Under the dual pressure of energy crisis and environmental degradation, distributed power generation, as a supplement to the traditional power supply method, is gradually being widely used and playing an increasingly important role.
The United States is one of the first countries in the world to study distributed power generation. Since the 1970s, distributed power generation has developed rapidly from small-scale cogeneration systems to the widely used combined cooling, heating and power generation systems. In order to promote the development of distributed power generation, the United States has formulated many effective policies. In 1978, the United States promulgated the “Public Equipment Management Policy Act” and related tax incentives, which promoted the rapid development of cogeneration and improved energy efficiency. In 2001, the United States promulgated the “Draft Standard on the Interconnection of Distributed Power Sources and Power Systems”, which officially allowed distributed power sources to be connected to the grid, and users could sell surplus power to the large power grid: From 2007 to 2009, the United States promulgated a series of new energy policies to vigorously develop renewable energy. In 2008, the installed capacity of wind power in the United States reached the first place in the world. In summary, distributed power generation in the United States has mainly gone through three different stages of development. That is, from independent, small-scale cogeneration to distributed power generation systems that can be connected to the grid to sell electricity, to distributed power systems that are combined with renewable energy.
The United States is rich in oil and gas resources and has a wide distribution of pipelines. The distributed power generation projects are mainly natural gas cogeneration. As of 2016, the United States has built more than 6,000 distributed energy stations, and the distributed power market has reached more than one billion U.S. dollars. It is planned that by 2020, its total installed capacity of distributed power generation will reach 187 million kW, accounting for 29% of the total installed capacity. As the U.S. power industry has experienced several major power outages, the development of distributed power generation in the U.S. pays special attention to the safety and reliability of power supply.
Japan is a highly developed industrialized country, and its energy demand is huge. At the same time, Japan is an extremely resource-scarce country, and its own energy supply is seriously inadequate. The energy required for power generation mainly depends on imports. Therefore, Japan attaches great importance to the development of renewable resources. It has been using renewable energy represented by solar energy and wind energy very early to promote solar photovoltaic power generation and wind power generation technologies. At the same time, Japan also pays special attention to improving energy efficiency and has promulgated a series of related policies. In 1974, Japan introduced a subsidy policy for residential rooftop photovoltaic power generation systems; in 1986, Japan issued the “Grid-connected Technical Requirements Guidelines”, which provided a basis for the grid-connected distributed power generation; in 1995, Japan revised the “Electricity Law” and “Grid-connected Technical Requirements Guidelines” to allow distributed power owners to sell excess power to power supply companies and enjoy government subsidies, financing and other preferential policies; from 2005 to 2008, Japan formulated the Kyoto Protocol target plan to establish the effective role of combined heat and power. Distributed combined heat and power was identified as a technological innovation of high energy utilization, and it was vigorously promoted in hospitals, hotels, steel, petrochemicals and other fields; in 2010, Japan put forward the policy of building a low-carbon society and issued a plan to promote the introduction of natural gas cogeneration systems. After the major earthquake in Tokyo in 2011, more attention was paid to the development of distributed power sources. These policies have greatly promoted the development of distributed power generation in Japan. As of 2015, Japan’s distributed energy power generation accounted for 14%.