The sun or the heart of the solar system, which is the star closest to Earth, is estimated at 26,000 light-years, and the age of this star is estimated at 4.5 billion years. The huge gravity in the sun is responsible for the stability of the solar system so that all the components of the solar system from the large planets and to the small parts are fixed each In its orbit.
Solar energy, or what is called solar radiation, (in English: solar energy), is the energy emitted from the sun’s rays mainly in the form of heat and light, and it is the product of nuclear reactions inside the star closest to us, which is the sun, and this energy has great importance in the earth and the living things that exist On its surface, the amount of this energy produced far exceeds the current energy requirements in the world in general, and if it is harnessed and exploited appropriately it may meet all future energy needs.
The importance of solar energy
The importance of solar energy lies in the beginning because the sun’s rays have facilitated the processes of evolution in living organisms, which are responsible for photosynthesis processes in plants to produce food and biomass, in addition to the role of these rays in hydropower and wind energy. Also, there is a great importance of solar energy in the Cultivation of the land, production, and growth of crops and drying of food to prevent it from spoilage, in addition to using greenhouses to raise the heat.  In addition, solar energy is responsible for the so-called group of renewable energy sources and the most important of which, and it is noticeable that the importance of solar energy is increasing as a source of renewable energy sources. It does not decrease and has an unpolluted character, at a time when the levels of fossil fuels, oil, and coal, in addition to natural gas, have decreased significantly.
Applications of the exploitation of solar energy
There are a large number of applications on the exploitation of solar energy in our lives, including ancient and modern ones that keep pace with modern technology, and the most famous of them are:
- directing homes and their windows towards the sun’s rays, so that light and heat are used in homes, in addition to choosing the type of materials in the building so that they are able to absorb and store heat.
- Agriculture in greenhouses or thermal homes, where you convert the sun’s rays into thermal energy, which contributed to facilitating the process of planting and growing plants in the off-season.
- Cooking using the solar cooker, which is a box in which the sun’s rays are collected and their heat used in cooking food, which was made for the first time in 1767 by the Swiss physicist (Horace de Saussure).
- Instrument sterilization, it was reported that in some areas a modified and specialized solar cooker was used for the purpose of sterilizing medical instruments in clinics.
- Solar heating, which takes advantage of solar rays and uses them to heat water in homes and buildings through a specialized system of solar panels installed on the roofs of buildings.
- Water sterilization, studies have stated that when water is exposed for several hours to sunlight, the presence of bacteria, viruses, and parasites in it reduces, as there are more than 2 million people in developing countries who use this method daily.
The process of generating electricity from solar energy and the two most popular methods of generating it:
- Solar cells, which convert the sun’s rays into electricity directly, the amount of energy generated in a single cell is relatively small, so it is necessary to collect a large number of cells together, such as those in solar panels on the roofs of buildings to generate sufficient energy, and this type of cells was used in satellites and communication networks.
- At the space level, and at the ground level, these cells have been used in calculators, watches, homes, commercial buildings, and even stadiums. Kaohsiung World Stadium in Taiwan was built in 2009 and 8,800 solar panels were used on the top of the stadium.
- Solar concentrating technology, here uses the sun’s heat instead of rays as in solar cells, so that there is a group of lenses or mirrors that focus the light from the sun in the form of a beam that is used to make a water heater start working, which in turn produces steam that stimulates turbines to start producing electricity.
Advantages of solar electricity
There are many advantages and advantages that solar energy and the electricity generated from it are distinguished, the most important of which are:
- The cost of producing and generating energy is low.
- Ensure the disposal of high electricity prices for homeowners.
- A renewable and durable energy source that NASA estimates that the sun will continue to radiate for 6.5 billion years.
- It is considered environmentally friendly, as it does not cause pollution.
- Radiation is widely available geographically.
- Reducing the cost of consumed electricity (homeowners can sell their surplus after energy is produced).
- The use of collective solar panels reduces and overcomes the problems of individual installation and installation for each home.
- Few moving parts, hence less need for maintenance compared to the energy generated from wind.
- Material support from governments and countries.
The most popular home use of solar energy
After starting to use solar energy applications, and with its compatibility with modern technology, it has been used in homes in several forms, the most famous of which are:
- Sun-based outdoor ventilation fans.
- Solar heating for swimming pools using a special solar heating system.
- Solar heating systems for domestic water.
- Solar heating systems for home heating.
- Home water pumps by having small solar panels.
- The batteries are charged by solar energy.
- Supplying the house with electricity through solar panels. Cooking using a solar cooker based on sunlight and solar energy.
- External lighting, such as the lighting in the garden and places far from home electricity, so solar panels can be used to supply them with electricity.
Solar energy storage methods
Solar energy can be stored in several ways, including:
- storing it in dedicated batteries or large capacitors, and then using it at night or when the clouds are blocking the sun.
- Using sunlight to produce fuel, for example, some electrochemical cells use solar energy to split the water molecule into hydrogen and oxygen and thus store them in the form of fuel (gas), and when needed, these two gases are combined again to produce electricity by a device called a fuel cell.
- The concentrated thermal energy from the sun’s rays can be stored in dissolved salt or brine at a high temperature, and when electricity is needed, heat is transferred from the dissolved salt to the water by means of a heat-changing device to generate steam that activates turbines designed to produce electricity.