A common sight in the British countryside, bracken -- a type of fern -- is now being hailed as the next big source of biofuel.
Based in the south west of England, Brackenburn produces "brackettes" – biomass pellets made from bracken that they shred and compress into briquettes which produce much more heat when burnt than oak.
"In our estimation there's 2.5 million acres of bracken in the UK… it's a huge area," Barry Smith, Brackenburn's marketing and sales director, told CNBC in a phone interview.
"Left unchecked, bracken encroaches by three percent a year… at the end of the day there's no use for it whatsoever," Smith added. "It's a nuisance and to call it a crop is kind of giving it a status it doesn't deserve."
Brackenburn say that their product burns hotter and longer than oak. This, they say, is down to the fact that their Brackettes have a bigger calorific value and lower moisture content.
"Once it's cut, once it's dried, once it's briquetted, the calorific value is greater than the equivalent briquette would be of oak," Smith said.
Currently, the briquettes are harvested, manufactured and sold locally – for around £6.99-7 for 10 kilos – which is helping to boost the economy, according to Smith.
"We're extending the harvest season by a couple of months, we're harvesting in November, December, I mean all these harvest machines, all this machinery is put to bed, so we're creating employment, or generating employment in rural areas.
Described by the Royal Horticultural Society (RHS) as "a tough plant to remove", bracken also contains carcinogens that the RHS says are linked with both stomach and oesophageal cancer.
Brackenburn say that when bracken dies, its carcinogens die too, and that they only harvest it when it is dead and brown.
Smith said that while the business was scalable to other parts of the country rich in bracken, the ethos was firmly local.
"We want to contain ourselves within 100 mile radius of where we get the raw material from and where we're selling it to," he said.