Resource Use

Defra updates energy-from-waste guide

The Department for Environment, Food & Rural Affairs (Defra) has outlined the ‘future policy direction for energy from waste’ in a new version of its ‘Energy from waste: A guide to the debate’ document.

First published in February 2013, the document aims to ‘provide a starting point for discussions about the role energy might have in managing waste’. It contains various chapters on different aspects of energy-from-waste (EfW) technology, ranging from outlining the purposes and functions of EfW facilities to discussing how an EfW strategy might be implemented.

It is intended to help ensure that EfW ‘and its place in the waste hierarchy’ is ‘understood and valued’ by all households, businesses and the public sector in the same way as reuse and recycling.

In the new version, which does not set out any new policy, Defra outlines its ‘future policy direction’ for the energy technology, outlining a range of considerations that should be taken before building or investing in a new EfW plant.

Limiting biogenic material in EfW

Defra outlines that although EfW is ‘generally seen as recovery’, it can also be classed as recycling or disposal. For example, it states that anaerobic digestion (AD) of source-segregated waste ‘while technically recovery, can in certain circumstances count towards recycling targets and actually be better environmentally’, while waste incineration where energy is either not recovered or done so ‘inefficiently’ is classed as disposal.

It adds that ‘ideally we should be minimising the fossil content of waste going to energy recovery’, which could be done by ‘seeking necessary streams from landfill or supporting recycling of other components that redress the balance e.g. removing a greater proportion of fossil plastics to make up for a loss of biogenic material’.

Further, unless it can be ‘clearly demonstrated there is an overall environmental benefit in doing so’, biogenic material that might otherwise have been separated and ‘more beneficially processed in a different way (e.g. through AD)’ should not be left in or added to refuse-derived fuel. (Defra says it will be issuing a call for evidence later this year to investigate the extent to which there is an environmental case for intervention in RDF markets, including exports.)

Considerations for new plants

To help potential investors understand ‘government’s vision for the future’ for EfW, Defra outlines that new and future plants will need to be based on technology that ‘at least constitutes recovery, not disposal’.

The document suggests that the four ‘key principles’ that underpin current thinking on EfW and ‘which are expected to remain critical to the development of a sustainable policy into the future’ are:

  • EfW must support the management of waste in line with the waste hierarchy;
  • EfW should seek to ‘reduce or mitigate’ the environmental impacts of waste management and then ‘seek to maximise the benefits of energy generation’;
  • Government support for EfW should provide ‘value for money’ and make a ‘cost effective contribution to UK environmental objectives’ (in the context of overall waste management and energy goals); and
  • Government will remain ‘technology neutral’ except where there is a ‘clear market failure’ preventing a technology from competing on a level footing.

Further to this, Defra highlights that key considerations for both new and existing plants going forwards will be:

  • maximising the efficiency of existing plants to ‘delay reaching, and avoid going beyond, any balance point’ (in which EfW could perform worse than landfill in carbon terms);
  • limiting the lifetime of an electricity-only EfW plant;
  • developing energy outputs ‘beyond electricity’ (such as through heat), both for new plants and through ensuring that existing plants that are combined heat and power (CHP) ‘ready’ become ‘CHP in use’; and
  • avoiding the use of waste in energy recovery with ‘insufficient biogenic content to deliver environmental benefits, or capturing the environmental cost of doing so’.

EfW vs recycling

Touching on the debate of EfW ‘overcapacity’ and its impacts on recycling (and apparently landing on the side of increasing incinerator capacity), the document states that ‘increased prevention, reuse and recycling, does not necessarily mean less waste feedstock for energy recovery’ as there is a ‘large amount of potentially combustible residual waste still going to landfill that could be utilised in energy recovery’.

As such, the government considers ‘there is potential room for growth in both recycling and energy recovery – at the expense of landfill’.

The document reads: ‘This consideration is particularly pertinent at the local level where the presence or plan for an energy-from-waste facility is often perceived as a potential brake on initiatives to optimise local recycling.

‘However, local waste successfully diverted to more beneficial processing higher up the hierarchy can be replaced by participation in the wider waste market through further diversion of other sources from landfill. Thus the need to “feed the beast” to maintain economic energy from waste operation should not impede continuing improvements in prevention, reuse and recycling of the host community.’

The document adds that ‘if material is so contaminated that the resources required to clean and process it for recycling would outweigh the benefits of recycling, then it may be better going to recovery’.

However, if there is a ‘cost effective, practical route for ensuring that material can be collected in a less contaminated state so that recycling is viable, the presence of a planned or operational energy from waste alternative should not impede doing so’.

The chapter concludes: ‘The sector will need to ensure more waste is pulled out of landfill or new sectors such as commercial and industrial waste are better exploited to maintain feedstocks. With diminished or changing feedstock energy from waste must evolve both to deliver its potential as a partially renewable energy source and as demonstrated by recent modelling, to maintain its environmental benefits over landfill. This will require much wider utilisation of heat or other higher energy outputs both for new and existing plants.’

Alongside the updated EfW guide, Defra has also published updated waste technology briefs that provide more details relating to specific energy from waste technologies, such as mechanical biological treatment (MBT) and incineration of municipal solid waste.

The guidance has been welcomed by several members of the waste and resources industry, with Matthew Hindle, Policy Manager at the Anaerobic Digestion and Biogas Association (ADBA) telling Resource: “Anaerobic digestion is about more than just energy recovery: recycling critical nutrients like phosphorus is essential to future food production. The explicit statement in the energy from waste guide that Lifecycle Carbon Analysis shows AD is ‘better than other recycling and recovery options’ should help local authorities and businesses who are looking at the waste hierarchy and making decisions about food waste treatment.

“It is also right to highlight that food waste is not particularly suitable for traditional energy from waste plants, due to the high water content and the importance of nutrient recycling.

“Given the difficulty of creating standards for mixed waste – which the guide also recognises – the government should prioritise source segregation for food waste which will help the UK maximise the economic and environmental potential of anaerobic digestion.”

Read the updated ‘Energy from waste: A guide to the debate’ document.