Photo/Illutration Offshore wind turbines off Noshiro Port in Akita Prefecture on Dec. 9 (Kazuyoshi Sako)

NOSHIRO, Akita Prefecture--Japan’s first large-scale offshore wind farm has begun commercial operation here, fanning expectations for a new era of alternative energy.

Given that the nation is surrounded on all sides by the sea, offshore wind power offers a potential mainstay source of electricity supply. But to what extent it will grow and spread remains open to question.

Akita Offshore Wind Corp. operates the wind farm that went into commercial service off Noshiro Port in this northeastern city on Dec. 22.

The company’s second facility went online off Akita Port in the prefectural capital of Akita on Jan. 31.

Thirteen companies, including Marubeni Corp., Obayashi Corp. and Tohoku Electric Power Co., hold stakes in the Akita-based venture.

Combined, 33 wind turbines off Noshiro and Akita ports are capable of producing around 140 megawatts of electricity, enough to cover the demand of 130,000 general households.

In addition, government projects are under way off Akita and other prefectures under the Law on Promoting the Utilization of Sea Areas for the Development of Marine Renewable Energy Power Generation Facilities, which took effect in 2019.

The legislation allows general sea areas not administered under specific laws or regulations to be put to exclusive use for a maximum of 30 years.

Three wind farms with a combined output capacity of 1.7 gigawatts, with two of them planned off Akita Prefecture and the other off Chiba Prefecture, represent the first batch of those projects to go ahead.

An open competition process got under way Dec. 28 for a second batch comprising four wind farms with a combined output capacity of 1.8 gigawatts. Two facilities are planned off Akita Prefecture, and one each off Niigata and Nagasaki prefectures.

The area off Akita Prefecture is among Japan’s prime locations suited to host offshore wind farms.

Figures from the Environment Ministry and other parties show that annual average wind speeds range roughly between 23.4 kph and 30.6 kph off Akita Prefecture, in many places exceeding 25.2 kph, one of the thresholds above which a sea area is deemed suitable for offshore wind.

Wind directions there are also relatively stable.

“There are hopes the area, with its favorable wind conditions, will serve as a pioneering model for offshore wind ventures,” said Shigehito Nakamura, managing director of the Japan Wind Power Association.

Akita Prefecture’s “pioneering” status has attracted interest from companies eager to find business opportunities.

Consortiums centered on Mitsubishi Corp. were the successful bidders for the first batch of the government’s offshore wind projects. The trading house in November established a branch office in Akita, one of the first it had opened in Japan in 35 years.

Shipping giant Nippon Yusen KK also set up a branch office in Akita in April, its first domestic foray in 59 years, in hopes winds farms will spur demand for sea transport for research and other purposes.


Offshore wind turbines off Akita Port in Akita Prefecture on Dec. 9 (Kazuyoshi Sako)

Industry ministry figures show that renewable energy sources accounted for 20.3 percent of Japan’s total power supply in fiscal 2021.

The largest slice, 8.3 percent, was taken up by photovoltaic power. Wind power, including onshore facilities, accounted for a meager 0.9 percent.

Japan already tops other major countries in the output capacity of photovoltaic power per unit of national land area. Solar farms occupy most of the available large-scale land plots suited for the purpose.

The government envisages green energy sources accounting for 36 to 38 percent of Japan’s electricity mix in fiscal 2030 and further raising the ratio in subsequent years, which calls for an increase in offshore wind power generation.

According to the Global Wind Energy Council, a worldwide industry group, offshore facilities were developed for producing 21.1 gigawatts of wind power in 2021, up three times year on year. Offshore wind projects are increasing particularly in Europe and China.

Japan is falling behind, but the government hopes to add up to 45 gigawatts in offshore wind power generation capacity, equivalent to 45 nuclear power reactors, by 2040.

Costs remain the key challenge to the introduction of more offshore wind facilities.

Successful bids by the Mitsubishi-led consortiums in the first batch of government projects in general sea areas set the selling prices of electric power at between 11.99 yen and 16.49 yen per kilowatt-hour, about half or less than half of the cap of 29 yen set by the government in its public tenders.

This compares with less than the equivalent of 10 yen per kilowatt-hour at a number of offshore wind projects in Europe.

In Japan, expenses for spreading the use of renewables are being added to electricity rates, and standard households already shoulder more than 10,000 yen a year for that purpose. Cost cuts are crucial, not least to reduce that burden.

The installation of wind turbine foundations on the seabed off Akita and Noshiro ports in summer 2021 generated so much noise that residents in nearby areas complained.

There are also strong concerns about the impact the wind farms could have on the fishing industry.

“To dispel concerns among fishermen, authorities need to listen to their views in conducting impact assessments,” said Masao Miura, a chief researcher with the Marine Ecology Research Institute’s Marine Biology Group in Chiba Prefecture outside Tokyo.

Developing related industries in Japan will also be key to future cost reductions. For the AOW projects, only about 20 percent of all the procurement came from domestic suppliers.

In Japan, where there are few gently shelving shallow beaches, floating offshore wind farms are expected to come into demand.

Wind turbines for these facilities are installed on structures floating at sea, while turbine foundations for conventional wind farms are embedded in the seafloor.

Japan has the potential for turning things around by taking the lead in floating offshore wind farms, which are still under development in Europe.

“The government should present an outlook for when and where there could be offshore wind projects and how big they could be,” said Chihiro Terasawa of the Mitsubishi Research Institute. “Making the market visible would make it easier for businesses, both in Japan and abroad, to come on board.”

(This article was written by Rei Inoue, Hokuto Matsumura, Junichiro Nagasaki and Shimpei Doi.)