But why are we burning rubbish at all? Well, even with everyone’s best efforts, there is waste that can’t be recycled – such as contaminated card, plastics and paper and some other types of plastic.. Today, it’s accepted that the best way to deal with this waste is to get as much benefit from the resource as possible, and that means energy-from-waste plants. While the design and technology used at a particular plant depends on specific factors such as the waste available, the conversion of existing coal-plants is an exciting option for the sector. 

Multiple benefits
Repurposing a disused coal-fired power station saves demolishing it – an expensive, difficult and potentially dangerous process. Instead, a station and its associated infrastructure can be reused, and jobs at the plant and in the wider community can be safeguarded.

A repurposed plant can also generate a lot of electricity. While typical energy-from-waste plants might produce from 10-50MW, a converted coal power station could generate in excess of 200MW. The Uskmouth Power Station project we’re working on with SIMEC Atlantis and RJM will export 220MW of baseload power to the grid for its expected two-decade lifespan. That’s a lot of power – enough for around 220,000 homes.

World-wide potential
With generation due to start in late 2020, Uskmouth is the proof of a concept that could soon be rolled out across the UK and beyond. Converted coal power stations like this would generate electricity from 100% waste-derived pellets. The Uskmouth pellet will consist of 50% biogenic material, which is carbon neutral to burn, and CO2 emissions from burning waste are lower than from burning coal.

Pellets for the Uskmouth project, which will be produced in a new, purpose designed plant next to the power station, are the result of a special research and development programme led by SIMEC Atlantis. The pellets can be used in different combustion systems with minimal conversion costs, enabling existing coal-fired power stations to be converted to combust 100% waste-derived fuel. With the conversion of Uskmouth expected to take 18 months following the completion of the front-end engineering and design WSP is currently undertaking, it’s a solution that’s relatively quick to get up and running.

A strong option
Not everywhere in the UK has a coal power station that’s ripe for conversion, and not everywhere needs an energy-from-waste plant on this scale. At WSP we work on smaller facilities too, such as those at Baddesley in Warwickshire and Bridgwater in Somerset. We also support the development and construction of specialist plants that use advanced conversion technologies, such as gasification, to turn waste into synthetic gas, where the mix of waste available makes this technology a viable option.

However, in the right circumstances, the prospect of turning coal power stations coming to the end of their life into giant energy-from-waste plants is a strong option. After all, why wouldn’t you want to extend the operating life of a valuable asset, reduce emissions and dispose of non-recyclable waste responsibly?

Brian Sibthorp: Director, Thermal Power – WSP

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