There are twice as many scrubbers in the passenger ship segment compared to the overall shipping market, with another surge in orders expected once the sulphur cap comes into force
Passenger ships were among the first to install scrubbers ahead of the stricter emission control areas in Europe coming into force in 2015. This regulation laid down that EU nations should ensure ships in the Baltic, the North Sea and English Channel use fuels with a sulphur content of no more than 0.10%.
Passenger ship companies invested in scrubbers when they were a new technology, not much used outside the tanker segment. For instance, in July this year, DFDS celebrated the 10th year of scrubber operation on one of its ships.
DFDS director for environment and sustainability Poul Woodall says installing scrubbers is a substantial engineering project. There are many factors to consider when selecting a scrubber: a separate system, replacing the silencer, inline or other types and so on. “Every ship is unique. Even sister ships are different so your scrubber engineering solution has to be unique and well planned,” he says, in reference to reports of delays and engineering problems in installing scrubbers.
The DNV GL Alternative Fuels Insight database shows that, overall, the number of ships with scrubbers installed in service or on order quadrupled to 3,021 this year compared to 2018. Out of the 3,756 ships with scrubbers in service or on order heading into 2020, nearly 10% are passenger ships, including ropax vessels and cruise. Some 10% of the passenger ship fleet will have scrubbers while the corresponding figure for all ships is likely to be nearly half of that.
Big cruise companies such as Carnival Cruise and Royal Caribbean have installed scrubbers in their fleet. Exhaust Gas Cleaning Systems Association chairman Nick Confuorto says in terms of net scrubber installations, container ships may lead but in terms of coverage within the fleet, passenger ships are number one.
"Ferries do not have the ability to switch fuels. Scrubbers have been the norm in European ferries for a few years now," says Mr Confuorto, who is also the president of scrubber systems supplier CR Ocean Engineering. He adds that while main engines are candidates for scrubbing, some cruise ship operators have installed generator engines with the ability to switch to MGO.
“Every ship is unique. Even sister ships are different so your scrubber engineering solution has to be unique and well planned” Poul Woodall (DFDS)
During 2018 the market for scrubbers "exploded", according to Wärtsilä, the market leader as per the DNV GL database. "Generally speaking, the size and speed of this increase in demand took everyone by surprise. However, as expected, demand has levelled off in 2019 and the market is now more or less where we expect it to be," says Wärtsilä’s director of exhaust cleaning Sigurd Jenssen. Open-loop and hybrid systems take up a major share of the company’s orderbook.
Selecting scrubbers involves a careful consideration of the following factors: engine size/exhaust gas flow, routes, ports and port stay duration, available space on the vessel, drydock timeframes, open loop/closed loop/hybrid system selection, ocean alkalinity and its effect on scrubber efficiency, cruising speed and engine load. Factors such as space, shipowner image and type of scrubber may be more important in the case of passenger ships. Installation time may also be a tighter constraint in passenger ships.
"1 January 2020 is now at our doorstep, so owners and operators should by now have made their decisions regarding compliance with the sulphur regulations. This means a clearer picture of the options chosen is beginning to emerge. We feel that those companies that made an early decision to install EGC solutions are at an advantage, since compliance is now assured, the payback time is set, and their fuel choice has been decided," says Mr Jenssen.
Being early adopters, the scrubber retrofit market in passenger vessels may have run its course for now while the newbuild market is expected to hold its ground. Mr Confuorto says retrofit orders from big companies have started to taper off while others are still coming in.
Scrubber suppliers predict that once the price of low sulphur fuels stabilises in the market, the payback period for scrubbers will turn out to be lower than feared. This would spur another wave of scrubber retrofits including in passenger ships. "For cruise ships specifically, there are plenty of new orders to be won. Opportunities still exist for retrofit projects since some companies have been waiting until the very last moment to decide which option suits them best," says Mr Jenssen.
