A Japanese company plans to drop a huge machine into the ocean to generate power that is theoretically unlimited.
It comes at the right time as a number of countries around the world are dealing with rising energy prices and Japan is heavily dependent on importing oil and natural gas from elsewhere. In fact, the country’s reliance on fossil fuels rose from 81 percent to 89 percent between 2010 and 2016, according to Japanese government data.
During the same period, the nuclear power grid took a hit in the wake of the Fukushima disaster, shrinking from 11.2 percent to less than one percent.
Some renewable options, such as large wind farms, are not ideal, in part because of Japan’s generally mountainous terrain.
As a result, tidal energy remains one of the few remaining standout choices if Japan is to build a sustainable and domestic energy supply.
To harness this tidal force, Japanese engineers at Ishikawajima-Harima Heavy Industries (IHI Corporation) built a 330-ton tidal power plant called Kairyu. It consists of a 66-foot central cylinder with two more cylinders on either side to which both 36-foot turbine blades are attached.
When operational, Kairyu will be attached to the ocean floor with cables to hold it in place. It will then use the power of the water flows around it to spin the turbines that will generate power. This can then be transferred to Japan’s national power grid.
The company has been working on the machine for years and completed a three and a half year test off Japan’s southwest coast in February this year, Popular mechanics reports.
IHI estimates that one day it could be possible to generate about 205 gigawatts of electricity from the tides around Japan, which would be about enough to meet all of the country’s energy needs. But there is still a long way to go.
Kairyu, while huge, is capable of generating 100 kW of power. This is not much compared to the average onshore wind turbine with a capacity of 2.5 to 3 MW or more than 6 million kWh per year – enough to supply 1,500 average European households with electricity, according to the European Wind Energy Association.
Then there are the broader challenges of tidal energy. For starters, it’s expensive due to the high initial cost of installation and maintenance, according to the Massachusetts Institute of Technology’s climate portal. There is also a lack of an established manufacturing market.
Still, some countries, such as Scotland, have introduced tidal systems. For IHI, the hope will be that tidal energy can be an energy source with enormous potential if it can be tapped effectively.