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    Kairyu, the giant underwater turbine that Japan hopes will become the "future of energy".

    June 17, 2022 - CE Noticias Financieras



      Japan is looking for an "inexhaustible" source of energy in the most unlikely place: the depths of the oceans


      The Asian country announced the successful completion of the three-and-a-half-year test phase of Kairyu, a superturbine with which it hopes to transform electricity production in its territory... and in the world.

      The project is a pioneer in the useof ocean currents

      to generate energy and its designers assure that it is one of the most powerful and least used natural sources currently in use, so they foresee that it could become part of the "future of energy".

      Although the sun - used for the solar panels - sets and the winds - used for the wind turbines - vary, the ocean currents follow a constant flow almost permanently, which is why the companies behind the project call it a truly "inexhaustible" source.

      The big challenge for decades for the Japanese was how to design a generator capable of withstanding the strong currents that pass close to their shores.

      Since 2017, the IHI Corporation teamed up with the technological New Energy and Industrial Technology Development Organization

      (NEDO) to test designs.

      They finally succeeded in getting one model to run for more than three years - Kairyu


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      The generator was able to produce 100 kilowatts of power steadily

      during that period, so now the companies will launch an even larger project.

      This is an expansion of Kairyu into a gigantic 330-ton structure that will seek to generate 2 megawatts of power.

      They predict it will be operational, if finally feasible, by 2030.

      What Kairyu

      Kairyu, whose name means "sea current" in Japanese,

      is like

      , features

      a structure about 20 meters long flanked by a pair of similarly sized cylinders


      Each of the cylinders features a power generation system connected to an 11-meter-long turbine.

      The device will be connected to the seabed by a kind of anchor and a power cable

      , which will also serve to transport the generated energy to the mainland.

      As IHI Corporation explains on its website, the design means that the device can move up and down to find the most efficient orientation of the current for power generation.


      Kairyu was designed to float some 50 meters below sea level and its mechanism, say the manufacturers, is based on the fact that, as it moves towards the surface, the resistance created provides the necessary movement to move the turbines


      The blades rotate in the opposite direction, which, together with a series of position sensors, means that the device remains relatively stable despite the dramatic movements of the water in that area.

      The superturbine will be placed in the so-called Kuroshio current

      , an ocean current that flows from the east of the Japanese coast in a northeasterly direction at a speed of 1 to 1.5 meters per second.

      The company behind the project estimates that, if the energy present in the current could be harnessed in further developments of Kairyu, it would be possible to generate around 200 gigawatts of electricity, an amount that represents 60% of what the country currently consumes


      A problem for Japan

      Japan is highly dependent on imported fossil fuels for power generation


      According to official data, the country imports more than 99% of its crude oil and about 98% of its natural gas

      , most of which comes from the Middle East.

      Although it has numerous nuclear power plants, this form of generation has become widely unpopular in the country after the Fukushima accident in 2011, one of the worst in history.

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      If before that year nuclear power accounted for one-third of all power produced in Japan, today, it is less than 4%.

      Fossil fuels are now the source from which a third of Japan' s energy

      is obtained, although in recent years the country has also begun to experiment with natural sources, which now account for 18% of generation, according to official data.

      However, the country faces a "natural enemy" for a greater commitment to renewable sources: its own geography.

      As a mountainous archipelago, Japan does not have large areas that can be used for wind turbine fields or solar panels and, being distant from other nations, it is more complicated to buy energy from other territories.

      The 2011 tsunami caused failures at the Fukushima nuclear plant. Getty Images The 2011 tsunami caused failures at the Fukushima nuclear plant.

      However, one thing it has to count on because of its geography is extensive coastal areas and strong ocean currents in its vicinity, hence the utilization of these has been in projects by various companies for decades.

      The challenges

      Although this is the first major project to seek to generate electricity from ocean currents, it is not the first to try to use the sea's movements for electricity generation


      Last year, the United Kingdom put into operation the so-called Orbital O2

      , a turbine that generates energy from the tides and has been able to produce 2 megawatts of electricity.

      Although Japanese media have been optimistic about Kairyu, they also recognize that the challenges ahead are enormous.

      Despite global interest in this relatively underutilized renewable energy reserve, previous attempts to extract electricity from tides, waves and open ocean currents have ended in failure.

      Among the main obstacles it faces are the high costs

      of building such a structure and placing it in the open ocean, the environmental problems it can generate, and the dangers of the proximity between coastal areas and the power grid.

      The very physical characteristics of ocean currents are a problem for the idea: they tend to be stronger near the surface, which is also the area where the power of the typhoons that generally affect Japan each year is felt most intensely and could affect the turbine.

      Although the more than three-year test succeeded in maintaining a stable power flow, its generating capacity is still very small

      compared to other renewable energy sources that have experienced greater technological development in recent years.

      Getty Images

      Experts on the subject interviewed by Bloomberg indicated that Japan does not


      the experience in offshore construction either

      , which also leaves doubts about the feasibility of the project, which requires work on the seabed.

      Being far from the coast and in conditions that are often hostile due to currents, there are also fears that its installation, operation and maintenance could lead to high costs that could, in turn, be reflected in the prices of the energy sold to users.

      Manufacturers, however, are hopeful that it will be a first step into the future as they seek to open the doors to an underexplored energy source.

      "NEDO hopes that the generation of electricity by ocean currents will become a new source of renewable energy," the company says.

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