August 10th marks International Biodiesel Day, a date that commemorates the first engine Rudolf Diesel started in 1893 using palm oil. More than a century later, this renewable fuel is emerging as one of the most viable alternatives for decarbonizing transportation and reducing dependence on fossil fuels. In Spain, biodiesel production is progressing slowly, but there are concrete examples demonstrating its viability, such as the Greenfuel Extremadura plant in Los Santos de Maimona and used oil collection initiatives in provinces like Albacete.
The commemoration not only seeks to celebrate achievements but also to highlight the remaining challenges. While in countries like Brazil and Paraguay the mandatory biodiesel blend in diesel fuel for land vehicles already exceeds 15% and 7% respectively, in Spain the sector continues to struggle to gain a foothold. The president of the Extremadura Energy Cluster, Vicente Sánchez, summarizes it clearly: “Introducing biodiesel is proving difficult because it requires large plants, and the sector is currently more focused on electrification.” However, the environmental and economic advantages are hard to ignore.
A fuel with clear advantages for the environment and the economy
Biodiesel is obtained from vegetable oils, animal fats, or recycled cooking oils through a chemical process known as transesterification. Its main advantage lies in its ability to reduce CO₂ and particulate emissions compared to traditional diesel, in addition to being biodegradable and providing better engine lubrication. In terms of a circular economy, its production allows for a second life for waste that would otherwise end up in landfills or the sewage system.
The data supports this view. According to the Albacete Provincial Environmental Consortium, each resident generates an average of four liters of used cooking oil per year, which amounts to nearly 700.000 liters annually across the province. In 2025, 48.961 kilograms of this waste were collected, preventing a significant portion from ending up in the natural environment. As experts warn, a single liter of oil can contaminate up to 1.000 liters of water , in addition to clogging pipes and increasing the cost of wastewater treatment plant maintenance.
The Greenfuel Extremadura plant, located in Los Santos de Maimona, is an example of how this fuel can generate employment and local wealth. The facility uses used cooking and vegetable oils to produce advanced second-generation biofuels, and its capacity is scalable, meaning it will be expanded according to market needs. Vicente Sánchez emphasizes that this factory is having an increasing impact on employment in the area, and that the Extremadura region is playing a growing role in research thanks to CICYTEX, which has been working for years on biodiesel, biogas, and biomass projects.
The challenge of energy independence and institutional support
One of the most frequently cited arguments by biodiesel proponents is its ability to reduce Spain and Europe's energy dependence in the face of geopolitical tensions, such as the wars in Ukraine and Iran. Because it is produced from renewable and locally sourced raw materials, this fuel avoids being subject to the fluctuations of international oil markets. However, the sector laments that government bodies are not investing more decisively in this technology.
The Extremadura Energy Cluster is urging both the central government and the regional government to take further steps regarding the Self-Consumption Law and improve access to the electricity grid to enable scaling up production. They are also calling for greater public awareness of the importance of recycling used cooking oil, a simple process that, as the Albacete Provincial Council points out, is free and available in numerous municipalities. The process is straightforward: let the oil cool, store it in a plastic bottle, and deposit it in the designated containers.
Comparisons with other countries in the region are inevitable. Brazil already requires a mandatory 15% biodiesel blend in its diesel fuel, while Paraguay has temporarily set 7% with plans to increase it to 8% by 2027. In Argentina, installed capacity exceeds 3,2 million tons per year, although the biodiesel industry is facing a crisis due to various limitations. In Europe, maritime transport has become a new battleground: Brazil's National Petroleum Agency has already approved a public consultation to allow the use of pure biodiesel (B100) in shipping, a trend that could soon reach the Old Continent.
Finally, it's worth remembering that International Biodiesel Day is not only a time to celebrate progress, but also to reflect on the challenges. Responsible production, the use of waste as raw material, and the need for stable regulatory frameworks are key for this renewable fuel to become a viable option. In Spain, there is still a long way to go, but the examples of Extremadura and Albacete demonstrate that the raw material exists, the technology is proven, and the environmental benefit is undeniable . What is lacking is political will and a firm commitment to a cleaner and more self-sufficient energy model.
