Clean energy includes: solar energy, wind energy, hydropower, etc.
1. Solar energy
Solar energy is a renewable energy source. It refers to the radiant thermal energy of the sun (see the three modes of propagation of thermal energy: radiation), and its main manifestation is often called solar rays. Nowadays, it is typically used to generate electricity or provide energy for water heaters. Since the birth of life on earth, it has relied primarily on thermal radiation energy provided by the sun. Since ancient times, humans have also known how to use sunlight to dry objects and use it as a method of making food, such as crafting. salt and dry the salted fish.
As fossil fuels decline, solar energy has become a significant part of consumptiontion of human energy and continues to develop. There are two ways to use solar energy: photothermal conversion and photoelectric conversion. Solar power generation is an emerging renewable energy source.
2. Wind energy
Wind energy is the kinetic energy generated by air flow. A converted form of solar energy. Due to the uneven heating of various parts of the earth's surface caused by solar radiation, the pressure distribution in the atmosphere is unbalanced. Under the action of the horizontal pressure gradient, the air moves in the horizontal direction to form wind. The total reserves of wind resources are very large, and the energy that can be technically developed in one year is approximately 5.3 x 10^13 kilowatt hours.
Wind energy is a renewable and clean energy with large reserves and wide distribution. However, its densityenergy is low (only 1/800 of the energy of water) and unstable. Under certain technical conditions, wind energy can be developed and used as an important energy source.
3. Water energy
Water energy is a kind of energy, clean energy and green energy. It refers to energy resources such as kinetic energy, potential energy and pressure energy of bodies of water. . Hydropower is a renewable energy source and is mainly used for hydroelectric power generation. Hydroelectricity converts the potential and kinetic energy of water into electrical energy. A plant that produces electricity from water is called a hydroelectric plant, or hydroelectric power station for short, also known as a hydroelectric power station. The advantages of hydroelectricity are its low cost, its continuously renewable production and its non-pollution. The disadvantage is that the distribution is strongly limited by natural conditions such as hydrology, climate and relief.
Advantages and disadvantages of solar energy:
1 Advantages
1 Universal
The sun . shines on the earth, there is no geographical restriction, no matter land or sea, no matter mountains or islands, it is everywhere, can be directly developed and used, easy to collect, and does not require mining nor transport.
2. Harmless
The development and use of solar energy will not pollute the environment. It is one of the cleanest sources of energy, which is extremely valuable today, when environmental pollution is becoming more and more significant. serious. .
2. Disadvantages
1. Dispersion
Although the total amount of solar radiation reaching the Earth's surface is large, theenergy flow density is very low. On average, near the Tropic of Cancer, when the weather is relatively clear in summer, the irradiance of solar radiation is greatest at noon, and the average solar energy received over an area of 1 square meter perpendicular to the direction of light solar is about 1000W if terminated; On average day and night throughout the year it is only about 200W.
In winter it is only about half, and on cloudy days it is usually only about 1/5. 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. Instability
Due to limitations of natural conditions such as day and night, season, geographic latitude and altitudee, as well as random factors such as clear, cloudy, cloudy, and rain, solar irradiation reaching a certain ground is both intermittent and extremely unstable, making large-scale application of the solar energy.
In order to make solar energy a continuous and stable energy source, and ultimately an alternative energy source capable of competing with conventional energy sources, the problem of solar energy storage energy must be well resolved, that is to say the energy of solar radiation. in clear weather it should be stored as much as possible. It can be used at night or on rainy days, but energy storage is also one of the weakest links in solar energy use.
Reference for the above content: Baidu Encyclopedia-Solar Energy
Reference for the above content: Baidu Encyclopedia-Water Energy