Operator of incinerator pledges emissions will be well below legal limit
Published 22/08/2016 | 02:30
The Poolbeg Incinerator, or Dublin Waste to Energy Plant, is enormous. The size of three football pitches, at 52 metres, it is also higher than the Aviva Stadium.
But it is designed to be aesthetically pleasing. The architects claim that it resembles a conch, or shell of a sea snail, although beauty is in the eye of the beholder.
John Daly, general manager of the €500m plant, said the reason the 600,000-tonne capacity facility looked out of place on the heavily industrialised Poolbeg peninsula was because it is "too nice".
He explained: "The curves added 15pc to costs, because they are very difficult to do. If the building looks out of place, is because it's too nice, being beside a scrap-metal facility, power plants and waste-water treatment plant."
It was the subject of bitter local opposition, a protracted planning inquiry, complaints to the EU and Competition Authority and controversy over the €100m-plus spend on land acquisition and consultants by the city council. But the first waste will be treated in the first quarter of next year.
Almost 520,000 litres of diesel will be needed to bring the two lines into operation. After that, the waste provides the fuel.
But Mr Daly insisted that despite local fears, Ringsend and Sandymount would not be inundated with trucks.
Most of the waste, up to 90pc, will be shipped through the Dublin Port Tunnel and fewer trucks are expected to appear on the streets than are allowed under the planning permission.
All the waste treated would previously have been directed to landfill and nothing hazardous is allowed.
"There will be less vehicles when we're operational than there are (on site) today," Mr Daly said.
Trucks carrying waste will drive into the plant and all work will take place inside the building under negative air pressure, which reduces odours.
The waste is to be fed by crane into a feed hopper and pushed by ram onto moving grates. It is burnt at temperatures of at least 850C and the heat produced transforms water in boiler wall tubes into superheated steam. This steam drives turbines to generate electricity for use in the plant and export to the grid.
Enough power for 80,000 homes will be produced, along with heating for a further 50,000.
Dublin City Council is responsible for the infrastructure needed for the district heating system and it will share a portion of all revenues generated.
Around 120,000 tonnes of ash will be produced, most of which will be used for road building or as cover in landfill.
Some 25,000 tonnes of fly ash, a hazardous material, will have to be exported for treatment in a specialist facility at a cost running into "several million" euro a year.
But there is understandable concern about emissions, Mr Daly admitted. He insisted that the combustion gas produced during the burning process - including the start-up phases - would pass through a three-stage air-pollution control (APC) system and the plant will operate well below legal limits.
Mr Daly said that around 40pc of the construction costs were for the air-pollution and control systems, provided by a Swiss company, Hitachi Zosen Inova (HZI).
The Environmental Protection Agency (EPA) will have full access to the APC system and real-time information will be available on the internet.
Covanta has "no problem" with any breaches or concerns around emissions notified or raised with the EPA being published.