Japan, a leader in technological innovations, has successfully tested a system that uses the power of the ocean currents to generate renewable energy. The system has been in the making for over ten years and it represents and important step in the search for renewable energy sources that can decrease the dependency on fossil fuel, which is very high in Japan.
The device has been in trials in the Pacific Ocean, home of the Kuroshio current, also known as the Black or Japan current. This is a warm ocean current and it is known as one of the strongest in the world.
The aim of IHI Corp, the developer of the system, was to build a machine that can use the energy of the ocean current to create a stable source of electric power. As a resource, the main advantage of ocean currents is that they are extremely stable and predictable, in comparison to the wind and the sun. According to Bloomberg, in the case of ocean current, the “capacity factor — a measure of how often the system is generating — [is] of 50-70%, compared with around 29% for onshore wind and 15% for solar”.
The system built by IHI Corp is a giant turbine that is similar to an airplane. The prototype is called Kairyu and it weighs around 330 tons. The device has been in testing for approximately three and a half years, during which it proved that it can generate 100 kilowatts of power. The company intends to increase the energy production to 2 megawatts and it plans to implement the system for commercial operation until the late 2030s.
Apart from ocean currents, Japan is also researching other sources of renewable energy, such as tidal and wave power, or ocean thermal energy conversion (OTEC). The most significant advances have been made in the technology of tidal stream, which also involves the lowest costs. The difference between ocean currents and tidal flows, is that the latter are usually stronger and can generate power in a more cost-efficient way. According to marine energy analyst Angus McCrone, “the biggest issue for ocean current turbines is whether they could produce a device that would generate power economically out of currents that are not particularly strong”.
While the system developed by the Japanese company has potential, there is still a long way to go until it can be efficiently implemented. However, considering that Japan does not benefit from many other sources of renewable energy, ocean currents are worth considering in the race to reduce fossil fuel dependency. The biggest challenge is to create a technology that can provide good results and that can be used with reduced costs.