The Floating Tidal Turbine Built for Series Production
How does a floating platform anchored in the ocean generate predictable clean energy from tidal currents without relying on wind or sunlight?
Photo source:
Orbital marine
The Story Behind the Orbital O2-X
Most renewable energy conversations focus on
solar panels and wind farms. Tidal energy, which generates electricity from the
predictable movement of ocean currents, receives far less attention despite one
significant advantage. Tides are predictable. Unlike wind and sunlight, they
follow a reliable schedule that does not depend on weather conditions. Orbital
Marine Power, a Scottish company founded in Orkney by Barry Johnston and led by
CEO Andrew Scott, has spent over two decades developing floating tidal turbine
technology to harness that resource.
The company's existing turbine, the O2,
established the core concept. It is a floating platform that sits on the ocean
surface while twin rotors hang beneath it on retractable legs, capturing energy
from tidal currents flowing underneath. The O2 introduced 360-degree blade
pitching, which allows the blades to adjust their angle as currents reverse
rather than physically rotating the entire structure. This enables the turbine
to capture energy from both ebb and flood tides without interruption. The O2 can
be towed to its installation site by a standard vessel and towed back to shore
for maintenance, eliminating the need for expensive heavy-lift ships. Since it
began operating, it has not required a single heavy-lift vessel intervention,
with all maintenance carried out using small workboats. The system is anchored
to the seabed using a mooring system and connected to the onshore electricity
grid through a subsea cable.
What the O2-X Brings to Tidal Energy
The O2-X is Orbital's next-generation floating
tidal turbine, designed specifically to move from prototype to series
production. Rated at 2.4 MW, it delivers a 20% power increase over the O2.
While the O2 proved the floating tidal concept works, the O2-X is built to make
it commercially repeatable. Lloyd's Register has awarded the O2-X an IECRE
Feasibility Statement, a globally recognized certification milestone that
confirms the design's readiness to move toward serial manufacturing.
The key difference is in the design philosophy.
The O2-X is built as a modular, standardized product rather than a
custom-engineered prototype. It adapts to different tidal conditions through
adjustable ballast, which means the same turbine design can be deployed across
multiple sites without requiring a redesign for each location. Six O2-X units
are contracted for deployment in Orkney through UK Contracts for Difference
agreements. As an evolution of the O2, the O2-X builds on the same floating
platform architecture, tow-to-site deployment method, and blade pitching system
that the O2 has demonstrated in operation.
How the O2-X Aims to Reduce the Cost of Tidal Energy
Through a project called MAXBlade, Orbital is
working to extend the O2-X's turbine blades from 10 meters to 13 meters. Once
complete, these would become the longest tidal turbine blades in the world,
increasing the combined rotor swept area to over 1,000 square meters, a 70%
increase over the current configuration. Longer blades capture more energy per
rotation, and according to the project team, blade length is the single factor
with the greatest impact on reducing the cost of tidal energy.
The MAXBlade project is funded by the EU and UK
Research and Innovation. The extended blades will undergo two years of
real-world testing at EMEC in Orkney. This blade scaling is exclusive to the
O2-X production roadmap and was not part of the original O2 design.
A Global Deployment Pipeline Taking Shape
Orbital's deployment plans extend beyond
Scotland. Fisheries and Oceans Canada has authorized the installation of up to
three O2-X turbines at the Fundy Ocean Research Centre for Energy in the Bay of
Fundy, home to the highest tides on Earth. This is the first tidal project to
proceed under Canada's revised permitting approach, which allows developers to
start with a single device and add more as environmental data is collected.
Orbital has partnered with Canadian developer Eauclaire Tidal for this project.
The company recently secured €8 million in new
funding led by PXN Ventures and supported by existing shareholders including
Scottish Enterprise, bringing total funding to approximately $19.4 million.
Additional plans include the 30 MW Westray Firth project near EMEC, which would
use roughly 12 Orbital turbines and represent a true commercial-scale tidal
array. Orbital is also leading the EURO-TIDES project, which aims to develop a
9.6 MW array integrating floating tidal turbines with wind power, battery storage,
and green hydrogen production.
Where Tidal Energy Stands in the Broader Renewable Landscape
Tidal energy remains a small segment of the
global renewable energy market compared to solar and wind. European tidal
stream generation currently produces a fraction of what offshore wind delivers
annually. However, tidal energy offers something that solar and wind cannot
guarantee: scheduling certainty. Tides arrive on a predictable cycle regardless
of weather, season, or time of day, which makes tidal power a potential
complement to intermittent renewable sources rather than a competitor.
The primary barrier to wider adoption has been
cost. Building, installing, and maintaining turbines in harsh marine
environments is expensive, and the technology has not yet reached the
production volumes needed to bring costs down significantly. The O2-X's move
toward standardized, series production is intended to address exactly that
barrier. Whether tidal energy scales beyond demonstration projects into a
meaningful share of the global energy mix will depend on whether devices like
the O2-X can prove that reliable, repeatable manufacturing drives costs low
enough to compete. The contracted pipeline of six turbines will serve as one of
the first real-world tests of that proposition.
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