七十年代初世界出现石油危机后，许多国家加大了新能源和可再生能源发展的投入和支持，近年来，严重的环境与生态问题日益突出，能源与环境的双重压力，更加引起各国政府对新能源和可再生能源的重视。1992年在联合国环境与发展会议上，各国政府签署了《里约宣言》，通过了《二 After the oil crisis in the world in the early 1970s, many countries have increased investment and support for the development of new and renewable energy. In recent years, serious environmental and ecological problems have become increasingly prominent, and the dual pressures of energy and the environment have caused even more governments around the world. The importance of new energy and renewable energy. At the United Nations Conference on Environment and Development in 1992, governments of all countries signed the Rio Declaration and adopted the "II.