The biodiesel is made at the Argent Energy plant in Motherwell
Residents and schoolchildren in a Norfolk town are taking part in a trial of a "green" oil that can be used in boilers to heat homes.
The town of Reepham is taking part in the 12-month scheme to use fuel made from used vegetable oil and animal fat for heating and hot water.
Researchers from the University of East Anglia (UEA) are leading the trial.
They say if it succeeds it could reduce the carbon footprint of almost two million homes in the UK and Ireland.
The local primary and secondary schools are among 30 properties involved in the project.
The fuel being used is a biodiesel manufactured by Argent Energy, in Scotland, from used vegetable oil and tallow, which is blended with conventional oil by Pace Fuelcare, in King's Lynn, Norfolk, before the company delivers it to the properties.
The blends have a similar or lower carbon footprint than natural gas.
The UEA says the aim of the project is to prove that renewable heating oil is a viable option.
The children are enthusiastic about cutting carbon emissions - and we have energy monitors for each class
Reepham Primary School
Project manager Dr Bruce Tofield, from the UEA, said: "This is a major initiative in developing lower carbon heating options for millions of properties, especially in rural areas, which depend on oil-fired heating."
Lisa Cook, head teacher at Reepham Primary School, said: "The children are enthusiastic about cutting carbon emissions and we have energy monitors for each class.
"They are genuinely thrilled to be taking part in such a significant experiment."
Jeremy Hawksley, director general of the Oil Firing Technical Association (Oftec), one of two bodies that represent the industry in the UK, said results from the trial were extremely encouraging so far.
He said: "Having a liquid biofuel that is interchangeable with domestic heating oil means that around 1.9 millions households in the UK and Ireland will be able to use renewable technology to heat their homes, with very few modifications to their existing heating systems."