Japan to sink giant turbine into ocean capable of generating virtually limitless energy
There is a source of energy hidden in the depths of the ocean waves that is unlike any other. To achieve this, Japanese engineers built a real Leviathan – a monster that can withstand the strongest ocean currents and convert its flow into virtually unlimited amounts of energy.
IHI Corporation has been working on this technology for over ten years, and in 2017 began design collaboration with the Japan New Energy and Industrial Technology Development Organization (NEDO) for design testing.
In February 2022, the project overcame a key milestone – successfully completing 3.5 years of field tests off the southwest coast of Japan.
The 330-ton prototype was called the Kairyu, which in Japanese roughly means “ocean current.” Its structure consists of a 20-meter-long fuselage (hull), which is surrounded here and there by two cylinders of the same size, and in each of them is placed an energy generation system, which is attached to the wing of an 11-meter-long turbine.
The device is connected to the ocean floor with rods and power cables and can orient itself to select the most efficient position and generate energy from the impact of deep water currents, and then transfer it to the system.
Japan is heavily dependent on imports of fossil fuels, from which it generates a significant portion of its electricity. Because of the mixed public sentiment towards nuclear energy following the 2011 Fukushima nuclear disaster, Japan is motivated to focus its technological advances on renewable energy sources.
Unfortunately, the mountainous terrain of the Japanese archipelago does not allow for large-scale placement of wind turbines or solar panels. Neither have neighboring countries to engage in electricity trade with them.
One of the things the country can use is its vast coastal waters. To the east flows a large current – the North Pacific Circulation.
Off the coast of Japan, the rotation is transformed into a relatively strong stream called the Kuroshio stream.
The IHI estimates that if this current is to be generated, it should be possible to generate about 205 gigawatts of electricity, which is about as much as Japan currently generates.
This enormous potential in the turbulent movements of the ocean also makes it difficult to use it as a source of energy. The fastest moving water is near the surface where typhoons often occur and power plants can easily be destroyed.
Kairyu was created to sink to a depth of about 50 meters in the water – traction on the surface generates the thrust needed for the turbines. Each wing moves in opposite directions from each other, which keeps the device relatively stable.
Moving at a speed of 1-2 meters per second, Kairyu generated 100 kilowatts of energy.
This may seem too small for the capacity of a wind turbine located near the coast, which will generate 3.6 megawatts, but in this case the main thing is that Kairyu has proven durability; Consequently, he may soon have a monster twin, a 20-meter-long turbine capable of producing 2 megawatts.
If all goes according to plan, we may see a whole farm of such generators in the near future.
Despite the huge interest in unused reserves of renewable energy, attempts to get energy from tidal, waves and open ocean currents have largely failed. Expensiveness, environmental constraints, distance from the coast – these are all great challenges for these types of projects.
If IHI Corp. overcomes these problems, it is possible that the ocean will meet 40-70 percent of Japan’s electricity needs in the coming years.