TOKYO >> When Kozu island, 105 miles from Tokyo, was hit by a typhoon on Oct. 11, 2019, strong winds of more than 110 mph disrupted power for about six hours that night.

About 70 people evacuated to a community center on the island, which was equipped with solar panels and storage batteries. Inside, evacuees had lighting and fans to keep them cool.

“The night the storm cut the power … I was relieved to see the lights on,” said a 72-year-old resident who runs a guesthouse on the island.

The island once relied on diesel for power, but in 2017, solar power panels were installed at public facilities in anticipation of a weather event or disaster that would make it impossible to procure diesel off-island.

“It’s very useful because typhoons and power outages come to us as a set every year,” said a Kozu city official.

A survey conducted in 2019 by the Land, Infrastructure, Transport and Tourism Ministry showed that of 254 remote islands surveyed, 59 have installed renewable-energy generators on public facilities.

According to electric power companies, renewable energy is on the rise on remote islands, which are separated from power grids on the main islands of Hokkaido, Honshu, Shikoku and Kyushu.

Conversion to renewable energy has been particularly successful in Okinawa Electric Power’s service area, which spans many remote islands.

Central and local governments are also encouraging the introduction of renewable energy to remote islands.

In September, the Tokyo gov­ernment launched a program to subsidize 75% of the cost, up to 100 million yen (or more than $760,000), for residents on remote islands who install solar power on their homes.

The Environment Ministry and Okinawa’s prefectural government have encouraged businesses on remote islands as well and are subsidizing installation costs.

In 2024, Japan’s first large-scale tidal power project will begin in waters surrounding Naru island in the Goto Islands, the western area of Nagasaki prefecture, with assistance from the Environment Ministry.

A generator will be installed on the seafloor at a depth of more than 130 feet with a propeller more than 65 feet in diameter. The propeller will be rotated by the rising and falling tides to generate electricity, which will be supplied to surrounding islands.

According to Fukuoka-based Kyuden Mirai Energy Co., which is running the project, the system can generate electricity even if a typhoon hits the area directly. The company cited results from an experiment.

“We’d like to develop new businesses on other islands by utilizing the knowledge we have gained here,” said a company spokesperson.

On Kume island in Okinawa, testing of wave-generated power will be run this summer by a private company. Power is generated when ocean waves turn turbines inside floating devices. The company aims to have the system working in three years.

The challenge of implementing renewable-energy systems on remote islands is cost. The islands’ small cities require investment from private companies to manage installation and maintenance costs.

Izu Oshima island, south of central Tokyo, plans to begin experiments with offshore wind power in 2026, but it has yet to find a company willing to partner with it because of the expense.

“Without the support of a company, we’ll have no choice but to rethink our plan,” said a city official.

In a 2020 land ministry survey, many municipalities cited cost burdens as a hurdle to introducing renewable energy.

“For remote islands, it’s vital to have a stable, independent power source in case of isolation due to disasters … so the central government should encourage the municipalities with subsidies,” said Hikaru Hiranuma, a senior fellow at the Tokyo Foundation for Policy Research. “In addition, it’s important for local governments on remote islands to develop projects so that they can attract investment from companies.”