Sea currents, an endless energy source

It is not a secret anymore, our environment is now in danger. Still recently, a WWF report previewed the massive extinction of almost half of all the animal species and 69% of all the vegetal species within only 60 years. It is important to act and to act right now. The ecological transition is the only solution, it is essential to start with the energy transition. We have to rethink our energy system, both at the local and the global levels. We need to promote research, to implement and to use tools that allow the supplying of a clean and sustainable energy.

And for that, water is one of the first natural goods to use. The currents move at all times, as sea tides or waves. Even if their speed doesn’t go over 20km/h, they offer an important driving force because the water flows and density they present are tremendous. The energy produced by sea currents let us hope that we will be able to produce a huge quantity of energy using this sustainable and endless energy source that are the oceans, even if as of today its development is still expensive.

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INNOVATIVE COMPANIES WORLDWIDE

Australian company Carnegie is specialised in ocean waves technology. After years of research and around 140 million dollars of investment their technology is finally entering its commercialization process.

Thanks to huge investments, from the company first and the public sector then, Carnegie was able to create a few generators. The last of which, CETO 5, is made of larges buoys with a diameter of 11 meters which are immersed in the open sea. The wobbling created by the waves’ movement creates hydraulic pressure which is then converted in electricity in a power plant located on the shore.

Carnegie explains here how CETO 5 works.

Last year, three of Carnegie’s buoys set a new record by producing 1 megawatt of electricity for 14.000 hours of work, that being the electric bill for almost 2000 australian households. Moreover this method also allowed them to produce desalinated water for domestic use.

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AN ENERGY SOURCE KNOWN SINCE ANTIQUITY

Unlike solar or aeolian energy, the waves are a reliable and steady source of energy all year round. And the idea if using waves to produce energy has been around for a very long time now. Since antiquity, tidal mills have used the power of tides to activate their mechanisms.

In 1966, France opened the first tidal power plant. “L’usine marémotrice de la Rance”, in Britain was the biggest tidal power plant plant in the world with a capacity of 240 MW until 2010 when it was ousted by the Sihwa Lake tidal power plant in South Korea (with a capacity of 255 MW.)

This project cost around 620 million francs, being 152 million canadian dollars. The electricity produced can be used to power a city of 225 000 people (A city like Rennes). Although the dam has had ecological consequences such as the gradual silting of the Rance.

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HUGE ECONOMIC CHALLENGES

In 2010 quebec’s officials announced the launch of a pilot project with the goal to make Quebec a “major league player in emerging energies”, partly thanks to the development of hydrokinetic technology. Very much like wind turbines, tidal turbines are built around a turbine activated by marine currents energy.

The company RSW RER received several grants from Quebec and Canada’s governments. These grants represent a total amount of 5 million dollars and will help the company to set up their project (18 million dollars) : install two tidal turbines in the Saint-Lawrence River, near the Concord’s Bridge. This project has brought hope to a lot of people, especially because it would create green energy for northern villages. Currently, these villages receive electricity from oil-fired plants, which are an ecological disaster.

At first, the project was to build over three years 6 turbines in Montreal’s harbour, to form a partnership with aeronautic-industry giant Boeing and Hydro-Quebec and to set up a tidal turbines factory in Bécancour. However, after a test period and the building of two tidal turbines, only one will be immersed in the Saint-Laurent. By the end of 2013 the project is sinking, and the dream of becoming a world leader in tidal turbines building with it

Hydrokinetic technology still has nice days ahead of it. Last year, a tidal turbine was set up in the Bay of Fundy, near New-Scotland’s shore, and it has already began to transmit energy to the New-Scotland’s electric network. On the other side of the Atlantic Ocean, in France, almost forty tidal turbines will be set up in early 2019 in the Rhône River and it will be the largest hydrokinetic power park worldwide.

Today we can see a lot of innovative projects revolving around hydrokinetic energy being born. We need to change the way we live, starting we the energy we use. We need to be actors of the transition and to keep coming up with innovative solutions for our future.