ALS technology specialist’s fast-growing customer base is realising significant cuts to fuel consumption and GHG emissions
Faced with the uncertainty surrounding costs and availability of future fuels and mounting pressure to comply with increasingly stricter targets for decarbonisation, prioritising ship design efficiency will be key for shipowners and operators as they look to keep their vessels economically operational in coming years. Perhaps the biggest energy cost to a vessel’s operation is the frictional resistance between the hull and the water, and here the air lubrication system (ALS) has emerged as one of the leading options for reducing fuel consumption and, consequently, carbon dioxide emissions.
According to figures from Lloyd’s Register, air lubrication now sits in the top three (along with bow enhancement and hull fins) of most popular hull-related emissions reducing and fuel saving technologies and its stock continues to rise, with a significant number of orders for the technology announced this year. Amongst those orders has been a landmark deal for UK-headquartered Silverstream Technologies; the company has reached over 200 orders for its patented air lubrication system with a contract to install the technology on board 18 new LNG carriers to be built in China.
“Our Silverstream System is fast becoming a standard choice on newbuild vessels and a leading retrofit option,” Noah Silberschmidt, Silverstream’s founder and CEO, tells TNA. He adds: “Surpassing over 200 orders is a significant milestone for us. It demonstrates the tangible emissions and cost savings we have delivered for shipowners and operators.”
Launched in 2010, Silverstream Technologies’ growth journey is closely entwined with the upward trajectory of air lubrication as an energy-efficiency measure for vessels. The company completed its first installation in 2014 – a retrofit for Shell on the MR tanker Amalienborg that resulted in a reported 4.3% net savings in fuel consumption and emissions – and in the years since has played a high-profile role in the scaling and commercialisation of air lubrication technology across the maritime sector. Along the way, the firm has garnered an impressive list of awards and accolades, including the prestigious Royal Institution of Naval Architects-QinetiQ Maritime Innovation Award in 2021, and earlier this year featured in the Financial Times’s FT 1000 list, where it was named among the top 25 fastest growing companies in Europe and third fastest in the UK.
In 2022 it opened a new office in Shanghai, bringing it closer to one of shipping’s key markets and powering up the company’s export arm.
“The past 14 years have been a remarkable journey,” says Silberschmidt. “From 12 orders in 2020, we now have 87 ships on the water and, if you look at the oil and gas sector, I don’t think it’s possible to name one oil and gas major that we are not working with. We are retrofitting with a lot of these companies for LNG carriers, with around 60 contracted to date.
“We also have about 100 container ships, around 30 car carriers, some CO2 carriers under construction in China for the Northern Lights project, a number of wet and dry bulk carriers, and of course cruise ships. It doesn’t matter which segment you look at, we will have a system for it and orders from some of the leading players, many of which are repeat customers.”
The Silverstream ALS fundamentally changes the interaction between water and a vessel by shearing air from air release units (ARUs) in the hull to create a uniform carpet of microbubbles that covers the full flat bottom of a vessel. As a result, frictional resistance is decreased, cutting average net fuel consumption and greenhouse gas (GHG) emissions by a verified 5-10%, depending on a ship’s operating profile.
Over the total lifetime of all contracted vessels, Silverstream estimates that its air lubrication technology will save its current customer base almost US$5 billion in fuel costs and prevent more than 20 million tonnes of CO2. Additionally, this CO2 reduction is projected to save approximately US$2 billion through existing carbon tax systems.
“I think it’s clear that all owners and charterers should think about efficiency from the start,” notes Silberschmidt. “When you design a newbuild you want it to be a long-lasting asset, and today that means incorporating a variety of clean technologies into the design so that you burn less fuel and reduce your emissions. And of course, I think a well-designed vessel will incorporate Silverstream’s air lubrication.”
He adds that to comply with regulations such as EEXI and CII, air lubrication is becoming increasingly important for retrofit application, a market that now makes up 20-25% of Silverstream’s orderbook.
Optimisation through advanced data analysis
Another milestone in Silverstream’s journey came this summer with the launch of a new Global Operations Centre near the Port of Southampton, a key hub for many of the company’s customers including Carnival Corporation, MSC and Maersk. Additionally, the centre is close to the Maritime Engineering School at the University of Southampton, a long-standing partner of Silverstream. As well as enhancing Silverstream’s operational capabilities and supporting the existing fleet, the new hub is equipped for further R&D on the company’s Control and Monitoring System (CMS).
“While we first started to experience sea trial analysis in 2014 with Shell, today, through our CMS, we are getting an incredible amount of data,” says Silberschmidt. “With 80-plus vessels in service, we’re looking at around 20 million data points a week, so are putting a lot of resources into how we can handle this data in the best way possible, which is important from a lifecycle perspective. Good data utilisation gives us a better understanding of our air lubrication technology and provides valuable insights that can influence a ship’s overall performance.”
He adds that the implementation of advanced data analysis techniques such as machine learning and artificial intelligence, in combination with environmental and operational inputs such as weather, water conditions, draft, speed, load and route, has the potential to unlock even greater performances from the Silverstream System. “Being able to respond to these factors will enable the system to operate with maximum efficiencies,” Silberschmidt explains.
He continues: “Currently, we have 26 people at Silverstream – that’s around 20% of our workforce – in our data and vessel performance team looking at how we can drive further value for our customers.”
A multi-purpose tool
While much of the focus on air lubrication falls on emissions reduction and fuel efficiency, the technology is also contributing to a healthier ocean environment in a quieter way. Noise pollution, or underwater radiated noise (URN), from the maritime industry is a key sustainability issue for the International Maritime Organization (IMO) and a study last year by the University of Southampton, sponsored by the International Chamber of Shipping, suggested that ALSs could help reduce vessel noise by more than 10dB.
“We have been looking at URN for some years and firmly believe that the air bubbles from our system help screen noise emissions both from the hull and the propeller,” says Silberschmidt. “It’s an aspect of the technology that a lot of our customers are interested in, especially if their vessels are going into areas where there are special regulations for marine life.”
He adds that Silverstream has been particularly working with cruise ship owners and operators to investigate the potential positive impact of air lubrication on URN with successful results, and that the company is keen to collaborate in further in-depth research to help demonstrate the effectiveness of air lubrication as part of shipping companies’ URN management and mitigation plans.
Silberschmidt points to air lubrication’s effect on biofouling as another associated benefit of the technology, and also another area for further study. “We have had ships in service for 10 years now, and when the ships come into drydock we never see any fouling in the area we are lubricating,” he says. “Part of the reason customers come back to us again and again is that since installing our system they don’t need to do hull cleaning on the flat bottom and have also stopped polishing the propellor.”
The hardness of the microbubbles produced by the ALS may be one reason that microorganisms are being discouraged to take hold, suggests Silberschmidt. “We don’t know for sure as it’s not scientifically proven, but we believe that’s what’s happening,” he says, adding that Silverstream has engaged with two major ship paint and coating manufacturers to get a better understanding of the effect and additional research will likely be carried out at the company’s new Global Operations Centre.
Silberschmidt concludes that air lubrication has become a compelling multi-purpose tool to protect the environment and support shipowners and operators through the regulatory and commercial implications of shipping’s decarbonisation challenge, and that evolving market drivers such as carbon taxes and the introduction of costlier low energy density alternative fuels could see thousands of vessels fitted with the technology over the coming decade. “They say the cheapest fuel is the fuel that you don’t use at all, so it doesn’t make sense not to look at clean technologies like the Silverstream System,” he says.
Noah Silberschmidt, Silverstream founder and CEO
