A massive biogas plant planned in a closed Keynsham quarry has been unanimously rejected amid claims it would create traffic chaos, lighting pollution, dangerous spores and smells.

Hundreds opposed Resourceful Energy Anaerobic Ltd (REAL)'s bid to build an anaerobic digester plant capable of processing 92,000 tonnes of food waste and crops a year – nearly four times the size of a facility approved in 2014 that was not built in line with the planning permission – to generate up to 2.2megawatts of energy.

Refusing permission, planning chiefs said the development was not needed and would not benefit the residents of Bath and North East Somerset.

Representing campaign group Protect Our Keynsham Environment, Rob Duff said the development was a "very different beast" to the scheme approved in 2014 and there was "absolutely no need" for it.

"I have been a town planner for over 30 years and have never come across unauthorised or proposed development as harmful to the green belt as that before you today.

"The site is simply unsuitable for the proposed development. Even if a need did exist, this is not the right site for it."

REAL said in its application more than 6,000 tonnes of CO2 would be saved every year but planning officers said it had omitted the 81,000 tonnes of CO2 that would be emitted during the plant's construction that would take 24 years to offset.

They said the 2.2 megawatt capacity would contribute two per cent to the council's renewable energy target, which is currently facing a significant shortfall, but found the proposal "will not save more emissions from renewable energy generation than it creates from its annual operation alone".

Defending the project, REAL director Phil Gerrard said the officer assessment contained significant inaccuracies, adding: "Members should consider how far off course the district is from its obligations on renewable energy and give significant weight to the contribution this project makes to [the council's] renewable targets and our overall energy security."

In a written statement to the meeting, Councillor Lisa O'Brien said: "We must be careful we don't play into the hands of self-interested parties who seek to manipulate our impetus [to tackle the climate emergency] for their own financial gain.

"We have to tackle the climate emergency, but not at any price. The physical wellbeing of our residents and our local environment must come first."

REAL's plans propose using up to 25,000 of food waste, with the rest made up of purpose-grown crops such as maize.

Councillor Alastair Singleton said producing the required amount of maize would require up to 650 hectares of fertile farmland that could be used to produce food, a move he described as "bonkers".

"This is not a green or environmentally sound project. It's a damaging commercial enterprise, masquerading in diaphanous green clothing."

The district's food waste is already sent to an anaerobic digester in Avonmouth to generate electricity. Cllr Eleanor Jackson said: "We sympathise with the people at Avonmouth who have to put up with terrible smells and disruption and heavy vehicles but we don't want our share of it here in Bath and North East Somerset. It may be nimbyism but this is beautiful green belt and it should be kept for the residents to enjoy."

Councillor Paul May added: "The renewable energy case has not been made and will do nothing for Bath and North East Somerset's communities except create traffic chaos, lighting pollution, dangerous spores and smells."

Councillor Alan Hale said safety issues alone were enough to reject a scheme that would send 28,000 HGVs a year onto inappropriate roads, risking fatal collisions.