Decarbonisation of residual waste infrastructure: Scottish Government response

2. Summary of main findings and recommendations

11. The Second Report sets out nine new recommendations and confirms two provisional recommendations made in the First Report. It reiterates that the best approach to decarbonising residual waste treatment is avoiding residual waste in the first place, through waste reduction and source segregated recycling. However, for unavoidable residual waste, the most feasible options appear to be:

• advanced sorting (also called pre-treatment) to remove recyclable material from residual waste ahead of incineration;
• using heat, for example through connection to heat networks; and
• deployment of carbon capture use or storage (CCUS).

12. The Report suggests that, while the source segregated collection of materials is preferable, it would be beneficial to remove additional recyclable material, particularly plastics, from residual waste through advanced sorting. Moreover, the report notes that advanced sorting would be a quicker and more reliable route to decarbonising the waste sector than heat networks and CCUS. As such, the review makes three recommendations (Recommendations 13, 17 & 19), to tighten requirements for pre-treatment (confirmed from previous report) and to stop plastics from being incinerated by 2030 through policies to reduce plastic production and use, promote source segregation of all plastic wastes, and implement advanced sorting of residual waste.

13. However, the Report is also conscious of the difficulties in increasing the pre-treatment of waste and recommends that when implementing policies described above, the Scottish Government ensures there is no increase, and ideally a decrease, in the amount of plastics exported (recommendation 18).

14. The review notes that any policy measure that places a cost on emitting GHGs could be used to promote the various approaches to decarbonising residual waste management infrastructure set out above. It, therefore, recommends that the Scottish Government supports the inclusion of incineration in the UK Emissions Trading Scheme (Recommendation 16).

15. The review notes that heat networks offer only a partial solution for decarbonisation as many incinerators will struggle to connect to heat users. However, heat networks do have a wider role to play in decarbonisation, whatever energy source is used, so their connection to incineration plants is beneficial. Therefore, the Report confirms the First Report's provisional position that heat networks should be pursued where possible but not seen as a reason to build an incinerator (Recommendation 14).

16. The review also notes that capturing carbon dioxide emissions from incineration – both fossil and biogenic – is an apparently attractive solution and earlier deployment will result in greater benefits. The review, therefore, recommends that where incinerators already have planning permission, decision-making prioritises the facilities where CCUS is most feasible (recommendation 20). In addition, the review recommends that the Scottish Government consider support for emerging Carbon Capture and Utilisation (CCU) technologies that could overcome current challenges to deployment for facilities already in operation (Recommendation 21).

17. In considering the modelling commissioned for the review, the review noted that how emissions from incineration are typically reported does not necessarily provide a systemic view of the resource and waste management sector. The review, therefore, recommends that the Scottish Government consider how biogenic carbon is included in future resource and waste management sector modelling and how this influences decision-making (Recommendation 15).

18. The Report also commented on landfill gas capture. It recommended that the Scottish Government ensures maximum capture of landfill gas for open and closed landfill sites and develop new approaches to do this as methane levels decrease (Recommendation 22). It also recommends that the Scottish Government consult with landfill owners and operators to address the consequences of the withdrawal (in 2037) of current financial incentives for landfill gas management (Recommendation 23), which may impact how much gas is collected and used.