All the energy used is renewable. In addition to nuclear energy, tidal energy and geothermal energy, the basic energy for human activities mainly comes from sunlight. For example, bioenergy and fossil energy such as coal, oil and natural gas are mainly stored by absorbing solar energy through photosynthesis of plants. Other things like wind power, water power, ocean currents, and so on, are also the result of sunlight heating the air and water on the earth.
Water can not only be directly used by human beings, it is also the carrier of energy. The solar energy drives the water cycle on the earth to keep it going. The flow of surface water is an important link. In areas with large drop and large flow, there are abundant water energy resources. The mill is a good example of using water energy. Hydropower is an important modern energy, especially in China, Canada and other countries full of rivers.
Wind energy refers to the energy loaded by wind. The size of wind energy depends on the wind speed and air density. Some islands in the north and southeast coastal areas of China are rich in wind energy resources. According to the relevant data of the national meteorological department, China's land exploitable wind energy resources are 253 million kilowatts, mainly distributed in the southeast coast and islands, Xinjiang, Gansu, Inner Mongolia and Northeast China. In addition, China's offshore wind energy resources are also very rich. It is preliminarily estimated that it is about three times of the land wind energy resources. The total amount of resources that can be developed and utilized is 750 million kilowatts.  people have been using wind for hundreds of years. Such as windmills, sailboats, etc.
Solar energy refers to the energy carried by the sun. Its measurement is generally based on the total amount of radiation from the sun to the ground, including the sum of the direct radiation from the sun and the scattered radiation from the sky. The utilization of solar energy mainly includes: photovoltaic (solar cell) power generation system, which directly converts solar energy into electrical energy; solar energy heating system, which generates electrical energy by using the heat energy of the sun; passive solar house; solar water heating system; solar heating and cooling. Since ancient times, people have known to dry things in the sun, and as a way to preserve food, such as salt and salted fish.
Geothermal energy is the heat energy stored in underground rocks and fluids. It can be used to generate electricity, or to heat and cool buildings. Human beings began to use geothermal energy for a long time, such as bathing in hot springs, medical treatment, heating with underground hot water, building crop greenhouses, aquaculture and drying grains. However, the real understanding of geothermal resources and large-scale development and utilization began in the middle of the 20th century, and the modern generation mainly uses geothermal energy to generate electricity.
Ocean energy is a general term of tidal energy, wave energy, temperature difference energy, salt difference energy and current energy. The ocean receives, stores and emits energy through various physical processes. These energy exist in the ocean in the form of tide, wave, temperature difference and current. For example, the form of tide comes from the attraction of the moon and the sun to the earth. The energy loaded between the rising tide and the falling tide is called tidal energy; the tide and the wind form ocean waves, which generate wave energy; the sun shines on the surface of the ocean, which forms a temperature difference between the upper part and the bottom of the ocean, thus forming a temperature difference energy. All these forms of ocean energy can be used to generate electricity.
Biomass energy refers to the organic matter that can be used as fuel or industrial raw material, living or just dying. Biomass energy is most commonly found in biofuels produced by growing plants, or in animals or plants used to produce fibers, chemicals, and heat. Many plants are used to produce biomass energy, including straw, awn grass, switchgrass, hemp, corn, poplar, willow, sugarcane and algal biomass fuel, biogas (methane), cattle manure, etc.