Passenger trains are being powered by vegetable oil for the first time in the UK, an operator said.
Chiltern Railways began using hydrotreated vegetable oil (HVO) to fuel part of its fleet on Thursday to reduce its impact on the environment.
HVO is made almost entirely from used cooking oils and can reduce greenhouse gas emissions by up to 90% and air particulates by 85% compared with conventional diesel fuel.
Chiltern Railways is using HVO to power its Class 68 locomotives as part of efforts to decarbonise its operations.
The fuel is more expensive than traditional diesel.
Richard Allan, managing director for Chiltern Railways, said: “We are determined to operate a railway that is easier, greener and better for our customers.
“The conversion of a key part of our fleet of trains to HVO fuel will make a big difference in terms of emissions.
“We have listened to customers and stakeholders who rightly highlighted air quality as a key concern to us, and have taken action to minimise the impact on the environment that these trains have through cleaner, greener fuel.
“This is a strong step in the right direction, and we want to do more.
“In the next few days, we will be inviting train manufacturers for proposals for new trains to replace our oldest diesel trains.”
Rail minister Huw Merriman said: “Trains are already one of the greenest ways to travel, and we want to build on this further by creating a rail industry that helps us achieve our ambitious net zero targets and delivers even more benefits for passengers.
“A reduction in greenhouse gas emissions by up to 90% is an incredible achievement that gets us one step closer to realising these, and I commend Chiltern on pioneering this fuel.”
The Government has a target of phasing out diesel-only trains by 2040.