Introducing GT Green Technologies: developing the future of wind propulsion

As the shipping industry makes the transition away from fossil-fuels to more sustainable, less carbon-based, operations, there are a number of options available. Wind propulsion is one such solution that utilises wing-like sails to generate forward thrust, thus reducing fuel consumption and carbon emissions.

While there are numerous wind propulsion companies on the market, GT Green Technologies has something special up its sleeve: the generation of the highest thrust coefficients in the industry. This company is one of eight PortXL’s 2023 cohort of start-ups in addition to being the winner of the Maritime UK Startup of the Year award. In this interview, GT Green Technologies CEO George Thompson talks about how his company is installing this technology ‘AirWing™’ in modular and scalable units that provide 10-30 per cent fuel savings.

Why did you establish GT Green Technologies?

After looking at existing wind propulsion providers for commercial shipping vessels, we saw that a lot of these systems were large and therefore had a big impact on the operations of the vessel. GT Green Technologies has developed a product in answer to this problem: producing a large amount of thrust from a far more compact and lightweight unit.

So this was the birth of the AirWing?

Yes – we found a completely new way to control the boundary layer airflow, which had never been done before for wind propulsion systems. We adapted the method, optimising the shape to generate thrust coefficients that are the highest in the industry. Compared to other systems, the AirWing is smaller but produces the same amount of thrust. This is what it ultimately boils down to: the ship-owner having improved fuel savings with a minimum impact on the ship.

Has this technology been validated?

All the results have been validated by an external subcontractor, SABE Fluid Dynamics, known for their work on the America’s Cup and Formula 1. They have also helped us with shape optimisation for improved performance. Furthermore, we recently received confirmation that the AirWing is class-approved by Bureau Veritas, which is a massive stamp of approval.

Can we talk a bit about the technical specs of the AirWing?

The smallest AirWing is 20 metres high and eight metres wide. This will fold away to a four-metre section when stowed away. We are designing and manufacturing them in modular sections so that we can very quickly scale up to larger 30 and 40-metre versions. This modular method also means we have greatly decreased the downtime and cost of installation – a critical piece for uptake of this technology.

Wind conditions are constantly changing. How does the AirWing deal with this?

The AirWing can rotate 360 degrees and we can adjust things like the angle of attack, camber and flow control in order to optimise performance in changing conditions. All of these adjustments are fully automated: sensors take the input of wind characteristics, and then the optimum configuration of the AirWing is set automatically.

Looking at the commercial shipping sector, what size of ship could use an AirWing?

The 20-metre AirWing would be suitable for a ship between 100 to 180 metres. In fact, our first installation – planned for 2024 – will be on a 130-metre general cargo vessel. The larger units are suitable for longer ships; up to around 250 metres long.

And how many AirWings could you install on one ship?

It’s very dependent on the type of vessel and its cargo. An important point is that many ships have quite a lot of deck gear – cranes, hatches, mooring equipment etc – so there is not a lot of space for wind propulsion. But because the AirWing has such a high thrust coefficient, we can really maximise the space that actually is available.

What kind of fuel savings does the AirWing provide?

Depending on the specific route and ship, we predict fuel savings of between 10 and 30 per cent. This means that a ship-owner could see a return on investment within two to four years. And because this is an easily retrofitted technology, shipowners and operators can realise the benefit now on their existing fleets. The AirWing will also have a very significant part to play reducing costs over the long term as more and more high priced alternative fuels enter the industry.

What do you want to achieve by being part of the PortXL program?

The main thing that we would like to achieve is access to industry; making important contacts throughout the commercial shipping industry, including shipbuilders and suppliers.

The Rotterdam Maritime Capital of Europe region is heavily investing in maritime innovation. PortXL, located in Rotterdam, is the world’s first port accelerator and is unique in its kind, with a global network of leading companies and experts. Start-ups and scale-ups are guided during the development of their product and the growth of their company via an intensive programme.

Click here for more information on the development programs of PortXL.