"The significant environmental benefits of small-scale EfW with heat recovery are likely, in any qualitative/quantitative assessment, to outweigh the additional cost when compared to large scale EfW"
Highlands Council
Inverness, Scotland: The Highland Council decided yesterday on a small scale energy from waste plant (Efw) to serve the Island of Skye, and Lochalsh in the Western Zone of the council’s area.
What is more, the council deserves credit for taking the decision on environmental grounds rather than cost, following detailed environmental assessment of the options available.
The council says that the decision is in accordance with its commitment to meet landfill allowance targets to divert biodegradable municipal waste (BMW) from landfill.
The decision was taken following a review of the council’s waste management strategy to reflect the closure of a landfill site at Portree in March 2007, that had originally been expected to stay open until at least 2020.
The effect has been that waste from the Western Zone of the huge area of highlands and islands covered by the council, has to be transported some distance to a landfill in the Central Belt of Scotland.
Small scale Efw plant near Grimsby
Environmental assessment
This is clearly not the best practicable environmental option (BPEO) for the area and council officers, assisted by the Scottish Environmental Protection Agency (SEPA), reviewed the situation based on five options:
- Landfill disposal outside of Skye and Lochalsh
- Mechanical/biological treatment (MBT) with residues disposed to landfill
- Energy from Waste (EfW) at a large facility in the Inner Moray Firth
- EfW at a small-scale facility located in Lochaber treating waste from throughout the West Zone
- EfW at a small-scale facility located within Skye and Lochalsh treating waste from Skye and Lochalsh only.
The council says that SEPA worked on a life-cycle assessment (LCA) for the five alternatives which resulted in the two small scale Efw plants outperforming the rest from an environmental perspective because of the ease with which they can be linked to district heating schemes.
A Skye and Lochalsh facility was marginally favoured on mileage grounds in the SEPA analysis, according to the Highlands Council.
The preferred option, agreed by the Transport, Environment, and Community Services Committee on Thursday, was a small scale Energy from Waste Plant with heat recovery identified as the preferred treatment method for residual wastes from Skye and Lochalsh.
The Committee also agreed to undertake further work including the preparation of a detailed comparative cost assessment, identification of possible development sites and consultation with potential end users for the heat produced by such a plant.
Costs comparisons
Initial work on costs undertake by the council indicated that large-scale EfW is likely to be the cheapest option beyond 2010.
The small-scale plant in Lochaber is likely to be next cheapest, followed by the small-scale plant based within Skye and Lochalsh.
The council considers that the cost differences between the three EfW options is likely to be moderate.
MBT came out of the exercise as the most expensive option, and the only one which is likely to be more expensive than landfill beyond 2010.
However Highlands Council says: “The significant environmental benefits of small-scale EfW with heat recovery are likely, in any qualitative/quantitative assessment, to outweigh the additional cost when compared to large scale EfW. Accordingly, small-scale EfW with heat recovery appears to be the clear BPEO for residual waste treatment for Skye and Lochalsh. The location of such plant will be dependent on finding suitable end-users for the heat, such as a district heating scheme”.