If energy from waste is going to help power our towns of tomorrow it needs to be joined by carbon capture and storage. Sarah Kidner looks at where the technology is now, and where it needs to get to in the future.
Energy from waste (EfW) is a cornerstone of the circular economy. A 2020 Policy Connect report described it as ‘the best available option’ for disposing of the 50% of the UK’s waste that isn’t recyclable, while the technology has the potential to play a vital role in the race for net-zero.
The technology is steadily growing; just under 14 megatons (Mt) of residual waste was converted to energy in 2020, up 11.1% from the 12.6Mt processed in 2019. But before EfW can be found in every town and city, there are obstacles to overcome.
Dr Adam Read, President of the CIWM and Director of External Affairs for SUEZ, which operates nine EfW plants across the UK, agrees. ‘You’ve got to have the infrastructure,’ he said.
I wouldn’t want to be in Italy’s position a few years ago, where rubbish was piling up on the streets in Naples.
Read also points out that energy-from-waste technology has a serious image problem, which is stopping the technology from delivering all the benefits that it could. ‘Most people don’t want an EfW plant in their backyard, but if it’s not in their backyard then they won’t get the benefit of cheap local heat that comes with it,’ he says.
Feeling the heat
Dr Read makes a good point. The benefit of the cheap heat that an EfW can provide through local heat networks can’t happen if the incinerator is hundreds of miles away.
‘The big issue with Energy from Waste is incinerators,’ says Natascha Engel, Chief Executive Officer for Policy Connect. ‘Nobody wants to live near an incinerator; everyone thinks EfW is a great idea until it lands on their doorstep.’
This means waste often needs to be transported to remote, out-of-town facilities. SUEZ, for example, operates an EfW plant on the outskirts of Bristol that takes waste from West London, more than 100 miles away.
The company uses rail at night when the lines are under-used. ‘It’s quite a carbon-efficient form of transport, significantly better than lorries in and around London,’ Read said. ‘And, of course, the land prices in London mean you would never get a facility like that built in town these days.’
New towns, new tricks
But there are examples where EfW is already working well. One only needs to look at the many ‘new town’ developments across the UK, to see how EfW plants are already providing energy and heat directly to residents.
The Millerhill Recycling and Energy Recovery Centre (RERC) in Scotland is a good example. This ‘heat-off’ EfW plant aims to heat the nearby 4,000-home development of Shawfair, lowering the carbon footprint of the residents living there.
When waste arrives at Millerhill RERC, recyclable materials are first recovered and removed. What remains is then thermally treated to produce electricity and heat. In addition, it brings the temperature of the heat supply down to 50°C, making it easier to incorporate heat pumps.
These lower temperature heat systems are cheaper to operate than traditional gas heating systems and ‘represent a major step towards decarbonising heat supplies to buildings in the area’, according to Dr Paul Moseley, associate director at the Scottish Futures Trust.
Midlothian Council has signed a 40-year agreement to provide heat to nearby public buildings in Shawfair. The project is the first of its kind by Energy Services Company (ESCo), which the council owns jointly with Swedish energy company Vattenfall.
Another example of a community powered by EfW is the Energy Recovery Facility (ERF) in Sheffield – owned by Sheffield City Council and run by Veolia. This centrally located plant can handle 225,000 tonnes of municipal solid waste each year, generating up to 19MW of electricity for the National Grid.
That’s enough to power up to 19,000 homes. It also supplies up to 60MW of heat energy to the 140+ buildings connected to its local heat network. These include offices, leisure facilities, hotels, and houses.
Despite the success of EfW projects like those in Shawfair and Sheffield, centrally located heat-off solutions remain rare. ‘One of the big problems is the non-existence of heat networks,’ says Engel. ‘Something like 2% of homes are on heat networks, and that makes it difficult to feed them from an Energy from Waste plant.’
Policy Connect’s paper, No Time to Waste, says the UK is a long way behind the rest of Europe when it comes to using EfW heat in towns and cities. ‘Historically, UK policy has favoured the adoption of gas networks for heating and was, until recently, the world’s largest market for boilers,’ it finds. The paper also says that while most modern EfW plants follow a Combined Heat and Power (CHP) design in anticipation of finding a heat customer, only eight of the UK’s 40 EfW facilities were actually operating in CHP mode, as of 2018.
