Renewable energy refers to energy that can be continually regenerated and used sustainably in nature. It has the characteristics of inexhaustibility and inexhaustibility. It mainly includes solar energy, wind energy, hydropower, biomass energy, geothermal energy and ocean can wait. . Renewable energy is harmless or of little harm to the environment, and its resources are widely distributed and suitable for local development and use.
● Solar energy
Solar energy is energy coming from celestial bodies outside the Earth. Most of the energy needed by humans comes directly or indirectly from the sun. These are various plants that convert solar energy into chemical energy through photosynthesis and store it in the plant body. There are two ways to use solar energy: photothermal conversion andphotoelectric conversion. Solar energy is an emerging renewable energy source.
• Wind energy
Wind energy is the kinetic energy generated by the movement of large quantities of air across the Earth's surface. Due to the different temperature changes and different water vapor content in the air after the ground is irradiated by the sun, the air pressure in different places is different in the horizontal direction, the air high pressure flows to areas of low pressure, resulting in temperature variations. is the formation of the wind. Wind energy resources are determined by wind energy density and the annual number of accumulated hours of available wind energy. Wind power density is the wind power available per unit wind area and is proportional to the cube of wind speed and air density.
● Water energy
EnergyWater energy is clean energy and green energy. It refers to energy resources such as kinetic energy, potential energy and pressure energy of water masses. Broad water energy resources include river water energy, tidal water energy, wave energy, ocean current energy and other energy resources. Water energy resources in the narrow sense refers to river water energy resources, which are conventional energy and primary energy; . The relatively mature water power that is easiest for people to develop and use at present is also river power. Hydropower is mainly used for the production of hydroelectric power. Its advantages are low cost, continuous regeneration and no pollution. The disadvantage is that the distribution is strongly limitede by natural conditions such as hydrology, climate and relief. Water is easily polluted and easily affected by terrain, climate and other factors.
● Biomass energy
Biomass energy is the energetic form of solar energy stored in biomass in the form of chemical energy, i.e. - say an energy with biomass as a vector. For the oil industry, biodiesel is currently the biggest concern. It is a type of biomass energy, which refers to a renewable fuel that can replace diesel produced by a transesterification process using oil crops, wild oil plants and aquatic plant oils, as well as animal oils, used catering oils, etc. as raw material. oil. In addition, fuel ethanol is also receiving increasing attention.
● Geothermal energy
Energy gEothermal is the thermal energy contained in rocks and fluids within the earth. It is the energy source that powers all thermal processes within the earth, and its thermal energy is transported outward in the form of conduction. The temperature inside the earth reaches 7,000°C. This enormous thermal energy flows through the flow of groundwater and rising lava to the crust 1 to 5 kilometers above the ground, and the heat can be transferred to nearby locations. the ground. Hot lava heats nearby groundwater. This heated water will eventually seep out of the ground. The simplest and most cost-effective way to use geothermal energy is to directly access and extract energy from these heat sources.
• Ocean energy
Ocean energy refers to renewable energy attached to seawater. The ocean receives, stores and emits energythrough various physical processes. These energies exist in the ocean in the form of tides, waves, temperature differences, salinity gradients, ocean currents, etc. The area of the Earth is about 510 million square kilometers, of which the land area is 149 million square kilometers, or 29%; the surface area of the oceans reaches 361 million square kilometers, or 71%. In terms of sea level, the average altitude of all land is around 840 meters, while the average depth of the ocean is 380 meters. The total volume of sea water reaches 1.37 billion cubic kilometers. The endless sea not only provides humans with navigation, water sources, and rich mineral deposits, but it also contains enormous energy. It stores solar energy and wind energy derived in sea water in the form of thermal energy, mechanical energy, etc., which is not lostas easily as on land and in the air.