Japan is seeking to develop alternative energies such as offshore wind and hydrogen, which can adapt to the country's geography, but also to the climate events it experiences.
Producing alternative energy is a priority for Japan. The country aims to reach between 36%-38% of renewable power supplies and reduce its greenhouse emissions by 46% by 2030, and energy policies will be one of the issues at the top of the agenda at the G7 Summit to be held in Japan in mid-May.
Its technology is at the forefront of this green revolution, and in this latest episode of Spotlight, we travel to the remote Goto Islands in the Prefecture of Nagasaki, in the South of Japan, to visit a milestone offshore floating wind farm.
Goto's floating wind farm
With limited land but a large coastal area, offshore wind power could be the answer to Japan’s future energy needs, but it comes with challenges.
Goto is one of the most hard-hit typhoon areas in Japan, a strategic testing zone for the resistance of these floating turbines.
Japan relies on both floating and bottom-fix turbines to generate power. The bottom-fix wind power station of Akita was the first large-scale offshore wind farm in the country. Both types are adapted to Japan's complex topography and natural disasters.
"The fixed type has to be fastened to the seabed, but in Japan the sea gets deep very quickly," explained Ushigami Kei, the Executive manager of Goto Floating Wind Farm LLC.
"It is built by setting first a foundation on the seabed, so it is affected by the topography and geology of the seabed. The floating type is connected by a chain, but it is strong against earthquakes because it is not affected by the sea ground topology."
The challenge for these floating structures is to deal with typhoons and the power of waves. Stabilisation mechanisms take knowledge from shipbuilding technology to minimize the swaying.
“The structure is designed to be stable by lowering the centre of gravity with heavy concrete elements on the lower part of the floater. This makes the structure resistant to the strong winds of typhoons," Ushigami Kei added.
Ground surveys play a key role in designing cutting-edge facilities like Goto’s to withstand natural disasters.
Professor Ishihara from the University of Tokyo is one of the most renowned engineers working on risk evaluation of wind.
"In the case of Japan, not only are very strong typhoons blowing, but the usual winds are not very strong. Therefore, we need to solve those two problems at the same time," he explained.
"One solution is to lengthen and slim down the blade. By increasing the length, the normal power generation also increases. Thinner blades also reduce excess wind during typhoons. By using Japanese carbon fibre technology, it is possible to create very long, thin and strong blades."
Goto Wind Farm will start commercial operations in January 2024.
Hydrogen cargo vessels
The port of Kobe is home to the world’s first liquified hydrogen carrier. Hydrogen is another clean energy that Japan is focusing on. It was the first country to draw up a hydrogen strategy in 2017.
Now it is planning an ambitious new target to boost annual supply to 12 million tonnes for 2040. Hydrogen is produced in Australia and shipped to Japan by sea, freezing it to minus 253 degrees Celsius and compressing it into a liquid.
It has done the round trip twice since it was launched in 2021.
“Here we have the hydrogen tank, here in blue you have the mouth and under there is the tank. The size of the tank is 1,250 cubic meters," revealed Yamamoto Shigeru, the Executive Officer and Deputy General Manager of the Hydrogen Strategy Division for Kawasaki Heavy Industries, Ltd.
Kawasaki Heavy Industries has developed a full hydrogen supply chain in Kobe, providing heat and power supply to the urban area.
Japan relies largely on the import of hydrogen. To use it as a regular energy source, it is necessary to reduce the costs.
"The cost of hydrogen can be reduced by transporting it in larger quantities. In order to bring the cost down to the same or even less than fossil fuels it is necessary to scale up first," Yamamoto Shigeru explained. "To reach that purpose, we will build large ships and also large tanks at the receiving base. We would like to create a larger infrastructure and scale it up for commercialisation."
The next project is a large-scale vessel more than 100 times bigger.
With this focus on innovation, Japan is pioneering the global clean energy transition and moving closer to achieving its climate change ambitions.