Turn up the heat on energy from waste

London – Energy-from-waste (EfW) facilities must use their heat potential to maximise efficiency and carbon dioxide emissions savings, Nick Dawber, managing director of UK-based Energos said at the recent Waste to Energy City Summit in London.

The event brought together technology developers and waste management companies with the city’s financial community and policy-makers to identify emerging investment and development opportunities in gasification and pyrolysis for municipal and industrial waste.

Dawber told the audience that EfW plants should exist within the heart of industrial and residential communities to utilise the heat value of the waste instead of wasting this renewable, low cost energy resource.

“To achieve higher levels of efficiency we need to sell heat - either directly as steam to industrial customers to displace existing fossil fuel supplies - or as combined heat and power (CHP),” he said. “When the ratio of energy used is two parts heat to one part electricity, facilities will achieve up to 50% efficiency, which rises to as much as 85 % if you utilise the full heat potential.”

It is necessary, he explained, to develop smaller efw plants to capitalise on heat potential since there are more available sites for small facilities, which can be located close to the potential demand for heat and are appropriately sized to satisfy that heat requirement.

There will be higher public acceptance for ‘community sized’ facilities, the MD believes. Smaller plants minimise traffic to the site and can sit alongside recycling facilities to provide a local solution for local non-recyclable waste while delivering a renewable supply of low carbon, low cost energy.

Dawber called on the government to accelerate the development of district heat networks, as demanded under the EU Energy Efficiency Directive, to avoid valuable heat resources being wasted.

He stated that a large 400,000 tonnes per annum EfW plant, producing around 32MW of electricity, would have a surplus of around 70MW of heat that is normally lost to the atmosphere because there are very few industrial facilities that have sufficient CHP demands for large-scale EfW.

“Small-scale facilities … can supply usable amounts of energy (up to 20MW of heat) to local customers,” he said. “Apart from the efficiency benefits, such plants also qualify as a ‘recovery’ plant under the EU Waste Framework Directive and stand to benefit from the UK’s Renewable Heat Obligation.

“Another approach is to provide a new commercial or residential development with an EfW plant to meet its carbon neutral requirements and satisfy planning conditions. Energos is partnering with UK developers to integrate local waste treatment infrastructure with low carbon energy supply for such developments.”