Close to a small fishing port in southwestern Japan, the slim white turbines of the country’s first commercial-scale floating wind farm glimmer offshore, months before a key project in Tokyo’s green-energy strategy begins.

Still heavily reliant on imported fossil fuels, Japan has declared offshore wind energy a “trump card” in its drive to make renewables its top power source by 2040, and reach carbon neutrality a decade later.

That’s despite rising project costs and fears over inadequate infrastructure to produce turbines en masse.

Floating turbines are particularly well suited to Japan as its deep coastal waters make fixing them to seabeds tricky, while the country is also prone to natural disasters.

“Floating structures are relatively stable even in the case of earthquakes or typhoons,” said Kei Ushigami, head of marine renewable energy for construction company Toda, a key player in the project.

The eight turbines—sitting five kilometers (three miles) off the coast of the Goto Islands in waters up to 140 meters deep—will officially start turning in January.

It’s hoped they’ll aid the archipelago in reaching ambitious new targets laid out this year that should see wind’s contribution to the energy mix soar to between 4% and 8% by 2040—up from around 1% today.

But it’s a long, hard road ahead for resource-scarce Japan—the world’s fifth-largest carbon dioxide emitter—to wean itself off fossil fuels.

In 2024, 65% of its electricity needs were met by coal and hydrocarbon-powered thermal plants, while just over a quarter came from renewables, according to Japan’s Institute for Sustainable Energy Policies.

Herculean task

Costs are also rising sharply, and at the end of August Japanese conglomerate Mitsubishi pulled out of three key wind power projects deemed no longer profitable.

Other project operators have asked for better support from the government.

“It is important for the government to address shortcomings in the current bidding system, which failed to anticipate rapid global inflation after bids were awarded,” said Yoko Mulholland from the think tank E3G.

The streamlining of regulatory processes and easing construction restrictions would “shorten lead times and also lower capital expenditure”, she told AFP.

Hidenori Yonekura, from the New Energy and Industrial Technology Development Organization, sees the nascent floating wind energy as a path to eventually lower costs, by installing more turbines in Japan’s vast Exclusive Economic Zone of 4.5 million square kilometers.

The task, however, appears Herculean: to meet the 2040 wind target, around 200 15-megawatt turbines a year need to go up.

But “the infrastructure is not yet in place”, warned Yonekura. “Japan lacks turbine manufacturers and large production sites.”

Fishers’ livelihoods

Construction companies also face technical challenges with these still-novel systems: defects discovered in the floating structure of a wind turbine at Goto meant Toda had to make replacements, delaying the project by two years.

Coexistence with local industries, especially fishing, is also crucial.

Toda said it had conducted an environmental assessment and found a pilot project had “no negative impact on fish”.

Fishermen also receive part of the revenue from electricity sales and some of the property taxes generated by the project, while some have been hired to monitor the construction site with their vessels.

But according to Takuya Eashiro, head of the Fukue fishing cooperative in Goto, the wind project was imposed “from the top” and presented as “a done deal”.

Nevertheless, “fishermen understand the importance of such a project for Japan”, he said.

The National Federation of Fisheries Co-operative Associations protested to the government after Mitsubishi withdrew, reminding them that fishermen had worked with these projects, hoping for positive economic impacts.

As fishing becomes less viable owing to warming sea temperatures, “some hope their children or grandchildren will find jobs in wind turbine maintenance”, said Eashiro.

© 2025 AFP

A team of researchers at DTU may have cracked one of the toughest nuts in sustainable energy: how to make fuel cells light and powerful enough for aerospace applications.

An interdisciplinary collaboration between DTU Energy and DTU Construct has developed a radical redesign of the so-called solid oxide cells (or SOCs), using 3D printing and gyroid geometry. This intricate structure is mathematically optimized to improve surface area in a given volume and is employed both by engineers for heat exchangers and by nature in structures such as butterfly wings.

Gyroidal architecture is structurally robust, has a large surface area, and is lightweight. For the first time, DTU scientists have shown how to use the gyroid to make electrochemical conversion devices such as SOCs.

To power a commercial airplane today, you need jet fuel. If you retrofit a regular jet, replacing its 70 tons of fuel with Li-ion batteries of similar capacity, its weight would be 3,500 tons. And so it wouldn’t take off.

The same has been true for fuel cells, mostly confined to flat, heavy stacks that rely on metal parts for sealing and connectivity. So, those are heavy, too. Metal components make up more than 75% of a fuel cell system’s weight, severely limiting their mobility and consequently, their usefulness in, for example, aerospace applications.

Sustainable flight?

In a new paper published in Nature Energy, DTU scientists may have flipped the script. Professor Vincenzo Esposito from DTU Energy, Senior Researcher Venkata Karthik Nadimpalli from DTU Construct, and several colleagues from both departments have designed a new fuel cell that is fully ceramic and is built by 3D printing. The printed structure is known as a triply periodic minimal surface (TPMS) and is mathematically optimized for maximum surface and minimum weight.

Their fuel cell—they call it a Monolithic Gyroidal Solid Oxide Cell or The Monolith for short—delivers more than one watt per gram. Not only is this a first, but it also broadens the field of possible fuel cell applications significantly, explains Nadimpalli, corresponding author of the study.

