Potential carbon emissions reduction related to the recovery of unutilised waste heat

The introduction of district heating will have a significant impact on the building services industry, from the architecture of a building to its operation. This technical note investigates a delimited portion of the potential of currently unutilised heat which has the possibility to supply district heating networks in the UK. The UK industrial sector, wastewater treatment facilities and the existing UK waste incineration plants all produce waste heat available in a temperature range suitable for extraction into district heating networks via commercialised techniques broadly used in other countries. This technical note presents a comparative literature review, comparing UK statistics and studies with performance data based on Swedish operational facilities. It finds 51.7TWh of currently unutilised heat could be recovered annually, with a significant associated emission decrease if incorporated into the heat supply of the UK building stock. A quantitative analysis is carried out to compare the identified potential with the current UK heat demand and the potential impact on the UK carbon emissions is estimated. The calculations indicate a reduction of 14% in the required UK total domestic heat supply, despite only including a limited fraction of the available waste heat potential. Practical application: This technical note serves to highlight and emphasise the large amount of available waste heat potential currently not utilised in the UK. By estimating the impact of waste heat utilisation and incorporation into district heating and heat networks in the UK, the technical note aims to fuel discussion around the further incorporation of waste heat to be utilised in the UK heat sector.