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This Revolutionary Technology Could
Unlock The World’s Cleanest Energy
By Will Lockett
April 23, 2023
The world is waning under the immense weight of
our vast carbon emissions and rife ecological crimes. If we carry on
in this way, then Earth will no longer be our bountiful garden of Eden
and instead resemble something far closer to hell. To stop this Hadian
vision of the future from coming true, humanity needs to rapidly
change its ways and decarbonise. We’ve made great strides in recent
years, but we have neglected one of the cleanest forms of energy. You
see, the lifecycle carbon emission of coal energy is 820 g/kWh, while
solar is much lower at 48 g/kWh, and wind and nuclear are even lower
at just 12 g/kWh. But tidal power trounces them all at only 1.8 g/kWh!
Yet, despite these astonishing eco-credentials, we hardly use tidal
power. Thankfully, Orbital Marine is set to change that with its
revolutionary O2 tidal turbine.
Before we look at Orbital Marine’s O2 turbine, let’s first recap what
tidal energy is, why it is so clean, and why we don’t use it.
The ocean tides rise and fall twice a day. In some places, this causes
ocean water to flow gently, but in other places, it causes a torrent.
All tidal power does is place a turbine underwater where the tidal
flow is particularly strong and produce electricity in the same way a
wind turbine does.
But if that is the case, then how can tidal power have a substantially
lower carbon footprint than wind power? Well, it has all to do with
the weight and viscosity of water.
The blades of a turbine are far more efficient in water than in air.
This is because water’s viscosity and weight allow higher pressure
differentials to be built over their surface without generating too
much energy-wasting turbulence, creating more force over the blades.
As such, a tidal power turbine is a whopping 80% efficient, whereas a
wind turbine is at most 40% efficient. This allows tidal power to pull
far more energy from the tides than wind turbines can from the wind.
However, water weighs nearly a thousand times more than air. The
equation for kinetic energy is K.E. = 1/2 m v², which means water can
carry a thousand times the kinetic energy of air for the same flow
rate! This means a typical two-mph tide will contain the same kinetic
energy as 2,000-mph winds for the same flow measured in volume per
minute.
These factors combined mean that a single tidal turbine can produce
far more power than a single wind turbine. Therefore, less
carbon-intensive mining, manufacturing, or construction needs to take
place, giving tidal power its brilliantly low carbon emissions. This
is further aided by the fact that the energy produced by tidal waves
is consistent and predictable. In other words, it requires far smaller
grid batteries to meet demand than wind or solar, which can lag behind
energy demand for days at a time. These batteries are carbon-intensive
and environmentally dubious to produce, so using fewer of them has a
massive overall impact on tidal’s carbon footprint.
So what’s the problem with tidal power, then? Well, it is damn
expensive! The ocean is a horrific place to build moving structures,
as the water corrodes them and the pervasive life can damage even the
most sturdy designs. What’s more, tidal turbines are produced in such
small numbers that they cost a stupid amount to build, as there is no
economy of scale. This is why tidal power costs, on average, around
$311 per MWh. For some context here, nuclear power is by far the most
expensive and widely used energy source, and it peaks at $211 per MWh.
Meanwhile, wind power costs at most $50 per MWh. As such, we simply
can’t afford to use tidal energy.
But this is where Scotland-based Orbital Marine Power comes in. They
are aiming to change this with their O2 tidal turbine, which happens
to be the world’s most powerful tidal turbine.
The O2 turbine is a piece of genius engineering. Rather than
mounting the turbines on a pylon, like most tidal turbines, these are
attached to a 72-metre-long floating platform that is anchored to the
sea floor. The two turbines are mounted on massive swinging arms on
either side of the platform, meaning they can be easily hauled out of
the water for simple maintenance, and all the vital electronics are
incredibly easy to access, which drives down operational costs. The
turbine blades are massive, with a 20-metre wingspan, allowing them to
capture as much energy as possible, giving the O2 a power output of
2MW or more. This higher output means fewer turbines are needed to
meet power demand, meaning they can be more efficiently produced,
resulting in an overall cheaper tidal power solution. Because the O2
is basically just a medium-sized ship, its construction and
installation are far easier and cheaper than any other form of tidal
power, as it doesn’t require any specialist vessels and production
facilities already exist. Because the O2 doesn’t rely on building
directly upon the sea floor, it can also be installed in a far greater
range of locations than a pylon-based turbine; this makes it far more
flexible and, therefore, cheaper.
Orbital Marine has already
deployed one O2 at the European Marine Energy Centre, and it has been
supplying energy to the UK grid since July 2021. Sadly, I could
not find what price per MWh this O2 is selling its energy for, but it
must be good because Orbital Ocean has just won a massive contract!
This Option Agreement is to build a 30 MW tidal power plant in the
Westray Firth, where the tide rips by at 3 m/s. This would make Orbital
Marine’s first full-scale tidal power planet the fifth largest in the
world. However, three of the largest tidal power sites are lagoon
sites, which are far less eco-friendly than free-floating turbines
like the O2. Orbital has confirmed that the necessary power connection
is already there, and it will only take 12 O2 units to meet this power
demand.
This is where the price of tidal power starts to get better. You see, Orbital
Marine says that tidal power — in particular, free-floating tidal
power like the O2 — is on target to reach $110 per MWh, which
would make it a highly competitive energy source. To achieve this
price point, tidal power needs to reach a global capacity of 1 GW
(1,000 MW, or 33 of Orbital’s new power plants). Once at this size,
economies of scale can set in, along with establishing a tidal power
industry — where trained technicians and tools become available,
alongside the development of third party support systems — which will
send the price way down to $110 per MWh.
Orbital Marine’s revolutionary turbine has a fantastic shot at
reaching this 1 GW mark quicker than anyone else, thanks to its design
being easy to build and install, so it really could unlock this
planet-saving technology. Only time will tell, but I can’t wait to see
where Orbital Marine goes from here.
Green Play Ammonia™, Yielder® NFuel Energy.
Spokane, Washington. 99212
www.exactrix.com
509 995 1879 cell, Pacific.
exactrix@exactrix.com
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