Renfe and Repsol completed an initial operational trial using hydrotreated vegetable oil (HVO) to power the Costa Verde Express, according to Renfe. The test run, conducted on a Series 619 locomotive fully drained of conventional diesel and refueled at the El Berrón depot in Asturias with 1,000 liters of Repsol’s ‘Nexa’ renewable HVO-blended diesel, marks a significant step in cutting emissions on Spain’s non-electrified rail routes.
Operational Trial of HVO on Spain’s Costa Verde Express
The Series 619 locomotive hauled the Costa Verde Express—part of Renfe’s Luxury Trains portfolio operating a six-day, five-night itinerary between Santiago de Compostela and Bilbao—during the live passenger trial. According to Renfe, the test successfully confirmed the technical viability of HVO in live passenger operations. Following the trial, Renfe and Repsol signed a protocol to promote HVO as an alternative to fossil diesel across Spain’s remaining diesel-worked routes.
Broader Decarbonization Goals in Spanish Rail
While 94% of Renfe’s passenger demand in 2025 was met using carbon-neutral electric traction, approximately 6% of services on rural or remote lines still rely on diesel. The HVO trial directly supports Renfe’s 2024 Sustainability Master Plan, which includes targeted measures to reduce emissions on unwired sections of the national rail network.
Did You Know?
While the vast majority of Renfe’s passenger demand relies on electric traction, remote and rural lines account for the remaining 6% of services that historically required fossil diesel.
Global Shifts Toward Renewable Fuels
The push toward renewable fuels extends well beyond Spanish rail transport. In Vietnam, FatHopes Energy partnered with PetroVietnam Oil Corporation (PVOIL) to establish a nationwide used cooking oil (UCO) collection ecosystem, transforming waste into certified renewable feedstock for sustainable aviation fuel (SAF). Similarly, Speedy approved Syntech ASB B100 biofuel for its power generation fleet following trials showing performance comparable to conventional EN590 diesel.
In aviation, EcoCeres partnered with SF Group, China National Aviation Fuel Group (CNAF), and the Civil Aviation Administration of China (CASRI) to launch a customized SAF commercial fueling programme. Meanwhile, Air Canada and Airbus unveiled plans to create a jointly funded Sustainability Co-Investment Platform, committing up to €9.2 million to support the commercial-scale SAF industry in Canada.
Frequently Asked Questions
What fuel was used in the Renfe and Repsol trial?
The trial used 1,000 liters of Repsol’s ‘Nexa’ renewable HVO-blended diesel to power a Series 619 locomotive.
What route does the Costa Verde Express operate?
The Costa Verde Express runs a six-day, five-night itinerary between Santiago de Compostela and Bilbao.
Why are non-electrified routes targeted for HVO?
While most of Renfe’s passenger demand uses electric traction, about 6% of services on rural or remote lines rely on diesel, making HVO an alternative to cut emissions on unwired sections.
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