The UK has been exporting refuse-derived fuel (RDF) to Europe for some time. In 2012, the amount rose threefold from the previous year to 892,000 tonnes; 690,000 tonnes were sent to the Netherlands, 67,000 tonnes to Denmark and 53,000 tonnes to Germany.
All these countries have surplus capacity.
At face value, this increase might be taken to indicate a significant shortfall in energy-from-waste (EfW) capacity in the UK. But the way in which we regard and deal with our waste can change rapidly during the lifetime of a treatment plant, as a result of economic, legislative, societal or technological factors.
So there is significant risk in reading into the current RDF export figures the need to build more UK capacity.
Because of over-capacity in northern Europe, gate fees for imported RDF are low - according to some sources, less than half of those for UK landfills or EfW plants.
So market forces alone could still lead to the export of UK RDF, regardless of local capacity.
The Environment Agency is currently allowing the export of processed waste to the continent. Those who see a need for more incineration capacity in the UK would undoubtedly like this to stop, and there is an argument that the UK should gain the benefits from its own waste.
There will always be some residual waste needing disposal, for example residuals and contaminated material from MRFs. At least some of this is probably best burnt in appropriate facilities with heat and power recovery.
Progress on meeting the 2020 targets on recycling and landfill diversion has been good, but the rate of increase in recycling last year was the lowest for more than a decade. There is a danger that once an EfW plant is built, the long-term commitment to feed it will lead to a slowing down in improvements in recycling, as is said to have happened in Denmark.
The high initial cost of an EfW facility requires certainty in the waste supply. But councils are increasingly switching from long-term (20+ years) to short-term (five-year) contracts.
Waste generation rates have also reduced in recent years, perhaps as a result of the recession. But it is also likely that there has been a genuine decoupling of waste generation rates from economic growth.
In the future, there will be stronger resource efficiency and economic arguments to recover trace materials such as rare earths and phosphates from wastes, so technologies better able to do this than thermal EfW will be required.
The risks of not building more EfW capacity in the UK are that:
- The UK is unable to realise the energy benefits of the combustion of wastes for which this represents a suitable treatment or destruction option.
- It remains necessary to export RDF to Europe, with the associated energy and transport costs, although these may be offset when the energy embodied in the plant and differential thermal conversion efficiencies are taken into account.
Conversely, the risks of building more EfW capacity in the UK are that:
- UK plants might be unable to compete on price owing to an overcapacity in Europe.
- It might result in a slowing down of improvements in direct recycling rates.
- Waste generation rates might continue to fall.
- Pressure on resources might require a more materials-focused approach to the recovery of value from waste.
The argument requires hard data (for example, as provided by Defra’s New Technologies Demonstrator Programme) and a degree of foresight to call.
Geoff Watson, research fellow in engineering and the environment at the University of Southampton and and William Powrie, professor of geotechnical engineering and dean of the faculty of engineering and the environment at the University of Southampton