As climate urgency grows and emissions targets become more stringent, biofuels are taking on a starring role in the transition to sustainable energy. Their flexibility, drop-in potential, and circular sourcing make them a critical piece of the puzzle.
But one of the most emissions-intensive (and difficult to decarbonize) sectors has now firmly set its sights on biofuels: the maritime industry.
The shipping sector accounts for roughly 3% of global greenhouse gas emissions according to the International Maritime Organization (IMO). And as pressure mounts for the industry to align with global decarbonization goals, biofuels offer one of the most practical and immediate paths forward. Enter: bio-bunkering—a rising trend that is reshaping the marine biofuel market.
Bio-bunkering refers to the practice of supplying ships with bio-based fuels, either as pure biofuels or as part of a blended fuel mixture, to power their engines. In simple terms, it’s bunkering (refueling a vessel) with marine biofuel instead of conventional fossil-derived marine fuels like heavy fuel oil (HFO) or marine gas oil (MGO).
But what is biofuel, exactly? Biofuels are fuels produced from renewable, biological sources—such as used cooking oil, animal fats, or plant-based feedstocks. In the marine sector, these fuels are often refined into biodiesel, renewable diesel, or even more advanced drop-in fuels that can replace fossil fuels without modifying ship engines.
Why does this matter? Because bio-bunkering allows shipping operators to substantially lower lifecycle emissions without waiting for large-scale infrastructure changes or propulsion technology overhauls.
The list of bio-bunkering hubs is growing fast, fueled by regulatory pressure, industry commitments, and technological readiness. Early adopters include:
As engine compatibility improves and logistics become more streamlined, marine biofuel suppliers are expanding into new regions. This, in turn, creates more opportunities for fleets to bunker with sustainable fuels.
Several types of biofuels are now making their way into the marine biofuel supply chain. What is an example of biofuel used in ships today? Here are a few:
The fuels vary in availability, cost, and emissions performance. However, they all aim to reduce the carbon intensity of marine transport.
Switching to bio-bunkering or even partial blending offers a number of clear benefits:
In short, it’s a practical decarbonization solution that aligns environmental responsibility with operational efficiency.
Of course, bio-bunkering isn’t without its challenges. Some of the most common concerns include:
These points are often raised when people ask, “What is the downside of biodiesel?” or “What are the risks of biodiesel?” And these concerns are especially valid in critical, long-haul maritime operations. Fortunately, advancements in fuel testing, certification, and blending guidelines are addressing these concerns head-on.
As the marine industry confronts rising emissions pressure, bio-bunkering stands out as one of the most immediately actionable solutions. It bridges the gap between today’s fossil-heavy systems and tomorrow’s zero-carbon aspirations.
Whether used as a transitional fuel or long-term option, marine biofuel is proving that low-emissions shipping is more than just a goal. It’s a course we’re already navigating.
Bio-bunkering won’t solve all marine-based sustainability challenges alone. But as regulators tighten the screws and shipping giants set carbon targets, the case for integrating sustainable marine biofuel becomes even more essential.