Biofuels can make ships surprisingly low-emission.

Background: This article results from independent journalistic work. The situation is “ongoing,” and I will keep track of it. The ships depicted in the images are not those of the companies mentioned in the text but are generated by artificial intelligence. ©Kyösti Vaara. Media citations must include the source and the URL of this webpage’s homepage.

Ferry routes between Sweden and Finland have been the weakest link for travelers traveling from Finland to Europe by land – now biofuels could reduce emissions from a ferry trip to a few kilograms.

In 2026, data on CO2-equivalent emissions from LNG ships will be available. These ships operate between Finland and Sweden. According to preliminary data, there is no major concern. Ship emissions from Turku to Stockholm can be high. However, mixing biodiesel with LNG reduces them to just a few kilograms. Passengers will have to “buy” biodiesel for a small additional fee.

The future of LNG ships was clouded a few years ago when concerns arose about their methane emissions into the atmosphere. Viking Line’s Glory and Grace, which operate on the Turku-Åland-Stockholm route, are both LNG ships.

Background

LNG is an abbreviation for Liquified Natural Gas.

Methane is 25 times more potent a greenhouse gas than carbon dioxide. However, it also evaporates quickly from the atmosphere. In addition, ships can emit nitrous oxide, or laughing gas, which is an astonishing 300 times more potent as a greenhouse gas than carbon dioxide.

Viking Line’s Sustainability Manager Dani Lindberg says that in the near future, shipping operations will be regulated by the FuelEU marine regulation. This sets reference values for emissions from different fuels.

– The regulation sets a default value of 3.1% methane emissions for Grace and Glory’s engines. However, our measurement results actually show lower figures, significantly lower in the case of Glory. We are still waiting for clarification from the Commission on the measurements and the use of the results in light of the regulation. We expect this guidance by the autumn.

Background

The 3.1% figure refers to the proportion of non-flammable fuel in the total mass of the fuel. Simply put, 3.1 grams of fuel from every 100 grams doesn’t ignite in the engine. Instead, it escapes with the exhaust gases. Unlike oil, gas is lighter than air, which causes escape. The legislator has set different runaway percentages for various engine types. This depends on the technology and fuel system pressure. The percentage given for Viking Line’s engines is unclear.

Biofuel is the customer's choice

Lindberg states that last year the emissions per passenger using LNG fuel on the Viking Glory during the Turku-Åland-Stockholm route were 46.35 kg CO2 equivalent. This and all other similar CO2e figures take into account the emissions across the fuel’s entire lifecycle. In maritime transport, this is referred to as the Well-to-Wake (WtW) perspective.

– However, if a passenger chooses biofuel as their energy source, the emissions drop to only 2.33 kg Co2e, says Lindberg.

Thus, emissions decrease to a fraction of the original amount. The emissions for the Viking Grace on the same route are slightly higher at 47.09 kg CO2e for LNG and 5.48 kg CO2e for biofuel.

– This assumes a baseline of 3.1% methane emissions, and the emissions per person have been calculated according to the ISO 14083:2023 standard.

Background

CO2 equivalent, or CO2e, measures how greenhouse gases affect the climate. In this case, we convert the methane and nitrous oxide emissions into carbon dioxide units. Then, we add these to the carbon dioxide emissions. The Well-to-Wake calculation includes emissions from production and distribution. It doesn’t only count emissions from fuel use. In other words, it is a very comprehensive way of presenting the amount of emissions.

Biofuel is twice as expensive for the shipping company

It feels a bit strange that a passenger on a ship has their own fuel onboard. However, this is not the case, as the company calculates the energy needed to transport one passenger on an annual basis. When the customer chooses to travel with biofuel, the company converts this energy amount into biofuel, which is ordered from the same supplier that brings the LNG. A mixture of LNG and biofuel is created in the tank.Biofuel or Bio-LNG or LBG is produced from food waste, among other things.

– Biogas is ISCC certified, and we receive a sustainability certificate for each batch, meaning we can see the raw materials used in production and the emissions resulting from it. Biogas is physically refueled onto our ships, so it’s not a matter of simply buying certificates. The frequency of refueling depends on demand, Lindberg says.

The emission reductions from biogas are so significant that they warrant verification. Gasum, the supplier of biofuel for the ships, stated on their website a year ago that climate emissions decrease by nearly 90 percent on board the Viking Glory and Viking Grace compared to the normally used liquefied natural gas, or LNG. The figure now reported by Viking Line indicates about a 95 percent reduction. I requested a comment from Wärtsilä, the manufacturer of the engines. They advised believing Viking Line’s figures. I also sought comments from two biofuel experts. I did not receive responses to my inquiries.