Decarbonising emissions
EfW is undoubtedly part of the solution to greenhouse gas reduction but, ultimately, incinerators still produce CO2 – according to some estimates 11Mt every year, with proposed and under-construction EfW plants adding an extra 9Mt.
To address this problem, Read says a massive technological step forward needs to be taken. ‘Carbon capture and storage will be the next big technology innovation to decarbonise emissions [from EfW],’ he says.
Indeed, carbon capture and storage (CCS) is something that interests Read and his colleagues at SUEZ very much. SUEZ is a crucial player in the East Coast Cluster, a government-backed initiative to deploy CCS across the Humber and Teesside regions. It’s one of the UK’s first carbon capture usage and storage clusters (CCUS) and aims to remove nearly half of all UK industrial cluster CO2 emissions – including those from EfW plants.
Additionally, in November 2020, SUEZ signed a memorandum of understanding with BP to explore Net Zero Teesside, the UK’s first decarbonised industrial hub. The agreement paves the way for carbon capture solutions at one of the four EfW facilities SUEZ operates in the Teesside area.
The company aims to use a solvent-based system to capture CO2 from flue-gas emissions. This will be sent to the Zero Teesside CCUS project, from where it will be transported and kept permanently in geological storage beneath the North Sea.
And SUEZ isn’t the only player innovating with CCS. Cory, which operates in London and the Southeast, also plans to apply CCS to its existing EfW operations.
In a bold statement, Cory says it will deliver the ‘world’s largest single-site EfW decarbonisation project’ and capture 1.5Mt of CO2.
The savings will include 90% of Cory’s existing EfW plant emissions plus emissions from a new facility, expected in 2026.
The plan also highlights the strategic importance of the river Thames, which could be used to ship CO2 from industrial facilities in the region to North Sea geological storage sites.
Dougie Sutherland, CEO of Cory, is excited about the technology’s potential: ‘Cory’s carbon-capture project could be game-changing. Not only would it be one of the largest CCS projects in the UK, but it would lead the way in using existing, natural infrastructure.’
Cory, working in partnership with Vattenfall, also hopes to create one of the largest district heating networks in the UK. The network would channel otherwise-wasted heat produced in the capture process to local homes.
While the combination of EfW and CCS has the potential to radically alter how we create energy, no such plants yet operate in the UK, leading many to wonder when, or if, we will see such technology in operation. But there is light at the end of the tunnel.
In March 2022, SUEZ’s Teeside plant progressed to Phase 2 of the government’s carbon capture utilisation and storage cluster sequencing process. Any CO2 captured at its four EfW process lines could be transported to the East Coast cluster and stored ‘from the mid-2020s’.
Similarly, Cory says it will deliver its 1.5 million tonne CO2 saving by 2030 and has notified the Planning Inspectorate that it will submit a Development Consent Order application.
This gives real hope that CCS from EfW plants could begin to make a welcome contribution to the government’s ambition to capture and store at least 50 million tonnes of CO2 per annum by 2035. Retrofitting existing EfW plants could save even more CO2, and let’s not forget that actually creating energy from waste in the first place avoids 200kg of CO2 for every tonne of waste diverted away from landfill.
Dr Adam Read described CCS as a ‘needs-must’ scenario. ‘It’s a way of making the residual waste issue more acceptable – after all, it’s a technology that reduces emissions,’ he said.
In the future, we may even be able to put the CO2 captured from EfW to good use. Although there is too much of it in the atmosphere, there is often a shortage of CO2 in the food-industry – particularly when natural gas, which is used in industrial CO2 synthesis, is in short supply. Captured CO2 could not only make up any shortfall but could also replace the environmentally unfriendly natural-gas route.
Other uses of CO2 include the manufacture of cement, plastics, and fibres. Future processes could even use it as a starting point for jet fuel.
Transforming CO2 from public enemy number one to a useful commodity would be a triumph of the circular economy. As 13 cross-party politicians say in Policy Connect’s No Time to Waste: ‘We must no longer simply bury or export the problem. Instead, we should, as other European economies do, treat residual waste as a valuable resource. Energy from Waste (EfW) is not the perfect long-term solution…[but] it is an essential part of the net-zero transition ahead of us.’
This feature first appeared in the May / June 2022 issue of Circular.
