Japan is planning to expand offshore wind power generation beyond its territorial waters to its exclusive economic zone, in a push to achieve carbon neutrality and ensure energy security amid Russia's war in Ukraine.

A panel of experts who looked into the feasibility of building wind power facilities in the EEZ has recently concluded that such construction is possible as long as Japan backs it with domestic law. Based on the view, the government is planning to prepare necessary legislation or a legal revision, officials said, just as the country is set to update its marine strategy around May.

Russia's war in Ukraine has fueled energy supply concerns globally and heightened the need to diversify energy sources.

A floating wind power turbine off Nagasaki Prefecture, southwestern Japan, is seen in this file photo taken in November 2018. (Kyodo)

Resource-scarce Japan has relied heavily on thermal power but the rising global momentum toward decarbonization means it needs to secure more energy from alternative sources like renewables, which account for only a small portion of the nation's energy mix.

Some European nations, including Britain, Belgium and the Netherlands, already have offshore wind farms in their EEZs. China and South Korea are also stepping up offshore wind power generation.

"We have the responsibility of taking steps in line with global efforts toward carbon neutrality," Prime Minister Fumio Kishida said in December as he received proposals. "We will make better use of marine resources to realize a decarbonized society by expanding offshore wind power to the EEZ."

Wind electricity generation achieved the highest growth among renewable sources in 2021 but annual output capacity needs to increase to achieve carbon neutrality in 2050, according to the International Energy Agency, which noted that further cost reductions are required for offshore wind power.

The ruling Liberal Democratic Party has been urging the government to come up with a strategy to make better use of the sea, which is critical for transport, resource development and national security.

Japan's biggest business lobby Keidanren has also stressed the need for the island nation that has the world's sixth largest marine area, to boost its maritime competitiveness. The Japan Business Federation, as the body is formally known, singled out offshore wind power as a key area that requires support to build necessary supply chains and develop technology that will help curb costs.

Japan already has offshore wind turbines fixed to the seabed within its territorial waters. In the EEZ extending up to 200 nautical miles, or around 370 kilometers, from the coastal baseline, where water is deep, floating wind turbines are seen as suitable.

The recent go-ahead by the government panel is a step forward in Japan's future installation of offshore wind turbines in the EEZ but experts say it will likely take years for them to become operational.

By 2040, Japan is aiming to boost offshore wind power generation to 30 to 45 gigawatts, equivalent to roughly 45 nuclear reactors.

In the broader energy mix, the government aims for renewables to account for 36 to 38 percent in fiscal 2030, doubling from fiscal 2019. Japan will get around 20 percent each from nuclear power and coal.

The offshore wind power push could become a sensitive issue when national security comes into the equation. The government will need to decide where in the EEZ to allow such equipment to be installed and consult with relevant parties.

Under the United Nations Convention on the Law of the Sea, the coastal state has "sovereign rights" when "exploring, exploiting, conserving and managing the natural resources" in the EEZ.

The state can set safety zones around installations and structures like wind turbines but freedom of navigation should be ensured for all states. The law also calls for "due regard" to the rights of other states.

"When it comes to 'due regard,' it's important to ensure the freedom of navigation for other states. Before that, what is more important is to decide what Japan intends to do," the report by the government panel said.