How does EfW work?
In the most widely used EfW process, waste is burned on a moving grate. Air is introduced above and beneath the grate in carefully controlled amounts to ensure proper combustion. Good combustion means fewer emissions. The hot gases released are directed to a boiler to recover the heat. Around 600 kilowatt-hours of electricity per tonne of waste burned can be recovered. The combustion gases are then cleaned in several stages to a strict standard set by the Waste Incineration Directive (WID), which are monitored by the Scottish Environmental Protection Agency in Scotland (SEPA) and the Environment Agency (EA) in England, Wales and Northern Ireland. Around 75 per cent of the waste input in to the EfW facility will be re-used as either energy or residual material. In future, this figure could rise to as much as 97 per cent depending on the development of future facilities.
