Silver Nova’s propulsion system consists of LNG, hydrogen fuel cells and battery power (source: Meyer Werft)
How Silversea Cruises’ latest ship is on the path to being climate neutral
Silver Nova combines some of the most innovative new technology and alternative fuels seen yet on a cruise ship.
LNG, hydrogen fuel cells and battery power have been combined, making this cruise ship a first of its kind.
Construction of 243-m Silver Nova, with accommodation for 728 passengers, began in November 2022 at Meyer Werft. Dual-fuel engines use LNG as the main fuel with a 4-MW fuel-cell system complementing the LNG engines.
As Meyer Werft communications manager Florian Feimann explains, “Together with Silversea Cruises and the Royal Caribbean Group, we set ourselves the task of developing a new class of ship that combines luxury with environmental friendliness and efficiency. We were already experienced with LNG on cruise ships and could therefore already deliver this technology. In addition, a fuel-cell system was to be installed on board to remain emissions free with a self-sufficient energy supply in port. Because we have LNG on board anyway, a reformer from LNG to hydrogen, with which the fuel cells are operated, was to be developed as part of a research project. To compensate for the inertia of the fuel cells and further increase efficiency, we decided to add a battery system.”
Silver Nova, which was handed over by Meyer Werft in July to its owner Silversea Cruises, the ultra-luxury brand of Royal Caribbean Group, is the first of two Nova-class cruise vessels. Silver Ray is under construction and due for delivery next year.
New standards
“We are delighted with Silver Nova, a ship where new standards will be set on the path to a climate-neutral cruise. With the drive system, a combination of LNG, fuel cells and batteries, the ship sports the best possible measures to reduce emissions,” says Meyer Werft chief executive Jan Meyer.
Explaining the system in more detail, Mr Feimann says, “The use on cruise ships has some special features, so this hybrid solution is the best. We can use the battery system to absorb load peaks from the LNG engines or use the engines to charge the batteries during underloads. At the same time, the fuel cells supply enough energy to power the ship’s hotel operations. In this way, the overall system always operates optimally.”
Silver Nova can lie in port emissions-free with this propulsion concept. “We have developed this concept specifically for cruise ships, because LNG is now widespread and available, so we save ourselves another fuel on board. In addition, the hybrid solution fits perfectly with the sailing profile of a cruise ship with port berthing times during the day and sailing time overnight,” adds Mr Feimann.
In addition, the batteries mean that by absorbing peak loads, the overall efficiency of the vessel is increased, significantly reducing fuel consumption.
The supplier of the main engines – which incidentally hold a world record in the Guinness Book of World Records for their efficiency – is Wärtsilä, the supplier of the fuel-cell system is Freudenberg e-Power Systems, and the battery system came from Xalt Energy, which also belongs to Freudenberg.
But it is not just the fuel systems deployed on the ship which are environmentally friendly. There are other green and energy-efficient features.
Mr Feimann comments, “We have made the whole ship extremely efficient. This includes heat recovery and the use of waste heat from the main engines, for example to heat the pools or to convert the heat into cold and use it for the air conditioning. We have also optimised the hull shape with a lot of effort.”
And for the first time, the shipyard has installed a so-called micro auto gasification system, which reduces onboard waste volume, resulting in lower incineration emissions.
In addition, the ship class is also projected to achieve an energy efficiency design index (EEDI) rating of approximately 25% better than applicable IMO requirements.
World firsts
A world first on board Silver Nova is the Meyer energy management system, which was developed by the shipyard’s company Alfred Maritime. “We use it to analyse the ship’s operation and make recommendations for the most efficient operation of the systems on board,” explains Mr Feimann.
For the first time at Silversea, the Nova-class ships will feature a horizontal layout and an innovative asymmetrical design, with public spaces and suites spanning the entire length of the ship. As a result, guests experience an unprecedented open design of the ship to the water and to the destinations.
The new ship will offer guests all-new outdoor spaces for an openness to the destination, with a reimagined, outward-facing pool deck; an al fresco dining area; and a sky bar that offers panoramic views from the ship’s aft.
“Silver Nova represents the next iteration of Silversea’s unique take on luxury, with an entirely new design approach that will enhance our guests’ cruise experience,” says Silversea president and chief executive Roberto Martinoli. “With its outward-facing, asymmetrical layout and all-new outdoor venues, Silver Nova will offer our guests a brand-new way to connect and engage with each destination. Moreover, with its groundbreaking environmental credentials, Silver Nova will strengthen our position at the forefront of sustainable cruise travel.”
Silver Nova’s asymmetrical design has enabled the creation of a reimagined pool area and outdoor venues on decks 10 and 11. “Each space places emphasis on the destination, with panoramic views that connect guests with the world beyond,” says Silversea.
At the steel cutting of Silver Ray last year, Mr Martinoli summed it up well as he said, “The second vessel in our pioneering Nova class, Silver Ray – and its sister ship Silver Nova – will strengthen our leadership in ultra-luxury cruising, introducing advancements in engineering that support our mission to showcase the world to our guests, and to do so mindfully, respectfully, and in unprecedented comfort.”
