Innovative Japanese Turbines Set to Harness Ocean Energy
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Chapter 1: Harnessing Energy from Ocean Currents
Japan is embarking on an ambitious project to utilize ocean currents for energy production. Recently, a three-and-a-half-year trial of a prototype device designed to generate power from these currents has concluded. The goal is to develop a full-scale version capable of producing electricity by leveraging the movement of water.
Over 70% of the Earth's surface is covered by water, with more than 96% of this water found in oceans. These vast bodies of water are in constant motion, influenced by the Moon’s gravitational pull, which creates tides, and by ocean currents generated through the Earth’s rotation, wind patterns, and temperature variations. This dynamic movement suggests that ocean waters could serve as significant sources of renewable energy. If we can harness energy from winds, it stands to reason that we can do the same with water. However, the technology to exploit sea currents, tides, and waves is still developing and primarily exists on a small scale.
Section 1.1: The Kairyu Prototype
Japan has conducted a test of an innovative device developed by IHI Corporation, which has spent over a decade refining underwater energy generation technology. The result is the Kairyu, a 330-ton prototype named after the Japanese term for “ocean current.”
The Kairyu features a substantial 20-meter hull, with two attached cylinders housing power generators equipped with 11-meter turbines. Positioned 50 meters underwater and anchored to the ocean floor, the Kairyu can adjust its orientation to maximize energy capture from water flow.
Section 1.2: The Potential of Ocean Currents
Japan has a historical commitment to low-carbon energy. However, the Fukushima nuclear disaster in 2011 caused public support for nuclear energy to plummet, leading to a reliance on energy imports for 90% of its needs. Consequently, Japan is actively seeking alternative energy sources. Among the options being explored is the powerful Kuroshio Current along Japan's eastern and southern shores, which could hypothetically generate 205 gigawatts of electricity if fully harnessed—equivalent to the country's current energy output.
Section 1.3: Current Energy Generation Capabilities
At present, the Kairyu prototype is not capable of harnessing a significant portion of the ocean current energy. Operating at speeds of two to four knots (one to two meters per second), it currently produces just 100 kilowatts, considerably less than the average wind turbine, which generates over 3 megawatts. Nonetheless, IHI Corporation suggests that scaling up the device could yield around 2 megawatts by employing 20-meter-long turbines.
Chapter 2: Future of Ocean Energy in Japan
If the Kairyu can be expanded effectively, Japan could see its first underwater power plant operational within the next decade. Should the technology prove both efficient and environmentally sustainable, ocean energy could eventually meet 40–70% of Japan’s energy requirements. However, current global ocean energy installations only provide between 10 kW and 1 MW, which is insufficient to achieve the zero CO2 emissions goal set for 2050, requiring an annual increase of 1 GW of ocean energy by 2030.
Sources: IHI Corporation, world-nuclear.org
The second video titled "Clean energy: New Japanese turbines generate electricity from sea waves - TomoNews" explores the advancements in turbine technology.
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