The ban on the landfilling of biodegradable municipal waste in Scotland, which was originally proposed for January 2021 and then extended to 2025, has resulted in the development and operation of six Energy from Waste plants (EfW) across Scotland.
Energy from Waste (EfW) plants in Scotland
These facilities actively use municipal and general waste as fuel to generate heat and power, with another five EfW plants are currently in planning or under construction in Aberdeen, Falkirk, Dundee, Westfield and Drumgray.
How do Energy from Waste plants work?
EfW facilities produce electrical power, most of which is fed into the national grid to provide a consistent base load of renewable electricity and renewable heat, which is used more locally. EfW facilities also produce Incinerator Bottom Ash (IBA) that is rich in aggregates.
When IBA is rigorously processed to remove metals, it can be used as a replacement for virgin aggregate as ground-fill and sub base under a low permeability surface.
The introduction of the IBA processing technology in Scotland presents a real opportunity to utilise a low carbon option in ground works. It also promotes a Circular Economy (CE) for the residual waste produced from the built environment once the process of waste management segregation has taken place.
The built environment industry has done incredibly well to segregate and recycle 90% of construction materials, and is now working hard towards reuse where possible.
However, with some clients' contracts imposing a 'Zero to Landfill' policy on builds and a 'no general waste' provision on site, there will still be small amounts of residual waste finding its way into skips, often as contamination. This type of waste will generally end up in the EfW process. General waste collection on construction should, however, be considered acceptable. Reducing contamination in other segregated waste, such as timber, inert and plasterboard skips, with the general waste becoming feedstock for renewable energy and the by-product becoming low carbon aggregate.
Furthermore, the use of IBA Aggregates on site can provide a genuine reduction in carbon, rather than a token carbon offset. IBA Aggregates can offer construction companies tendering for 'Zero to Landfill' projects the opportunity to not only prove this to clients, but to further offer a route back into ground works of future projects, demonstrating a CE approach.
The use of aggregates from the IBA source has a number of important sustainability benefits for construction and will shortly be available all over Scotland as a workable alternative to quarried aggregates.
Having joined Construction Waste Portal in October 2022, Levenseat are confident that they can play their part in a low carbon, sustainable future for the built environment through innovative methods and extensive industry experience.
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