The race to decarbonize sectors that cannot be powered by batteries has placed biofuels at the center of the debate. In aviation, mining, and heavy transport, renewable fuels appear as a readily available solution, without the need to completely overhaul engines and infrastructure. This practical advantage coexists with a fundamental problem: regulatory demand is growing faster than the supply of raw materials.
In Spain and the rest of Europe, EU regulations are driving the replacement of some kerosene, diesel, and fossil fuels with alternatives such as SAF, HVO, and biomethane. The goal is to reduce emissions in activities that are difficult to electrify, but the path is not without its challenges: traceability, costs, waste availability, and competition with traditional fuels are determining the actual pace of the transition.
An immediate solution for sectors without electricity.
Sustainable aviation fuels (SAFs) have become the most mature tool for beginning to reduce emissions in air transport. They can be blended with conventional kerosene and used in existing aircraft, provided they meet certification requirements, allowing progress to be made without replacing the fleet or overhauling the refueling system . The European Union has set minimum percentages through ReFuelEU Aviation for airlines and suppliers to incorporate these blends.
The same argument applies to other sectors where electrification has yet to take hold: heavy-duty trucks, mining machinery, biofuels in boats , ships, and intercity buses. HVO, produced from waste and fats, can be used in existing diesel engines and significantly reduce emissions throughout their life cycle. In Spain, Moeve and Emerita Resources have signed an agreement to use 100% renewable diesel in the Huelva mining project , an initiative that aims to demonstrate that heavy industry can reduce its environmental footprint without waiting for future technologies.
The fine print: waste, used oils and external dependence
The Achilles' heel of many biofuels lies in their feedstock. Agricultural waste, animal fats, and used cooking oils have clear limitations. Even if all of Spain's used cooking oil were collected, it wouldn't be enough to cover a significant portion of the kerosene the country consumes. Therefore, a substantial part of the raw material for producing SAF (smooth fuel oil) in Spain comes from China, Singapore, or the Netherlands , which adds to transportation emissions and undermines the idea of European self-sufficiency.
European regulations aim to prioritize waste and byproducts over first-generation crops, which are associated with food safety risks and competition for land use. However, available waste remains expensive and limited. In Germany, for example, stricter greenhouse gas emissions regulations have increased demand for biodiesel, bioethanol, and biomethane, but have also revealed that the supply of waste feedstocks cannot keep pace.
Germany and NETWORK III are setting the pace
The RED III directive and German regulatory changes have altered the landscape. The German greenhouse gas quota for transport fuels rose from 10,6% to 12% in 2026 and is projected to reach 17,5% in 2027, in addition to increasing the percentage of advanced biofuels. These measures have boosted divisions such as bioethanol and biomethane, which, in Verbio's case, improved their operating results. Bioethanol and biomethane partially offset the decline in biodiesel margins.
The German company also warns that residual raw material prices will remain structurally high because demand is outpacing supply. For the next fiscal year, it expects growth to come from increased biomethane volumes and its US plants, while biodiesel production declines. Uncertainty centers on accumulated surplus quotas that could return to the market and put downward pressure on prices.
The pulse of APS with kerosene
In aviation, certified SAFs are "drop-in": they are mixed with fossil fuel and run in existing engines. This compatibility explains why the EU and ICAO consider them the primary path to decarbonization. Even so, current certification standards prevent the complete replacement of kerosene, so even in the best-case scenario, fossil fuel will continue to be burned for years to come.
Electronic fuel storage (e-SAF) systems, manufactured using renewable hydrogen and captured CO₂, have characteristics very similar to conventional kerosene and could utilize existing infrastructure. The problem lies in their energy and economic costs: producing one ton currently costs about twelve times more than conventional kerosene, according to EASA. Furthermore, meeting the 2050 targets would require more than 108 TWh of renewable electricity and 48.000 billion liters of water per year in Spain —an enormous amount of resources.
Spain: industrial potential and pending tasks
Spain has significant industrial potential. It is estimated that it could reach up to 22 million tons of technical capacity by 2030, which would allow it to lead SAF production in Europe. In Huelva, Moeve, in partnership with Apical, is developing a second- and third-generation biofuels plant integrated into the largest complex in southern Europe, with a cumulative investment of €1.200 billion and a capacity of 500.000 tons of HVO and SAF per year. The stated objective is to reach 2,5 million tons per year by 2030.
Emerita's mining project in the Iberian Pyrite Belt aims to use renewable diesel in the construction and operation of the mine, as well as in the transport of concentrates. The company estimates that this will prevent approximately 2.600 tons of CO₂ emissions per year, an amount comparable to the absorption of 170.000 trees. The proximity of production, the mine, and the export port seeks to create an industrial value chain in the province of Huelva.
What's needed for them to take off?
Renewable energy experts point to three key areas. The first is diversifying raw materials: in addition to used cooking oil, it's advisable to promote microalgae, lignocellulosic waste, and other technologies. The second is planning e-SAFs (electronic fuel storage systems) where renewable electricity, water, and available CO₂ coincide. The third is incorporating demand into the equation with taxation that shifts the environmental cost of kerosene to the price of train tickets and prioritizes rail alternatives for short journeys. Without these changes, biofuels will be a necessary but insufficient solution.
There are also calls to strengthen traceability to prevent fraud and double counting, as well as to reform taxes such as the VAT on SAFs to reduce the price gap. Meanwhile, the market is showing disparate strategies: some companies are expanding their investments in bioenergy, while others, like BP, are considering divesting their biofuel businesses in Brazil to refocus on hydrocarbons. This divergence reflects uncertainty about long-term profitability and the regulatory framework.
The final picture is of a sector that already offers real solutions for airplanes, trucks, ships, and mines, but remains tied to the availability of waste, the price of electricity, and the design of regulations. Europe and Spain have taken firm steps with quotas, industrial projects, and pioneering agreements; the challenge now is to increase production capacity without compromising water resources, soil, or forests. Biofuels are not a magic bullet, but rather one more piece of a transition that will require many technologies simultaneously.
