The mass balance principle – a method that makes it possible to blend fossil-free and fossil fuels while still counting them as green on paper – can increase the use of biogas and contribute to the transition of the shipping sector. This is shown by a prestudy carried out within the Swedish Transport Administration’s industry program Sustainable Shipping, which is run by Lighthouse.

The climate transition in shipping is driven by both voluntary initiatives and binding regulations that steer the industry toward lower emissions and more renewable fuels. As its title reveals, the pre-study report Voluntary Climate Targets and Their Impact on the Use of LBG in Shipping focuses on liquefied biogas and voluntary climate targets. Interest in both has increased in recent years.

“Many Swedish companies are affiliated with voluntary climate targets, such as the Science Based Targets initiative (SBTi). Of course, this is about wanting to lead the way and seeing a competitive advantage in working with sustainability issues. These voluntary climate targets have objectives that are aligned with the Paris Agreement, while legislative and mandatory targets often lag somewhat behind,” says Desirée Grahn at IVL Swedish Environmental Research Institute, who led the pre-study.

Another key concept in the pre-study is the mass balance principle, a method that can be used to enable the reporting of climate benefits in systems where both renewable and fossil fuels are used.

“It works roughly the same way as green electricity. This means that, for example, you can operate a vessel on natural gas and count it as a green transport on paper because somewhere else in your fuel pool or system you are using biogas. This can be an important enabler, since it is not possible to bunker biogas everywhere. In other words, the green molecules are not always in the right place.”

A survey among Swedish transport buyers shows that awareness of mass balance is relatively widespread, but that actual use is still limited.

“Companies are hesitant, partly because there are no green molecules in the tank and therefore a fear of being associated with greenwashing. They want to be completely sure that it leads to real emission reductions. There is concern that the solution will not hold up under scrutiny, that it will be reviewed and that shortcomings will be discovered. There are examples of companies that have purchased mass balance services but chosen not to use them in their marketing,” says Desirée Grahn.

The issue of mass balance solutions has become more prominent because the Greenhouse Gas Protocol, which sets the framework for the Science Based Targets initiative, is expected to issue guidelines on how mass balance may be used.

“There is a risk that it will not be permitted, which could create challenges in many parts of the biogas value chain. From the Greenhouse Gas Protocol’s perspective, there are concerns that mass balance solutions do not result in increased use of biogas – that they do not lead to what is referred to as additionality.”

The pre-study – which clarifies and explains many of the complex concepts surrounding mass balance solutions – shows that both producers and users of biogas see it as problematic if mass balance solutions were not allowed. This would mean higher costs and the need for new, separate infrastructure.

“Biogas is very local by nature, and each individual user within shipping needs a fairly large volume. To make this work, a mass balance mechanism is needed to enable access to biogas bunkering in ports. This may also involve bunkering between countries. Volumes bunkered in the Netherlands can be used on paper in Sweden. In short, the issue is really about the fact that the green molecules are not always in the right place.”

In summary, the results of the pre-study show that mass balance principles have great potential to contribute to the climate transition of shipping, but that “clearer regulations, increased transparency, and harmonization of certification systems are required to ensure effective and credible application. The combination of technical solutions, market initiatives, and policy instruments is shaping a new structure for sustainable shipping in which climate benefits can be allocated, reported, and verified even in complex fuel systems.”

The pre-study Voluntary Climate Targets and Their Impact on the Use of LBG in Shipping was authored by Desirée Grahn, Elin Malmgren, Anders Hjort, and Linda Styhre (all at IVL Swedish Environmental Research Institute), and Björn Samuelsson (Uppsala University).