Cruise Ships

This makes cruise ships more environmentally friendly

The eco-balance of cruise ships is bad. On the high seas, they burn tons of heavy fuel oil, and during laytime in the harbor diesel fumes pollute the air. How could the ships get cleaner?

Since the end of 2018, the cruise ship "Aida Nova", which is mainly powered by liquefied natural gas, is operating on the oceans. With the ship high hopes for the environmental balance of luxury liners are connected. But liquefied natural gas (LNG) is also a fossil fuel. When it is burned, however, significantly fewer pollutants are released.

Cruises are far from sustainable. How much the exhaust fumes from the chimneys of ships pollute the air, Uwe Jacobshagen makes clear in the chapter National Legislation from the book Environmental Protection and Dangerous Goods Transportation for inland and maritime shipping. There, the Springer author writes: "Ship emissions contain various types of pollutants: Sulfur oxides (SOx), nitrogen oxides (NOx), carbon dioxide (CO2), soot particles, particulate matter, as well as heavy metals, ashes and sediments."

The cause of the emissions lies mainly in the use of the fuel. Most ships are operated with heavy fuel oil and marine diesel, whereby the heavy oil as a waste product of petroleum processing is particularly polluting, as Springer-author Wolf-Rüdiger Bretzke writes in the chapter Strategies and Concepts for the Promotion of Sustainability from the book Sustainable Logistics. Greener than ship diesel. But here, too, sulfur and nitrogen oxides are produced during combustion.

Cruise ships also burden passengers and cities
What aggravates the environmental impact: Cruises are becoming increasingly popular. In 2017 alone, 25.8 million people went on a cruise around the world, as Springer author Ralf Witthohn explains. This is reflected in the increasing sales of the cruise industry. In 2015, their turnover had already risen to almost 40 billion US dollars, as Witthohn writes in the chapter Cruises from the book Transport, work and recreation at sea. Ascending trend. And with each additional ship, of course, the pollution also increases.

Especially for the passengers and the crew on board, who are exposed to a high concentration of air pollutants, as reporters of the ZDF consumer magazine "Wiso" found out in 2017. During a voyage aboard the "Aida Sol" from the Canaries to Madeira, samples taken with a mobile ultrafine particle measuring device yielded up to 475,000 particles per cubic centimeter of ambient air. Actually, with clean sea air, values of just 1,000 particles per cubic centimeter would be expected, as the German Nature Conservation Union (Nabu) explains.

How much shipping pollutes not only the sea air, but also the cities is shown in a recent study by the European umbrella organization and the Nabu partner organization Transport & Environment (T & E). Accordingly, popular destinations such as Barcelona, Palma de Mallorca and Venice are the cities most heavily polluted by cruise liners in Europe. Most of the air pollutant emissions are apparently attributable to the fleet of the Italian industry giant Costa Crociere, closely followed by MSC Cruises (Switzerland). For the report, the emissions of cruise ships in European port cities in 2017 were determined and evaluated.

No mobile power generators in the Port of Hamburg
With Hamburg, the first German port ranks in eleventh place in the European comparison, the small Warnemünde landed in 14th place out of a total of 50 evaluated port cities. The dimensions of air pollution also became clear in the study: According to this, the cruise ships calling at Hamburg in 2017 caused more than one and a half times more sulfur oxide emissions than the almost 770,000 cars registered in the Hanseatic city. Sulfur oxides harm human health and lead to acidification of soils and waters , According to the study, the nitrogen oxide emissions of the ocean giants corresponded to around twelve percent of the car-related exhaust emissions.

In particular, the diesel-powered ship generators, which ensure the power supply on board with the main engine switched off in the harbor, generate considerable amounts of pollutants, as Springer author Oliver Lieber in the chapter Investigation of the conflict between urban developers and port management in Hamburg from the book port versus city knows. An alternative would be a shore power during the laytime in the harbor. Such a supply in addition to the existing shore power system for cruise ships at the Hamburg-Altona terminal had also been planned by the city of Hamburg. She actually wanted to buy environmentally friendly, mobile power generators, so-called Powerpacs. These are powered by LNG to power the ships. Now it became known recently that the project is on ice because the ships lack the necessary connections for external electricity. The shipping companies apparently do not invest in the conversion. The problem with ship exhaust gases therefore remains for the time being. Norway shows that countermeasures are well possible. A ban on entering fjords for ships with an internal combustion engine was recently introduced. However, this will not take effect until 2026.

