An estimate of the ultralow waste heat available in the European Union

• Published in: Energy (Oxford) Vol. 238; p. 121967
• Main Authors: Luberti, Mauro, Gowans, Robert, Finn, Patrick, Santori, Giulio
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.2022; Elsevier BV
• Subjects: Electric power generation; Emitters; Energy intensity; Energy sources; EU energy resources; Exergy; Heat; Heat recovery; Industrial areas; Metals; Minerals; Point sources; Process efficiency; Quantitation; Thermal energy; Ultralow waste heat; Waste heat; Ultralow waste heat; Process efficiency; Heat recovery; Thermal energy; Energy intensity; EU energy resources
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2021.121967

A large amount of low grade heat is wasted at temperatures below 100 °C but its quantity remains mostly unknown. Therefore, the identification and quantitation of low grade heat availability enables further assessments on whether or not the recovery of this fraction of heat is convenient. By considering the countries composing the European Union (EU), this work quantifies the low grade heat from power generation and industrial sectors (mining, minerals, metals, chemicals, pulp and paper, food) with a particular focus on the faction of heat below 100 °C. The analysis shows that, in the year 2018, 8774.4∙106 GJ (2437.3 TWh) of heat was available in the EU below 100 °C, with the power generation sector accounting for 95% of the total low grade heat emitted. In addition, around 96% of the waste heat was in the temperature range from 25 °C to 80 °C, being of ultralow grade. Similar conclusions were obtained in terms of exergy loss, which was essentially from the power generation sector, especially in the range of temperatures between 40 °C and 60 °C. These results suggest that ultralow waste heat is an untapped source of energy which can be conveniently exploited by the same point-source emitters, primarily in the power generation sector or in wider industrial areas where infrastructure is present. •8774.4∙106 GJ of heat below 100 °C in EU are from power generation and industrial sectors.•Largest fraction (7847.2⋅106 GJ) of ultralow heat in EU is between 40 °C and 60 °C.•The greatest contributor to ultralow grade waste heat is the power generation sector.•An exergy amount of 733.5∙106 GJ is available from ultralow grade waste heat.