Resource-poor Japan is dependent on imports for 94% of its primary energy supply. Japan's energy supply structure is extremely vulnerable. Following the two oil crises in the 1970s, Japan has diversified its energy sources through increased use of nuclear energy, natural gas and coal, as well as the promotion of energy efficiency and conservation.
Despite these improvements, oil still accounts for about 40% of Japan’s primary energy supply, and more than 80% of imported oil comes from the politically unstable Middle East. Moreover, prospects for importing electricity from neighboring countries are very poor because Japan is an island nation. In addition, there is an urgent need for global warming countermeasures such as reduction of carbon dioxide emissions from the use of energy. To ensure Japan’s stable electricity supply, it is crucial to establish an optimal combination of power sources that can concurrently deliver energy security, economic efficiency, and environmental conservation, while placing top priority on safety.
For the future, it is important for Japan’s energy mix to continue to include a certain level of nuclear energy premised on ensuring safety, while maximizing the use of renewable energy and using a reasonable proportion of thermal power considering the stability of fuel supply.
The “Strategic Energy Plan” decided by the government in April 2014 also states that nuclear power is as important base load power source that can, strictly premised on safety, contribute to the stability of the supply and demand structure of energy.
In June 2015, a plan was announced to maintain the proportion of nuclear power at 20 to 22 percent in the energy mix in 2030.