Cruise with sulfur
The T & E study can also assign pollution to specific providers. The study shows that the world's largest cruise group Carnival Corporation emitted almost ten times more sulfur oxides along Europe's coasts in 2017 than all 260 million cars in Europe together. The Carnival Group includes subsidiaries such as Aida Cruises, Costa Cruises or the Cunard Line. The second largest cruise group, Royal Carribean Cruises, which includes the German TUI Cruises, ranks second with four times higher sulfur oxide emissions, the study said.

Criticism of the analysis comes from the World Cruise Industry Association, the Cruise Lines International Association (Clia), because the study results were "published without an academic exam or peer review". The ranking is based solely on assumptions and not on measurements, according to a statement.

Environmental regulations put pressure
Nonetheless, the industry must work hard on emission-free drives if it wants to have a future. By incorporating scrubbers ("scrubbers"), for example, the sulfur emissions from the exhaust gases can be cleaned. However, Sönke Diesener, Nabu shipping expert, demands more: "Instead of using the toxic heavy oil now, the fleet has to be converted to higher-quality fuels in combination with particle filters and nitrogen oxide catalysts."

The world's increasingly stringent environmental regulations are in a hurry, too: in the North and Baltic Seas, ships that do not reduce the sulfur content in the exhaust gases to 0.1 percent through appropriate filters have long been banned. As of 2021, stricter rules for the emission of nitrogen oxides must also be observed in the North and Baltic Seas. From 2020, sulfur limits in marine fuels will be 0.5 percent on all seas and 0.1 percent in emissions control areas and European Union ports, according to Springer author Harald Zeiss in the chapter on environmental protection in the cruise industry from the book CSR and Tourism , De facto, according to Zeiss, it is a heavy oil ban.

So the shipping companies want to reduce emissions
Some cruise line providers are already under pressure. The Norwegian shipping company Hurtigruten plans to operate at least six biogas and battery powered ships by 2021, combined with LNG. The biogas is to be obtained from fishery waste and other organic residues. As early as 2019, the Hurtigruten fleet is to receive a new flagship: the MS Roald Amundsen. The expedition ship with hybrid drive relies on a combination of combustion engine and electric motor.

And fuel cells could also play an important role in the industry in the future. For example, the RiverCell 2 project since April 2017 involves the development and testing of a hybrid concept for the total energy supply of a river cruise ship with fuel cells and alternative fuels. The project will run until September 2019. Within the framework of e4Ships, fuel cell systems will be developed, which will enable energy supply on board ships under sea conditions. With Royal Caribbean Cruises, one of the industry giants now wants to switch to the fuel cell and has two fuel-cell powered vessels built at the Finnish subsidiary of Meyer Werft, Turku Oy. Aida also deals with the potential use of fuel cells or batteries. If you already want to drive with a fuel cell ship, you have to go to the Baldeneysee near Essen. Since August last year, the MS Innogy has been using a methanol fuel cell, which was developed as part of the Pa-X-ell project.

LNG no salvation, but currently the cleanest
But the area coverage of the fuel cell is still a vision of the future - as is the emission-free cruise. LNG alone does not achieve this goal, but it is the cleanest fuel at the moment. Even if the source of natural gas has to be considered here, fracking gas, for example, would significantly reduce sustainability compared to conventional fuels. The same is true of methane slippage, ie methane leakages that can occur in running gas engines or along the LNG process chain. Methane has a global warming potential over 21 times that of CO2. In addition, the infrastructure for LNG is still poor.

Even if LNG is not a savior, the fuel is after all an important step away from the environmentally harmful heavy oil. The initially mentioned "Aida Nova" has also taken the course towards LNG. And for the next few years shipping will probably be determined by LNG. More than a third of all newbuildings, a total of 25 ships, will use LNG as the main propulsion fuel, the Clia reports. For example, the Costa Smeralda is scheduled to go into operation in October 2019; she will then be the first Costa ship operated with LNG. A second ship, the sister ship of the Costa Smeralda, should be delivered in 2021.