Solar Knowledge

Solar energy introduction
In the solar interior, the reaction of hydrogen atoms from "hydrogen" to "helium" is continuously releasing huge energy and continuously radiating energy to the cosmic space. This energy is solar energy. The average solar radiation intensity on the earth's orbit is 1367kw/m2, the circumference of the earth's equator is 40000km, so we can calculate that the energy of the earth can reach 173000TW, that is to say, the energy that the sun irradiates to the earth per second is equal to 5 million tons of coal. The fusion reaction inside the sun can last for billions of billions of years. It can be said that the sun is a huge, long and endless energy source, and human beings rely on these energies to survive.
Wind energy, hydro energy, ocean thermal energy, earth wave energy and tidal energy as well as some comes from the sun; even the earth's fossil fuels (such as coal, oil and natural gas) is fundamentally since ancient times the storage of solar energy down, so by including a broad range of solar energy is very righteous a large, narrow sense is limited to solar radiation can directly convert solar thermal and photovoltaic and photochemical.
Solar energy is both an energy and a renewable energy. It is rich in resources, can be used free of charge, without transportation, without any pollution to the environment. But there are two main disadvantages of solar energy. One is the low density of energy flow. The two is that its intensity cannot be maintained by various factors such as season, place, climate and so on. These two major shortcomings greatly limit the efficient use of solar energy.
The use of solar energy has a long history. In the Warring States period of more than two thousand years ago, China was aware of the use of steel four mirrors to focus the light of the sun, and to dry the agricultural and sideline products by using the solar energy. With the development of modern times, the utilization of solar energy is more and more extensive. It includes the photothermal utilization of solar energy, the photoelectric utilization of solar energy and the photochemical utilization of solar energy.

Photovoltaic power generation system
The solar power generation system consists of a solar cell group, a solar controller and a battery (Group). If the output power is AC 220V or 110V, the inverter is also required. The functions of each part are as follows:
Solar panels: solar panels are the core part of the solar power generation system and the most valuable part of the solar power generation system. The function is to convert the solar radiation to electrical energy, or to store it in the battery or push the load. The quality and cost of solar panels will directly determine the quality and cost of the whole system.
Solar controller: the function of the solar controller is to control the working state of the whole system, and play the role of overcharge and over discharge protection for the battery. In the place where the temperature difference is larger, the qualified controller should also have the function of temperature compensation. Other additional functions such as the light control switch and the time control switch should be the option of the controller.
Battery: usually lead acid battery, small micro system, also can use nickel hydrogen battery, nickel cadmium battery or lithium battery. The effect is to store the energy emitted by the solar panel in light of the light and release it when needed.
Inverter: in many situations, it is necessary to provide 220VAC, 110VAC AC power supply. The direct output of solar energy is generally 12VDC, 24VDC, 48VDC. In order to provide electrical energy to 220VAC electrical appliances, it is necessary to convert the direct current energy generated by the solar power system to the alternating current power, so we need to use the DC-AC inverter. On some occasions, when using various voltage loads, DC-DC inverters are also needed, such as converting the electric energy of 24VDC to the power of 5VDC.