, hit the thin layer of silicon on the top of a solar panel.
• The PV charge is captured by the wiring in solar panels when an electric current (specifically, direct current or DC) is created.
• After that, the DC electricity is converted to alternating current (AC) by an inverter which is the type of electrical current used when you plug appliances into normal wall sockets.

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