New energy generally refers to the renewable energy developed and utilized on the basis of new technologies, including solar energy, biomass energy, wind energy, geothermal energy, wave energy, ocean current energy and tidal energy, as well as the thermal cycle between the ocean surface and the deep; In addition, there are hydrogen energy, biogas, alcohol, methanol, etc., and coal, oil, natural gas, water energy and other energy sources that have been widely used are called conventional energy sources. With the limitation of conventional energy and the increasingly prominent environmental problems, new energy with environmental protection and renewable characteristics has been paid more and more attention by all countries.

Conventional energy refers to energy that is technically mature and has been used on a large scale, while new energy usually refers to energy that has not been used on a large scale and is being actively researched and developed. Therefore, coal, oil, natural gas and large and medium-sized hydropower are regarded as conventional energy, and solar energy, wind energy, modern biomass energy, geothermal energy, ocean energy and hydrogen energy as new energy. With the progress of technology and the establishment of the concept of sustainable development, the industrial and domestic organic waste, which has been regarded as garbage in the past, has been re-recognized as a material for energy resource utilization and has been in-depth research and development and utilization. Therefore, the resource utilization of waste can also be regarded as a form of new energy technology.