For over a decade, Japan’s IHI Corporation has been working on Kairyu, a sea turbine that can harness the power of the ocean currents. Developed in collaboration with NEDO, the 100kW and 330-ton tidal power plant features a 66-foot central cylinder with two extra ones on each side, each carrying 36-foot turbine blades attached to them. In February 2022, the firm announced it had completed a 3.5 year-long trial and that the turbine should be expected to be up-and-running sometime in the 2030s.
In the field of energy regeneration, photovoltaic power generation and wind-power generation are becoming widespread. Meanwhile, Japan, having the world’s sixth-largest territorial waters and an exclusive economic zone, needs ocean renewable energy to be realized. A variety of approaches to the realization of ocean renewable energy have been proposed. Approaches include current in the open sea, such as the Kuroshio, to rotate turbine rotors; tidal flow power generation, which uses tidal flow in a strait or the like to rotate turbine rotors; wave-activated power generation, which uses the vertical motion of waves; ocean thermal energy conversion, which uses the temperature difference between surface and bottom; tidal (level difference) power generation; and seawater concentration difference power generation.
Japan is located near the Kuroshio, one of the world’s most powerful ocean currents, and one estimate states that if the energy present in the Kuroshio could be harnessed, it would amount to approximately 205 GW, which is comparable to Japan’s total electric power generation. Ocean current power generation is a harvesting method of ocean renewable energy. This energy regeneration technology is intended to effectively utilize the Kuroshio Current and is suited to Japan. The Kairyu system will be installed below sea level along Japan’s eastern coast. Once it is secured to the ocean floor via anchor lines and power cable, the turbine will find the most efficient position and start generating power through the water current.
Sounds great...., but not expected to be up-and-running until the 2030s..... ??
This sounds like a deep sea marine turbine which only runs in one direction unlike a tidal turbine which reverses flow as the tide turns. So it should be simpler than the ones that we have been developing only proofed against much greater external pressure from use at greater depths, possible.
When the Japanese get these running I wouldn't be at all surprised to see companies rushing to by them to install in British waters rather than buying underfunded British made ones. We have some of the best engineers in the world and most of the worst financiers and civil servants. So much British engineering development goes abroad for final commercial development because the companies can't get the finance in this country to get stuff to market. British financiers would far rather flog ponzi bits of worthless paper derivatives around the world than give money to British engineering.
I blame it on the education system which doesn't value technical education as much as The Classics and private schools don't help in this regard either, being designed to produce administrators for the Empire! The empire has gone, folks, welcome to the new world of engineering and manufacturing of which most graduates have no knowledge at all.
When I went to college there was a requirement for all scientists and engineers to do Liberal Studies which included at least one foreign language and a knowledge of the "arts". There was no requirement for arts and business students to study general science or basic engineering as that wasn't considered an important part of life.
I hear there are entire "Liberal Arts" universities in the states where you doing need to get out a calculator at all. As long as you can BS your way through the exams you are all go for a career in politics or the humanities.
Back to the tidal current question. Global currents play a role in transferring heat around the globe. As long as the currents are not stopped sufficiently to induce ice ages in countries where the heat is transferred to then all good. I could see future global wars being started over who stole my warm current. Putting my non liberal arts cap on for a moment I think if water is considered the same as air is in wind turbine calculations then the maximum amount of energy that can be extracted is the Betz limit, or 59% of total kinetic flow energy. otherwise you stop the current and also your turbines.
Working on the basis that the sun shining on a fraction of the Sahara desert can supply all the world's current energy demand then the proportion of that energy transferred to the ocean currents should also be able to meet a large part of the world energy demand without a major slow down.
As long as we don't continue with exponential growth in energy use the Japanese should be able to extract what they can without harming the environment too much. It is the growth which would cause problems.
We don't have any ocean current locations but we have plenty with very strong tidal flows. I'm sure that it is not beyond the wit of the Japanese to make a few modifications to enable bi directional generation given the level of investment that they will put in, unlike our government or the city.
Maybe they need to get it up-and-running before the 2030s..... ??
Grid tied PV would help with daytime peak demand. During the hours of peak air conditioning use it is ALLWAYS daylight and often sunny. Grid tied PV is proven technology and available right now.
Air conditioning is essential in the temperatures reported, but could be used more prudently. Cooling to 23 degrees rather than to 20 degrees would save energy.
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"
