The challenges of EfW facilities in the UK

Written by: Kathryn Warrell and Mark Terrell | Published:
Triden Park EfW facility in Cardiff

Waste management consultants Kathryn Warren and Mark Terrell from Ricardo Energy & Environment discuss what the real challenges and costs of operating EfW facilities in the UK.

EfW boom or bust?

It would seem that EfW is currently booming in the UK given that 2016 saw an 18% increase in the amount of residual waste being processed through energy recovery plants in the UK. At the start of 2017 there were 41 operational EfW facilities in the UK, with 18 new facilities due to be commissioned this year.

Most of the EfW plants now operational in the UK were developed with investment under the Public Private Partnership (PPP)/Public Finance Initiative (PFI) regime, but now that regime is behind us, what impact does this have on the future economic viability of EfW and what other financial challenges is the industry facing?

In this article, we examine issues such as revenues, gate fees, incentives and costs, and how they impact on the real challenges of operating an effective EfW plant. If we could have a £1 for every time someone asked us for capital and operational costs of an EfW, well, we’d almost have enough to build one ourselves. In reality, these costs vary significantly depending on technology, scale, contract type, business model and feedstocks.

As mentioned above, the majority of EfW facilities developed in the UK over the last 20 years have been those procured by local authorities in order to meet landfill diversion targets and provide affordable, long term residual waste solutions. There are exceptions with merchant EfW facilities such as Grundons/Viridor at Colnbrook, but these are few and far between. Secure, long-term contracts are attractive both to funders and developers. However, many local authorities are no longer considering long-term contracts for EfW facilities, in light of challenges across the UK about their affordability, flexibility and appropriateness, so what are the new challenges for the industry?

Subsidies

For many years PPP/PFI has helped local authorities create new waste EfW facilities. Now that this funding source has stopped, the focus of the sector had already begun to shift to opportunities to develop merchant facilities targeting commercial and industrial waste such as SSE Ferrybridge and the Hoddesdon gasification plant.

There is no doubt that there is plenty of C&I waste on the market, with the 2016 Defra Waste Statistic quoting 27.7 million tonnes of C&I waste generated in the UK. Yet as this cannot be guaranteed in long term contracts, other incentives are needed to off-set the risk. Previously, fiscal incentives such as Renewables Obligation Certificates (ROCs) were seen as a driver, but only EfW with Combined Heat and Power (CHP), or Advanced Thermal Conversion Technologies (ACT) such as gasification were eligible and therefore this had limited impact for most plants.

Its replacement, the Contracts for Difference scheme (CfD), could play an important role in the future development of EfW, but EfW will need to compete with other renewable energy technologies. While a handful of EfW with CHP/ACT projects were successful in the first round, it is not surprising to see an increasing number of plants being taken forward that aim to succeed without a reliance on subsidies.

Brexit?

It has been reported that Brexit is already driving up the cost of developing EfW facilities in the UK. This is due to a number of factors, including increasing costs due to exchange rates, and higher specialised construction labour costs. However, the main reason is the purchase of boilers and other key components of EfW plant / equipment from outside of the UK. The exchange rate has simply made the purchase of an EfW plant more expensive.

Equally the change in exchange rate has now made the export of Refuse Derived Fuel (RDF) more expensive, which should in time drive more waste producers to seek UK based options for the future. EfW in the UK has had to compete with RDF exports, which have historically been cheaper than landfill or EfW. However, the increased prices for RDF appear to be here to stay making UK EfW more attractive post Brexit, which should result in an upturn in UK infrastructure development.

EfW Operations

Conventional EfW technology is tried and tested, but what happens when the feedstock that you designed the plant for is not what is actually being delivered to the bunker? Waste composition is evolving, as both our consumer habits and recycling practices change. For example, additional food recycling is increasing the residual waste calorific energy value, as has been the case in Scandinavia. Generally, EfW facilities operate within a reasonably wide window of throughput versus calorific value of waste, but significant changes in either will require careful process control.

In recent years, there has been no fundamental changes to the technology used at the majority of EfW plants, but there has been significant improvements in EfW performance. There is now greater control over the combustion process and its emissions. The plants are much more robust with most plants operating at higher than 90% availability. More heat is being recovered with initiatives such as flue gas heat recovery and lower parasitic loads are also improving overall energy efficiency, particularly in EfW-CHP plants.

Higher efficiencies can present its own challenges however. Higher steam temperatures will result in higher efficiencies but this does mean a higher risk of corrosion, particularly of the boiler tubes in the furnace and super heaters. Higher levels of chlorine in the waste, coupled with higher steam temperatures, also results in increase boiler corrosion. Regular cleaning is required to prevent fouling which caused reduced heat exchange and lower efficiency.

Energy from waste with CHP is the most efficient use of energy (perhaps as high as 70% thermal efficiency compared to 35% for combustion & energy recovery facilities), but comes with its own set of challenges and barriers. In conventional EfW, when steam is exhausted from the turbine, much of the energy is dissipated into the atmosphere and lost. With CHP schemes, some of the steam is extracted after it has given up most of its useful energy. This steam is then condensed in a heat exchanger, and the remaining energy captured as hot water, increasing the overall energy efficiency conversion of the process. However, extracting steam from the turbine for CHP does reduce the overall electricity generation potential. For example, extracting 5MW of heat will typically reduce the electricity generation by 1MW.

Therefore, while a plant may benefit from greater overall efficiency, this can have a significant impact on the economic model of the plant. This, coupled with higher capex costs, could explain why there is still not a significant uptake of EfW CHP in the UK. Developers will need to secure a large enough ‘anchor’ load for the heat, and be able to sell the heat at a price that will overcome the loss in power sales. The lack of adequate incentives for EfW-CHP has also been a barrier.

Operational costs are certainly impacted on by economies of scale, and it is accepted that smaller plants will require higher than average gate fees. The relative cost per tonne to build and operate a large EfW facility ~300,000 tonnes per year will be much cheaper than a smaller facility. This is evident in WRAP’s recently published 2017 annual gate fee report, which shows a huge range of £50 to £144 per tonne for post-2000 EfW facilities.

Funding

Conventional EfW is often considered the only ‘bankable’ thermal waste treatment technology, due to it being robust, reliable with multiple reference plants and numerous technology providers. However, to secure investment in excess of £200 million pounds for suitably sized EfW facility is not an easy task. The key element to securing investment is a long-term waste supply contract.

While EfW is a cost-effective alternative to landfill in the UK with landfill prices currently greater than £100 per tonne, securing long term (10-year+) fixed price contracts for waste is very difficult. Many waste companies either do not want to take the risk on long-term contracts or they are simply too small to guarantee the value of a long-term contract. The funding risk for EfW and securing long term waste contracts will need to change to sustain the growth for investment in EfW facilities.

Summary

There are many factors to consider for new EfW facilities including funding, securing contracts operational costs and plant performance. There is a huge challenge in building and operating an EfW which is becoming more difficult due to factors such as Brexit and changes to government funding. Therefore, it is critical for companies building and operating EfW facilities to ensure they have considered all issues thoroughly and to maximise any opportunity to reduce costs and create value; to continue to increase plant efficiencies, to maximise heat and electricity usage and utilise C&I waste together with municipal waste.

More EfW infrastructure is still needed and asking the right questions up front will ensure the right plants are designed and built to meet today and tomorrow’s challenges head on.


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