Passengers can reduce their emissions financially. The additional charge is currently €2.30 per passenger on the Turku-Stockholm route. For the company, LNG is cheaper than biofuel.

– Roughly speaking, we can say that the bioalternative is twice as expensive as fossil fuel.

With little money, great climate benefit

Personal emissions therefore decrease to a small fraction with just a few euros. This feels significantly better than compensating for emissions, as the traveler acts as the buyer of biofuels. On the other hand, the emissions from the ship that the traveler is on may be quite different, but in the long run, the payment reduces emissions.

The distance from Turku via Åland to Stockholm is about 320 km, which is twice the distance from Helsinki to Tampere by train, for which the EcoPassenger emissions calculator gives an emission of 6.6 kg. Therefore, Lindberg’s figure of 2.33 kg is so low that it clearly falls below the equivalent train journey emissions.

There is often discussion about how emissions should be divided between the ship’s passengers and cargo. The allocation between passengers and freight comes directly from a standard. In practice, the total emissions caused by the ship’s annual consumption are allocated based on weight between passengers and freight according to the new ISO 14083 standard, with about 60-70% of emissions allocated to freight.

To ensure that ships run primarily on biofuels, meaning with low emissions, all passengers and cargo providers must pay an additional fee. Several thousand passengers have already opted for biofuels.

-We also offer freight the opportunity to be transported with biogas. So far, we have not seen a significant willingness to purchase from the industrial or logistics sectors, Lindberg says.

And what about personal vehicles, vans, buses, motorcycles, etc. being transported by ship?

– We have not yet developed a biofuel option for these units.

Not all Swedish ships are LNG vessels

Tallink Silja Line operates two LNG-powered vessels, MyStar and Megastar, on the Helsinki-Tallinn route. The ferries traveling between Turku and Stockholm as well as Helsinki and Stockholm use low-sulfur marine diesel.

According to the European Maritime Safety Agency’s EMSA open data, the carbon dioxide emissions per passenger on the Turku-Stockholm route are 27 kg. Viking Grace has a corresponding figure of 10.85 kg CO2 per passenger, while Viking Glory’s figure is 10.59 kg CO2 per passenger. This reflects the carbon dioxide emissions of the aforementioned LNG vessels.

Tallink Silja Line has not adopted biofuels. Their benefits would be minimal. The company’s LNG vessel routes are short (Helsinki-Tallinn), and the advantage of biofuels on diesel vessels is smaller. The carbon reduction potential of biodiesel is inferior to that of biogas.

However, efforts to reduce emissions have been made within the company. Communications Director Marika Nöjd states that the company’s CO2 emissions have decreased to less than half over the last 15 years.

-Reductions have been achieved by acquiring two LNG-powered vessels, implementing shore power, updating heating, ventilation, and air conditioning systems on several ships, and replacing the propeller blades with new ones that enhance energy efficiency.

Also, nitrogen and sulfur emissions should be considered

The emissions from Viking Line between Turku and Stockholm, when using only LNG, are just under 50 kg (including carbon dioxide, as well as adjustments for methane and nitrous oxide). The number provided by EMSA for Silja Line on the same route is 27 kg (including carbon dioxide). For Viking Line’s LNG vessels, the EMSA figure is in the range of 11 kg.

Of course, the environmental investments made by Tallink Silja Line influence these numbers, but the reason could also be that the emissions reported by Tallink Silja do not account for the entire life cycle, meaning the Well-to-Wake (WtW) portion of the emissions is missing. WtW includes emissions that come from production, not just from fuel consumption. This encompasses emissions from drilling, refining, and distribution logistics. Additionally, for Tallink Silja’s LNG vessels, methane and nitrous oxide emissions remain a mystery as they only report CO2 emissions.

-The CO2 figures for Viking Line and Tallink Silja Line ships should not be compared directly, as the calculation methods differ. We have repeatedly emphasized this to the European Commission to ensure that the data would be comparable. The calculation methodology should be consistent for everyone. Unfortunately, we have ended up choosing different methods, says Marika Nöjd.

We are now addressing greenhouse gas emissions. It’s important to note that LNG and LBG vessels produce very little nitrogen emissions and practically none that are harmful to health, such as sulfur or particulate matter emissions.

Tagged Biofuels