Marcus Gustafsson emphasized the importance of assessing fuels from a well-to-wheel perspective, rather than the narrower tank-to-wheel view.
"When we include the full chain—from production to usage—the climate impact of a fuel can look very different," he explained. "Electric vehicles are often seen as clean, but if the electricity comes from fossil sources, the overall emissions may still be high."
By using life-cycle assessment (LCA), Marcus Gustafsson showed that biogas, especially when upgraded to biomethane and produced sustainably, can offer significant reductions in greenhouse gas emissions—sometimes even outperforming electric alternatives.
System expansion boosts biogas benefits
One of the most powerful tools in evaluating fuel sustainability, according to Marcus Gustafsson, is system expansion. This means including side-benefits in the analysis, such as using digestate—a by-product of biogas production—as a biofertilizer.
"This can replace fossil-based fertilizers and further reduce environmental impact," said Marcus Gustafsson. "When we account for these added values, the climate performance of biogas improves dramatically."
He presented data showing that vehicle gas in Sweden, where biomethane makes up the majority of the supply, has much lower climate impact than fossil diesel. Even in countries like France, where the share of biomethane is lower, vehicle gas still outperforms fossil fuels.
Carbon Dioxide: From emission to resource
Another focus of the presentation was the role of carbon dioxide captured during the biogas upgrading process. Today, it’s used in beverage carbonation, fire extinguishers, and wastewater treatment—but its potential is far greater, Marcus Gustafsson argued.
"Rather than just storing COā underground, we can use it to make synthetic fuels or as part of sustainable industrial processes," he said. "That turns a waste product into a resource."
While technologies like carbon capture and storage (CCS) are gaining popularity, Marcus Gustafsson cautioned that storing COā often requires large energy inputs and may shift environmental burdens elsewhere. Using COā effectively, he said, is a more integrated and potentially beneficial approach.
A strong case for biogas
Summing up his presentation, Marcus Gustafsson stated that biogas can—and should—be considered a serious contender in the race for sustainable fuels.
"Biogas offers low climate impact, reduced air pollution, and additional environmental benefits—especially when we take a systems perspective," he said. "In many cases, it performs as well as, or even better than, renewable electricity."