Our Universe is mainly made up of two things, matter, and energy. Among them, energy is the only responsible factor for all the actions of the cosmos.
Our civilization is mainly dependent on energy consumption, as the rate of energy consumption has been increasing with human society’s growth, which has brought drastic changes in our universe’s development. We can not imagine how much more this civilization will evolve in the future with this rate of enormous energy consumption. This is why people are trying to find alternative and reliable sources of energy and available energy sources. Scientist is trying to find renewable energy sources (energy used repeatedly without depletion).
In this article, we are trying to discuss the most efficient renewable source of energy that is available and will be available for many more centuries called Solar Energy.
Sources of Energy Consumption with Time:
The scenario of Global Energy consumption change rapidly: In the early 19th century, there was only one primary energy source, wood. As the era started to
progress, another energy source, coal, came into use. Slowly in the mid 19’s, fossil fuels’ primary consumption of energy was taken by fossil fuels; this included oils, natural gas, and coal. But as these fossil fuels are a non-renewable energy source, people feared that the excess use would end it up soon. People needed to find an alternative renewable energy source that will last for a more extended period. In search of an alternative energy source, we found nuclear, solar, wind, geothermal, hydroelectric, biogas, etc. Solar energy has become a cost-effective, high efficiency, and long stable energy source among these renewable energy sources. In our discussion, we shall discuss:
- What solar energy is?
- How solar energy reaches Earth?
- How can we absorb solar energy?
- Conversion of solar energy to other energy sources like heat energy, electrical energy, etc.?
- Storing of Solar Energy?
Understanding Energy before Solar Energy:
Before we jump into solar energy, we must know the essence of energy. If someone asks what the definition of energy is, we say it’s “The ability to do any work.” Behind any action, movement is the fundamental necessity. In simple words, this movement through a particular amount of force refers to work done. And to accomplish this action or work, the thing required is energy. For example, When a car runs, the car’s movement refers to the vehicle’s job or activity, and the reason behind its move is its energy, and in this case, the source of energy is fuel.
What is Solar Energy:
Do you know that the temperature of the surface of the Sun is 6000 Kelvin? But the question is where from an extensive amount of heat energy is produced? The core of the Sun is tightly bound with a tremendous amount of pressure. Nuclear fusion takes place inside the Sun, where Hydrogen converts to Helium. In this process, an enormous amount of energy is released in heat and photons(light). Some part of this heat and light energy reaches Earth every day, popularly known as Solar Energy. This energy makes the Sun a reliable and abundant source of renewable energy.
How Solar Energy reaches the Earth:
Solar energy goes our Earth in light and heat; these light waves are scientifically known as electromagnetic radiation(waves having electrical and magnetic fields perpendicular to each other and perpendicular to the dir. of propagation). When these light waves reach the Earth’sEarth’s atmosphere, it contains about 50% infrared light, 40% visible light, and 10% ultraviolet light. When this energy goes Earth’sEarth’s atmosphere, it is calculated how many solar power watts can be generated when sunlight falls in a 1-meter square area. Hence its uint is Watt/meter square. At the top of Earth’sEarth’s atmosphere receives the power of 1.4 KW/msg. But this power reduces to 1 KW/msg. When it reaches the Earth’sEarth’s surface, the particles present in the atmosphere like water vapor, gas, and dust. Reflection of the light waves is also a reason for the reduction of solar power.
Utilization of Solar Energy:
Though you may think solar energy consumption begins after the invention of new electrical instruments like solar panels, solar energy consumption has been going on for ages. The trees and animals have been absorbing solar energy to function daily and still depends on sunlight directly or indirectly. As solar energy is available in high abundance in the Earth, and we can not absorb all of it naturally, many different techniques have been introduced and evolving to utilize this energy. Let’s discuss some of them-
1. Conversion of Solar Energy to Electrical Energy: Unlike metals and insulators, a semiconductor material exists where the current doesn’t flow until external energy is introduced. But whenever some external electric field, light radiation, or thermal energy is applied to its current starts flowing through a semiconductor, semiconductor behavior is the fundamental principle of solar energy to electrical energy conversion.
Using this principle, we can convert solar energy to electrical power from solar cells. Solar cells are made up of semiconductor materials like silicon. When sunlight falls into a solar cell, electron emission takes place, and further, we get the flow of electrons, which is nothing but electricity. But from one solar cell, we cannot get enough electricity for practical use. That is why many solar cells are connected in series to get a higher amount of electricity. Such an arrangement of solar cells is known as solar panels. This electrical energy can be further used in electrical appliances, electric vehicles, etc.
2. Conversion of Solar energy to Thermal energy: Solar energy converted to heat energy for various domestic or commercial applications like heating swimming pools produce domestic hot water, space heating, or supply other heat consumers. When solar radiation is incident on a solid body, it absorbs the solar radiation and emits the radiation in the form of heat; in this process, when light falls on a solid body, the body’s atoms start oscillating. This is the basic principle of solar to thermal conversion.
An energy collector or Sunlight collector is designed with mirror, lense, and heat exchangers to concentrate and absorb the solar energy (radiant energy from Sun). The fluids are passed through the sunlight collector to absorb the heat from the collector and get heated. This hot fluid can be transferred to a heat engine for the generation of electricity.
The above discussion was about the direct conversions of Solar energy to electrical and thermal energy. This Solar energy, which is converted into electrical energy, can be further converted into Mechanical energy. Electric vehicles, industrial machines, and robots, etc.
Storing of Solar Energy:
Storing of Solar energy comes into action because of two reasons- 1. Solar panels cannot generate any point during the night or on cloudy days.
When the generated energy by solar panels is higher than that of the required power.
Storing solar energy in the form of heat: The most straightforward way of storing solar energy is to convert it into thermal energy and utilize it for heating fluids like water. This heated fluid holds the heat energy for several times. A residential solar hot water system is the most outstanding example of storing solar energy in the form of heat energy.
Storing solar energy through battery: We are familiar with the fact that photovoltaic cells convert solar radiation to electrical power. This electrical energy can be stored in a shower in the form of chemical energy. When charging a rechargeable battery, it takes electrical energy and converts it to chemical energy through a chemical reaction. It converts the stored chemical energy to electrical energy through a chemical reaction at the time of discharge.
With the increasing popularity of solar energy and electric vehicles, the battery storage system has improved rapidly. Earlier lead-acid batteries or Nickel-Cadmium batteries were used to store energy, but in the early 1990’s a revolutionary battery was developed called Lithium-ion battery. Today, Li-ion is considered the most popular and promising battery. It is a high capacity(energy density), lightweight, low maintenance, and relatively low self-discharging battery. Earlier Li-ion was more elevated in cost, but its price decreased rapidly with these technologies’ improvement. During the past decades, its price has fallen immensely to about 90%. The main reason for falling in Li-ion price is due to the increasing popularity of electric vehicles worldwide. The Electric vehicle companies are deliberately trying to make the most efficient and cost-effective battery to minimize their cars’ overall cost.
With the evolution of human civilization, new technologies and inventions are being utilized to consume and store this solar energy. For example, we use solar panels or solar heaters, etc., But these techniques are not enough to utilize or destroy all the solar energy that reaches the Earth. The next line will astonish you when you know that each hour 430 quintillion Joules of energy hits the Earth. Can you imagine how much power is 430 quintillion Joules is?
It is nearly equal to the total amount of energy we all humans use over a year. Now you can imagine how much solar energy our Earth receives every hour. With our current technology, we can only utilize a tiny fraction of this vast energy source. So with the increasing energy demand, our next motive should be- 1.) to improve our present technology 2) we should find more efficient technology to increase energy consumption and utilization.