Meeting decarbonisation targets with optimised propulsion
3 min read
05 May 2021
3 min read
05 May 2021
It’s not often that the twin goals of reducing costs and complying with regulations can be solved with the same solutions, but that’s definitely the case when it comes to energy efficiency. What is often not realised, however, is that the optimum solution is always more than the sum of its parts – and it takes real expertise to put the right components together. Elias Boletis, Director Wärtsilä Propellers and Transmission, explains more.
“With all minds focused on the challenges of decarbonisation, and while we wait for carbon-free fuels to become widely available, the main concern in the maritime industry in recent years has been making vessels as energy efficient as possible,”
explains Boletis. “Until recently, emissions requirements only applied to new-build vessels but from 2023, with the introduction of EEXI, they will be applicable to existing vessels too, meaning many additional owners and operators will be looking
at how best to comply.”
“Increasing propulsion efficiency is central to reducing emissions, and Wärtsilä’s propulsion portfolio is one of the broadest on the market, but the key to optimising energy efficiency isn’t found in individual products,” shares Boletis. “Instead it requires a suite of energy-efficient solutions working together: the right propeller for the vessel supported by many other components, from the shaft, gearbox and auxiliary systems to energy-saving devices that reduce surrounding inefficiencies. To find the right solutions and piece them together in the optimal way for each vessel takes a great deal of expertise.”
A comprehensive approach to tackling inefficiency
“To optimise efficiency, you need to tackle all sources of inefficiency – both those that stem from the propulsion system and those that come from the vessel itself,” explains Boletis. “We can find these inefficiencies using computational fluid dynamics (CFD); for example, examining how water flow before and after the propeller affects propulsion performance. To optimise flow you can reduce inefficiencies with devices such as Wärtsilä EnergoFlow before the propeller, which can improve fuel efficiency by up to 10%, and Wärtsilä EnergoProFin, an energy-saving propeller cap that increases propulsion efficiency by a further 2% by improving water flow after the propeller.”
The best technology – wherever it comes from
“We are not too proud to look outside of our own expertise when it comes to finding the best way to increase a vessel’s propulsive efficiency,” highlights Boletis. “We saw that friction drag on the flat bottom of a vessel can reduce efficiency by as much as 20–30% and realised that by eliminating that we would see a significant reduction in fuel consumption. We are now partnering with Silverstream Technologies to offer their Air Lubrication System (ALS) to our customers, which uses a carpet of bubbles to reduce the friction drag, making vessels more efficient with lower fuel consumption at any given speed. This technology can increase energy efficiency by up to 8%, depending on the vessel type.”
“As the option with the most ‘easy wins’, the current focus is squarely on propulsion efficiency and energy-saving technology.
- Elias Boletis, Director Wärtsilä Propellers and Transmission
“ALS is just one example of how we are partnering with smaller companies to help industrialise their solutions and address the whole marine market,” continues Boletis. “Another third-party solution we have added to our portfolio is Kuribayashi
Steamship Co.’s Gate Rudder, which lowers fuel consumption by at least 5% across a range of vessel types and reduces emissions while minimising noise and vibrations. Having these products as an integral part of our propulsion portfolio allows
us to deliver a complete optimised solution for energy-efficient propulsion to our customers.
Yet another important method to increase overall energy efficiency is wind-assisted propulsion. Many locations around the globe have high winds that are currently not being utilised by vessels but, when harnessed using wind-assisted propulsion technology, they can significantly reduce your total power needs. For example, Anemoi Marine Technology’s Rotor Sails, which are also part of our offering, provide fuel savings of up to 20–25% with multiple rotors on routes with moderate to high wind intensity. This is not only good news in terms of operating costs, but also contributes to decarbonisation efforts.”
A unique solution for every vessel
“With access to the best solutions on the market, we can help to find the optimal combination of solutions for a particular vessel or owner,” Boletis explains. “We can propose alternatives that consider both the efficiency gains
and the ability of the owner to finance the solution, allowing the customer to choose the package that best suits their circumstances.
“We serve the needs of the whole market, from very large container ships to smaller vessels like fishing boats and research vessels – and we always optimise our solutions to the owner’s exact needs. We might take a controllable pitch propeller and add EnergoProFin and Rotor Sails, for example – in combination the savings in energy consumption can be over 20%. Whatever the customer’s requirements, we will try to help.”
All the right tools for the energy efficiency job
“One advantage we have over our competitors is the fact our propulsion technology has been developed over decades and has a lot of history and expertise behind it – and we still optimise and improve our solutions all the time,” points
out Boletis. “On top of this proven foundation we have built a very large portfolio of energy-saving devices, which enables us to bundle a wide range of solutions into one optimal package. Because we can integrate ship design, propeller
design and all our additional products, the owner or shipyard has just one party to deal with – and a guarantee that all the technology will work optimally together.”
“We use many different techniques to accurately configure the right solution, from OPTI Design, CFD and hydrodynamics to environmental and operational data,” continues Boletis. “We always start from our robust baseline of products which serve the whole market, but the magic comes from how we combine them with the other solutions and energy-saving technology at our disposal. We aim to become a true partner to our customers, because in harsh marine environments things can always go wrong and if they do, you need to act quickly and in the right way. We always try to help our customers even without a financial pre-agreement; our priority is to do everything we can to solve their problem. Finally, and perhaps most importantly, at the heart of Wärtsilä is our people and their passion and expertise – we have a highly educated and experienced workforce that has stayed with us for many years.”
Energy Saving Technologies
Winning moves on the journey to decarbonisation
“As the option with the most ‘easy wins’, the current focus is squarely on propulsion efficiency and energy-saving technology – and, with fast returns on investment, there are significant savings to be made. Whatever your vessel or operating profile, with our high-performance propellers as the firm foundation of our offering, we can use our experience and expertise to put together a package of energy-saving technology and devices that maximise your savings and help you meet the challenges of decarbonisation,” concludes Boletis.
Learn more about Wärtsilä energy saving devices.
Watch our webinar on Propulsion energy saving technologies.