“Currently, using electricity-based energy conversion, such as batteries and fuel cells, doesn’t make sense for aerospace applications. But our new fuel cell design changes that. It’s the first to demonstrate the Watts to gram ratio—or specific power—needed for aerospace, while using a sustainable, green technology,” he says.

Extreme resilience

Fuel cells are nothing new, and their impact is evident in several sectors. While perhaps most visibly in hydrogen cars, they are, for example, also used as power supplies for hospitals and data centers, in ships, and as storage to stabilize renewable energy systems. Their ability to switch between power-generating and power-storing modes (electrolysis) makes them highly versatile in several applications.

There are many other reasons why the new fuel cells from the team of DTU scientists may be a game-changer. Apart from the weight being brought down significantly, the system allows gases to flow efficiently through the cell, improves heat distribution, and enhances mechanical stability. Switching to electrolysis mode, they produced hydrogen at nearly 10 times the rate of conventional designs.

“We also tested the system in extreme conditions, including temperature swings of 100°C, and repeatedly switched between fuel cell and electrolysis modes. The fuel cells held up impressively, showing no signs of structural failure or layers separating,” says Esposito, corresponding author.

The researchers explain that this kind of resilience is vital for space missions like NASA’s Mars Oxygen ISRU Experiment (MOXIE), which aims to produce oxygen from Mars’ carbon-dioxide-rich atmosphere.

This mission currently relies on bulky stacks weighing more than 6 tons. The new design could deliver a similar performance at 800 kg, which would significantly lower the costs of launching the equipment up there.

What makes this design especially compelling is not only its performance but also how it’s made, explains Nadimpalli, “While conventional SOC stacks require dozens of manufacturing steps and rely on multiple materials that degrade over time, our monolithic ceramic design is produced in just five steps, where we eliminate the metal and avoid fragile seals.

“Still, I believe that we can improve the system further using thinner electrolytes, cheaper current collectors, like silver or nickel instead of platinum, and even more compact designs.”

Microscopic turbulence in plasma can trigger macroscopic structural changes. In complex physical systems, such cross-scale interactions—between different spatial and temporal scales—are known as multiscale coupling. To the best of their knowledge, Prof. Yong-Seok Hwang’s team, together with the Asia Pacific Center for Theoretical Physics, has now experimentally proven this phenomenon for the first time.

The work is published in the journal Nature.

The breakthrough resolves a long-standing puzzle in plasma physics, with implications for both fusion energy development and the study of astrophysical plasmas.

Seoul National University College of Engineering announced that a joint research team led by Prof. Yong-Seok Hwang from the Department of Nuclear Engineering, in collaboration with the Asia Pacific Center for Theoretical Physics (APCTP), has experimentally demonstrated the phenomenon of multiscale coupling in plasma—a long-standing puzzle in plasma physics—through the integration of fusion experiments and astrophysical plasma theory.

Initiated under the proposal of Prof. Hwang, who holds appointments in the Department of Nuclear Engineering and the Department of Energy Systems Engineering, the study was conducted solely by three Korean researchers.

The team included Dr. Jong Yoon Park, BK Assistant Professor at SNU and first author of the paper, and Dr. Young Dae Yoon, theoretical physicist at APCTP and corresponding author. This achievement, accomplished entirely by domestic researchers, is recognized as a milestone that significantly elevates Korea’s standing in global plasma science and technology research.

For plasma physicists, plasma—often called the “fourth state of matter,” distinct from solids, liquids, and gases—presents the formidable challenge of explaining how microscopic instabilities can drive macroscopic structural changes. The problem of multiscale coupling has therefore remained one of the most fundamental and long-standing issues in the field.

Plasma, however, is not only the essential medium for nuclear fusion reactions but also the predominant state of matter in the universe. Accordingly, understanding multiscale coupling in plasma has long been considered critical for both advancing fusion energy technology and unraveling the origins of the universe.

The team of Dr. Park and Dr. Yoon analyzed experimental data obtained from SNU’s fusion device and verified their findings through particle simulations using the KAIROS supercomputer at the Korea Institute of Fusion Energy. Their results proved that when microscopic magnetic turbulence is triggered, magnetic reconnection occurs effectively, inducing macroscopic structural changes within plasma.

The joint research team demonstrated for the first time that microscopic magnetic turbulence, deliberately induced by a strong electron beam, can increase plasma resistivity, thereby driving magnetic reconnection and ultimately producing large-scale structural changes—a direct experimental realization and proof of multiscale dynamics in plasma.

The study is particularly significant as an interdisciplinary achievement, combining experimental operations of Seoul National University’s fusion device with theoretical simulations conducted at APCTP.

This achievement also reflects the sustained efforts of Seoul National University and APCTP to provide early-career researchers with opportunities at an international level and to foster interdisciplinary collaboration. It stands as a representative case of advancing the global competitiveness of domestic researchers and nurturing future leaders in science and technology.

Dr. Jong Yoon Park, BK Assistant Professor at SNU, noted, “This outcome was only possible through countless discussions and debates between experts in fusion and theoretical physics, who started from different interests but ultimately arrived at common ground.

It is particularly meaningful in that it offers new clues to understanding the onset of magnetic reconnection, a process that plays a key role in cosmic phenomena such as solar flares and geomagnetic storms.”

Dr. Young Dae Yoon of APCTP added, “We hope this research will not only expand the framework of interpretation in plasma physics but also serve as a foundation for the development of new fusion technologies.”