Industrial excess heat for district heating in Denmark

Abstract

Excess heat is available from various sources and its utilisation could reduce the primary energy use. The accessibility of this heat is however dependent amongst others on the source and sink temperature, amount and potential users in its vicinity. In this work a new method is developed which analyses excess heat sources from the industrial sector and how they could be used for district heating. This method first allocates excess heat to single production units by introducing and validating a new approach. Spatial analysis of the heat sources and consumers are then performed to evaluate the potential for using them for district heating. In this way the theoretical potential of using the excess heat for covering the heating demand of buildings is determined. Through the use of industry specific temperature profiles the heat usable directly or via heat pumps is further found. A sensitivity analysis investigates the impact of future energy efficiency measures in the industry, buildings and the district heating grid on the national potential. The results show that for the case study of Denmark, 1.36 TWh of district heat could be provided annually with industrial excess heat from thermal processes which equals 5.1 % of the current demand. More than half of this heat was found to be usable directly, without the need for a heat pump.

Holistic methodological framework for assessing the benefits of delivering industrial excess heat to a district heating network

“…11 The potential for increased usage of industrial excess heat in different countries, regions, or industrial sectors has been investigated in many studies. [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Most focus primarily on the potential usage of excess heat for district heating. 12,[14][15][16]18,19,25 Other opportunities for utilizing industrial excess heat include delivery to other industrial plants, electricity production in combined heat and power (CHP) plants, and low temperature applications such as greenhouses and fish farming.…”

Characterization and visualization of industrial excess heat for different levels of on‐site process heat recovery

“…Bühler et al 19 state, for example, that "the use of actual energy use data or excess heat amounts obtained from site-specific analyses has the highest accuracy" for assigning excess heat amounts to a given production unit. Bühler et al 19 state, for example, that "the use of actual energy use data or excess heat amounts obtained from site-specific analyses has the highest accuracy" for assigning excess heat amounts to a given production unit.…”

“…13 The advantage of such methods is that they are based on data that are relatively simple to obtain. Bühler et al 19 also relied on thermal process-related CO 2 emissions to allocate excess heat estimations for different industrial subsectors to individual production sites. The bottom-up approach originally suggested by McKenna and Norman 13 and further developed by Hammond and Norman 16 has been adopted in several more recent studies such as the work of Miró et al 17 Papapetrou et al 18 extended and updated the approach by adjusting the conversion factors suggested by Hammond and Norman 16 for the UK for the period 2000 to 2003 in order to be applicable for other EU countries in 2015.…”

“…This was achieved by applying ratios reflecting differences and development of annual, country, and sectorspecific energy intensity values. Bühler et al 19 also relied on thermal process-related CO 2 emissions to allocate excess heat estimations for different industrial subsectors to individual production sites. Their sectorial potentials for excess heat availability were estimated based on energy and exergy analysis, with an approach that relied heavily on access to comprehensive data for the distribution of fuels between different process categories and temperature levels in 22 Danish industrial sectors.…”

Analysis of possibilities to utilize excess heat of supermarkets as heat source for district heating

“…Bühler et al [6][7][8] have conducted economic analyses of the possibilities to use industrial excess heat from thermal processes for district heating. They considered spatiotemporal aspects and ensured the economic feasibility by comparisons to alternative heat sources for the DH network and to energy-efficiency measures, which would decrease the availability of industrial excess heat.…”