Renewable energy from deep sea currents

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Written By Tony Lopes

Sustainable marketer and clean energy specialist. 

Japan’s IHI Corporation has successfully tested a way to generate renewable energy from deep sea currents. Deep ocean turbines harness infinite green power as a form of hydro energy.

The 3 and a half year study was completed in February 2022 near the Tokara Islands.

Japan is a highly industrialized nation with significant energy requirements. Most of this energy comes from fossil fuels (which pollute the air and create climate change) but scientists are working on solutions.

One of the alternative energy options which has been successfully tested is a deep sea turbine which uses energy from ocean currents to create constant, clean energy.

The sea is an infinite supply of energy and this is mostly seen with tide and wave energy generation, but the subsea turbine is an innovation with excellent test results.

The 330-ton turbine, named “Kairyu”, looks like a massive jet engine and the entire rig consists of two counter-rotating turbine fans and a central buoyancy control platform.

The platform is anchored to the sea bed at a depth of between 30 and 50 meters (100 to 160 feet) in the Kuroshio Current which is a very strong sea current off the eastern coast of Japan.

Electricity generated by the sea turbine will then be transmitted to land via underwater cables along the sea bed.

Japan does not have access to much wind power, unlike other parts of the world. This innovation could generate as much as 200 GIGAWATTS of clean energy which is about 60% of what Japan currently needs.

Japan has deeply invested in wind and solar energy too, especially offshore wind turbines. Sea energy from deep underwater currents will add significantly to the country’s clean energy production.

What’s really great about energy from sea currents is the reliability. The current is steady and the flow is at relatively constant speed. This makes it easy to predict and manage energy production from sea turbines.

This is not the first time a sea turbine has been tested and deployed

The Orbital 02 turbine generates 100 GIGAWATTS of clean energy. This is enough to power 80 million homes.

The Orbital 02 is 72 metres long (236 feet) and has massive underwater rotors which capture the flow of energy from sea currents.

This model can also be used in rivers to capture energy from river flow. Imagine the possibilities available in all the rivers of the world!

A single turbine like the Orbintal can offset 2,200 tons of CO2 annually, which will help with the global fight against C02 emissions and climate change.

What is Orbital’s mission?

Orbital is working on ways to make Earth a healthy and cleaner place for our children and future generations.

The name “Orbital” takes inspiration from the energy created by the orbital movement of the moon and planets on our oceans. Tidal movements are accelerated in certain parts of the ocean to become giant undersea rivers and currents.

Tidal streams offer massive energy potential and best of all, they are predictable.

The team at Orbital has spent the last two decades developing the turbine technology that will be used to harness this tidal energy.

The concept is unique because turbines are attached to a floating platform instead of being anchored to a fixed place on the sea bed. This makes it easy to move the turbines to areas where they can generate the most energy.

This also means the floating platform sea turbines can be built and services more cheaply than fixed-position turbines.

The 02 has a main tube structure which acts as a floating hull. This hull is fixed in place with an anchoring system and contains all the power management and electrical conducting equipment needed to manage and transmit energy to undersea power cables.

The floating hull has two long arm structures with rotors that capture the energy from the sea current. These arms are hinged so they can be raised to the surface for any maintenance that needs to be done.

The latest model is the same length as a Boeing 747 jumbo jet.

Orbital O2

The rotors are strong enough to pick up more than 20 double decker busses.

How efficient are tidal turbines?

According to this visual from Bloomberg, tidal turbines have a similar energy capacity as coal powered plants and are significantly more efficient than solar and wind energy sources.

Japan Clean energy Bloomberg

This means the future of tidal energy is boundless and currently untapped. The sea itself may hold the key to the clean energy solutions of the future.

If the current efforts to harness sea tidal power are successful, deep ocean currents could become an integral part of the Earth’s energy production. This will require collaboration between corporations and governments to prove the financial viability of these projects and to develop them at scale around the world.

Of course this form of energy is location dependent and will benefit countries close to sea currents or strong, deep rivers. The supporting infrastructure must also be developed to transmit energy to the grid in a secure, reliable way.

Most importantly, government support is needed and this requires public pressure to move away from fossil fuels which currently support most governments through direct lobbying and corruption.

Ocean energy will also need to compete with other renewable forms of energy. The cost of solar and wind is declining and battery storage is becoming cheaper as technology develops and competitors in the market increase.

The price of sea energy will need to be compared to solar, wind and other forms of energy and the market will determine which will grow based on price and reliability.

We know that tidal power by itself cannot solve all the energy challenges we face but rather form part of the combination of renewable energy solutions to oppose fossil fuels and the climate emergency.

It is estimated that globally there is about 100 GIGAWATTS of tidal energy available for harvesting which could look after the energy needs of 80 million homes. This doesn’t include all the other ways we can harvest energy from the oceans.

What next for tidal power?

What are your thoughts on the future of tidal power and energy from the oceans?

If you work in the industry or have some thoughts on this, let us know in the comments below and let’s start a conversation about this exciting source of clean energy.

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