New solar energy has obvious characteristics compared to fossil fuels such as oil, coal, natural gas and nuclear energy.
1? Abundant resources
Solar energy is the most abundant energy source that humans can use. According to the theory of stellar evolution, the Sun can radiate energy at its current power for almost 10 billion more years. Experts deduce that over the past billion years, the sun has only consumed 2% of its own energy, so this will not change significantly over the next billion years. So we can say that the sun can be used permanently. Energy is inexhaustible and inexhaustible. The energy it sends to the ground for 15 minutes is enough for the entire world to use for a year. The energy of solar radiation that reaches the Earth's surface each yearborn is approximately equivalent to 130,000 billion tons of standard coal. Its total quantity is the largest. the energy that can be developed in the world today. For example, if we compare the different energy sources currently used each year by humans around the world to the energy emitted during the explosion of a grenade, then the energy of solar radiation that reaches the surface of the earth each year and can be used by humans is equivalent. to a hydrogen bomb. The amount of energy released during the explosion varies considerably.
2? Clean and pollution-free
The development and use of solar energy will not pollute the environment. When using solar energy, it will not emit any substances that have a negative impact. on the environment. It is the cleanest source of energy, in today's world where environmental pollution is becoming more and moreserious, it is extremely valuable and presents an incomparable advantage compared to any other source of energy.
3? Widely distributed
The sun shines on the earth, no matter the land or the sea, no matter the mountains or the islands, there is bright sunshine, and it does not require transportation and is easy to get. Areas between 50 and 60 degrees north and south latitude, with annual daylight hours of 1,600 to 2,400 hours, are generally thought to be rich in solar energy that can be used provided that an initial investment is made. made to build solar energy. device in use, the energy will continue to flow on its own. Delivered to your door.
1? Low intensity
Although the solar energy reaching the upper limit of the earth's atmosphere and reaching the earth's surface is very huge, its intensity is not high. This energy is too scattered. A disadvantagest that as a source of energy, its density is too low. On average, near the Tropic of Cancer, when the weather is relatively clear in summer, the irradiation of solar radiation is greatest at noon, and the average solar energy received in an area of 1 square meter perpendicular to the direction of light from the sun is only about 1,000 watts if the average day and night throughout the year is only about 200 watts; In winter it only reaches half, and in cloudy weather it is only about a fifth. This energy flow density is very low. Therefore, when using solar energy, if we want to obtain a certain conversion power, we often need a set of collection and conversion equipment with a considerable area, which is expensive.
2? Discontinuity
The greatest weakness of solar energy is its discontinuity. The alternation of day and night causes interruptionsptions of solar radiation. On average, across most of the planet, almost half of the year is plunged into darkness; the remaining half of the year is spent in darkness. What is the weather like? It is already very difficult to use solar energy on cloudy and rainy days, but it is impossible to use solar energy at night, which seriously limits the application of solar energy.
3? Uncertain
Due to limitations of natural conditions such as day and night, season, geographic latitude and altitude, as well as random factors such as clear, cloudy, cloudy and rainy weather , arriving at a certain place The solar irradiation on the ground is neither continuous nor stable, which makes the large-scale development and utilization of solar energy more difficult.
At the same place, on the same day, the intensity of solar radiation at sunrise and sunset is much lower than that aroundnoon and in the same place, in different seasons, the intensity of solar radiation in summer is much lower; higher than in winter. The main reason is that due to the different altitude angles of the sun, the angles of incidence relative to the same horizontal plane are naturally different. The greater the angle of solar altitude, or the smaller the angle of incidence of solar radiation, the more solar energy is received in the same horizontal plane on the ground, conversely, the greater the angle of solar radiation. solar altitude is small, or the larger the angle of incidence of solar radiation, the greater the angle of solar altitude, or the smaller the angle of incidence of solar radiation, the more solar energy is received in the same horizontal plane on the ground. the more solar energy is received in the same horizontal plane on the ground, the less solar energy is received. Everyone must have had this experience when drying clothes: when the flat surface of the garmentt to dry is facing the solar radiation, it dries the fastest, but when it is sideways facing the solar radiation, it dries more slowly.
In order to make solar energy a continuous and stable energy source, and thus to make it an alternative energy source that can compete with conventional energy sources, the problem of storage energy should be well resolved, that is, solar energy radiation on clear days should be It can be stored as much as possible so that it can be used at night or on rainy days, but currently the Energy storage is also one of the weakest links in solar energy use.
4? High cost
The current level of development of solar energy use is theoretically feasible and technically mature. However, some solar energy utilization devices have high cost and low efficiency. On the born sidenegative, overall the economy cannot compete with conventional energy sources. For a long time, the development of the use of solar energy will be limited mainly by economic costs.