Minesto: Revolutionising Ocean Energy

Shadine Taufik

At an astounding 80%, most of the world’s energy comes from fossil fuels, primarily natural gas. This is concerning, as these materials are not only non-renewable and quickly depleting, but they also release vast amounts of carbon dioxide when combusted, contributing to climate change. Due to this, governments have been looking to adopt clean, renewable energy.

Biomass, geothermal, nuclear, wind, and solar energy are some examples of power sources currently in use that harness natural phenomena for energy. Another popular example is hydropower, which is generated by water in motion through manmade ‘waterfall’ dams. In a relatively recent breakthrough, a Swedish company has successfully reimagined hydroelectricity.

Marine energy technology developer Minesto has created Deep Green – technology that uses underwater ‘kites’ to generate electricity.

The company, founded in 2007 as a spin-off from Saab, a Swedish aerospace manufacturer.

Deep Green has been testing since 2013, though most recently, the technology has afforded its electrical services to the Faroe Islands in the North Atlantic since 2020.

The power is generated by two kites, which are wired and supply the local electricity company SEV, as well as the island’s national grid.

Currently, they are also testing their Deep Green technology in Northern Ireland and Wales, and have undertaken projects in Taiwan and the United States.

How does it work?

Recalling a mundane scene, Minesto’s website reads:

‘Imagine that you are standing on a beach, flying a kite in the wind. You feel the strong lift force from the kite in the rope as the wind tries to carry the kite away. As you move the kite sideways, you notice that it flies fast – way faster than the wind is blowing.’

The mechanics of this concept are the basis of their invention – their model consists of a turbine attached to a kite-like machine that utilises water currents to ‘fly’ in place of the wind.

Minesto’s entirely novel model flying component bears a closer resemblance to an aeroplane than a kite. A five-metre wing pushes the turbine through the water in a figure-eight motion, which ‘[sweeps] a large area at a relative speed that is several times the actual speed of the underwater current’. This wing movement is autonomous, moving through low-tidal streams and ocean currents, thrust forwards by this hydrodynamic lift force.

Additionally, the electricity produced by the circling kite amounts to electricity output that is several hundred times greater relative to a stationary one, as the speed of the wing affects power production.

In the energy transfer, the turbine diffuses power to the connected generator, which then outputs the electricity through a power cable in the tether. Subsequently, the electricity is conducted onshore.

With the present iteration of Deep Green, one kite can power around 50 to 70 homes.

In an interview with the BBC, Minesto’s chief executive, Martin Edlund, confirmed that the company has bigger plans for the future:

‘The new kites will have a 12-metre wingspan, and can each generate 1.2 megawatts of power [a megawatt is 1,000 kilowatts]. We believe an array of these Dragon-class kites will produce enough electricity to power half of the households in the Faroes.’

How is Deep Green different?

Deep Green’s technology is fairly distinctive from both hydroelectricity and wind energy. Hydroelectric dams convert the kinetic energy of falling water into mechanical energy. On the other hand, wind turbines use their blades to collect kinetic energy, transforming it into electricity. Additionally, as wind turbines are stationary, they do not optimise and create as much energy from the wind as the Minesto ‘kites’ do from the currents.

Additionally, energy production is 100% predictable, as the tides that generate the electricity are measured by the relative motion of the sun, earth, and moon.

Edlund explained:

‘In an island location there is no possibility of bringing in power connections from another country when supplies run low. The tidal motion is almost perpetual, and we see it as a crucial addition to the net zero goals of the next decade.’

40% of the energy used on the Faroe Islands is hydroelectric, with wind power contributing 12%, and fossil fuels and diesel imported from the mainland making up the rest – which is almost half. Deep Green is extremely useful in providing renewable backup energy when weather conditions are not favourable.

As the ‘kites’ are underwater, they remain hidden, have very little environmental impact, and also require a minimal number of tools to install.

The state of renewable energy

Renewable energy has been adopted at a greater level within the past few years, and the UK is hoping to decarbonise power generation by 2035, making the energy that is used and produced 100% renewable, and cutting carbon emissions by 78%.

Currently, most of the renewable energy used in the UK comes from onshore and offshore wind power plants, with solar energy being the second greatest source. As discussed earlier by Edlund, power generation that is dependent on weather, such as the wind and the sun, is a lot less reliable than the characteristically calculated nature of tides. This is especially relevant due to the adverse effects of climate change. Adopting more water-based energy sources such as Minesto’s Deep Green could provide countries with more dependable clean energy.

Investing in technology such as this is essential in slowing down the toll that fossil fuels have had on the environment, paving the way for a more sustainable future. The worrying state of global warming has pushed countries, syndicated through the United Nations, to set their own net-zero goals to prevent further planetary destruction. This means that Deep Green and similar innovative power generation techniques will be key players within the next five to ten years.

About the Author: Shadine Taufik

Shadine Taufik is a contributing Features writer with expertise in digital sociology and culture, philosophy of technology, and computational creativity.