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Industrial excess heat may often be utilised for district heating and thus replace existing expensive or CO 2 -emitting technologies. Previous works analysed the distribution of excess heat by temperature intervals and their geographical distribution relative to district heating areas. A more detailed analysis of the most suitable types of industries and the costs is required, allowing a targeted exploitation of this resource. This work extends the spatial and thermodynamic analysis, to account for the temporal match between industrial excess heat and district heating demands, as well as the costs for implementation and operation of the systems. This allows the determination of cost-effective district heating potentials, as well as the analysis of different industries and technological requirements. The results show that the temporal mismatch between excess heat and district heating demand and lack of demand, reduces the theoretical substitution potential by almost 30%. If heat storages are introduced, the total potential is reduced by only 10%. A majority of the excess heat can be utilised at socio-economic heating costs lower than the average Danish district heating price and the cost of solar district heating. Excess heat from oil refineries, building material and food production can be utilised at the lowest specific costs. [ABSTRACT FROM AUTHOR]

Large-scale heat pumps (HPs), biomass CHPs and excess heat (EH) from industry and data centres are promising district heating (DH) sources. Electricity and thus power transformers (PTs) will be an important part of the future energy system, which opens the possibility to use the thermal losses occurring in PTs for DH. The present paper analyses high voltage PTs in Denmark as DH sources. First, we employ a thermodynamic model of PTs to determine the EH they produce. Subsequently, we analyse thermodynamic properties of heat exchangers and HPs necessary to utilise EH for DH. Finally, we perform a GIS analysis to link the PTs with specific DH networks. From the theoretical amount of excess heat from power transformers (EHPT) available for DH of 0.28 TWh per year, 0.12 TWh or 0.5% of Danish DH demand can reach the consumers. 0.07-0.21 GWh can reach the consumers below the average DH price. The entire EHPT potential can be utilised through HPs, working with an average COP of 4. The sensitivity analysis showed that the EHPT can supply up to 2.26% of the Danish DH demand. Therefore, EHPT is a relatively small DH source on the national scale but could be an important local option. [ABSTRACT FROM AUTHOR]

Excess heat is present in many sectors, and its utilization could reduce the primary energy use and emission of greenhouse gases. This work presents a geographical mapping of excess heat, in which excess heat from the industry and utility sector was distributed to specific geographical locations in Denmark. Based on this mapping, a systematic approach for identifying cases for the utilization of excess heat is proposed, considering the production of district heat and process heat, as well as power generation. The technical and economic feasibility of this approach was evaluated for six cases. Special focus was placed on the challenges for the connection of excess heat sources to heat users. To account for uncertainties in the model input, different methods were applied to determine the uncertainty of the results and the most important model parameters. The results show how the spatial mapping of excess heat sources can be used to identify their utilization potentials. The identified case studies show that it can be economically feasible to connect the heat sources to the public energy network or to use the heat to generate electricity. The uncertainty analysis suggests that the results are indicative and are particularly useful for a fast evaluation, comparison and prioritization of possible matches. The excess heat temperature and obtainable energy price were identified as the most important input parameters. [ABSTRACT FROM AUTHOR]