"Wärtsilä was the first company to achieve class approval for the marine application of an EGC system, so our experience with both cruise and ferry operators is extensive. This leads us to believe there continues to be fruitful opportunities within these markets," he adds.
The first Wärtsilä Q-SOx was installed this year and the company has already sold 160 of these. The largest unit was 70 MW and the smallest has been 20 MW. Q-SOx is claimed to provide a CO2 emission reduction of 7% to 10%, and a reduction in power consumption of 1.5% to 2.5%. 50% of the scrubber body is made from recycled high-grade steel and performance is 45 m/MWh to scrub 0.1% S compliance.
Wärtsilä has sold 400 of its BOTU-M membrane wash water treatment units that treat a portion of the process water before discharging it overboard or to a holding tank. It also targets small particles in process water. Wärtsilä will soon release a new control system designed to fulfil current rules and regulations around the increasing need for cyber security, with the capability to capture data and linking to onshore data collecting and processing equipment.
Mr Confuorto says the scrubber market grew from a North American and European one to a global market. Passenger ship retrofits happen mainly in Europe, the Bahamas and Australia, with very few in Asia. However, almost all non-passenger ships are going to China for retrofits, he adds.
Meanwhile, there have been reports of mounting delays in yards and teething troubles in operating scrubber systems such as acidic corrosion in scrubber discharge pipelines. Mr Confuorto sees several factors at work here. The shipowner often decides to carry out other work when the ship is going to the yard for scrubber retrofit. This extends the time spent in the yard.
Further, the scrubber tower and other equipment has to be engineered into a ship design that did not intend to incorporate them originally. Space constraints are especially severe on passenger ships. Retrofitting projects are usually challenging due to lack of installation space.
Therefore, scrubber retrofits require planning and engineering work prior to the ship entering the yard. While a scrubber retrofit should typically take 1.5 weeks, lack of planning often leads to delays.
A smaller scrubber footprint helps avoid delays, according to Bilfinger. Side entry of the exhaust gas (in contrast to U-type scrubbers) and dry-running capability (eliminating the need for a bypass) help to reduce the footprint, and these are offered by Bilfinger. Working with experienced design companies and shipyards will ensure the retrofitting process is as smooth as possible, say Bilfinger representatives.
"As we head into 2020, 99% of retrofits are being carried out by yards with little experience in that line work. There is a learning curve but this was always expected," says Mr Confuorto, adding scrubber suppliers have enough experience and have learned their lessons. "The tower itself is easy to install. Mostly it takes just a day or two but laying piping, equipment and cables is what is occupying much of the 2-3 week stay in yards now," he adds.
DFDS was an early adopter of scrubbers, installing a scrubber on a roro vessel sailing the Gothenburg-Immingham-Ghent route. Since DFDS’ focus was the North Sea which was going to see the sulphur mandate in 2015, the company wanted to study scrubbers through an early adoption on a ‘pilot vessel’.
Over three years of operating the ship, Mr Woodall reports learning what to do and what not to do with scrubbers. Dealing with corrosion in scrubber discharge pipelines was among the lessons learned from the pilot, he adds, referring to reports that scrubber discharge pipelines in recent retrofits have leaked or developed cracks due to the acidic content of the discharge water. DFDS decided to go for glass reinforced epoxy pipelines for its scrubber lines, as a best practice, and that decision has turned out to be correct, he said.
Mr Woodall says DFDS’ decision in favour of scrubbers was a response to the nature of its fleet and focus in geographic coverage. “In addition to passenger ships, we run a liner service. We know which port we will call on ahead of time and how much time we will spend on the sea. All this was important in our decision for 2015,” he says, adding every shipping company has a different set of factors to consider.
Regarding the price differential between low sulphur and heavy fuel oil, he says his crystal ball is as accurate as anyone elses. “As demand picks up and shippers start ordering the fuel, we will know how expensive the new fuel will be although what we know with greater surety is that each fuel batch could very well be different in terms of properties,” he adds.