The heat generated by industrial activity is a recoverable, carbon-free energy source, but still largely under-exploited.
We call fatal heat thermal energy produced during the operation of certain production or transformation processes which is not used. Indeed, many industrial processes require heat for their operation. This heat is partly lost, whether in the form of hot air, cooling water, or even mist, smoke or steam of processes.
Ademe is campaigning massively in favor of the recovery of industrial waste heat: in fact, waste heat is carbon-free, since it is produced “anyway”, and could become a significant source of energy. THE figures published by the agency show the considerable energy resource constituted by industrial waste heat: no less than 109.5 TWh of waste heat rejected by industry as a whole, which corresponds to 36% of its fuel consumption. Figures that give food for thought, given the French and European objectives in terms of decarbonization of industry.
Beyond the figures, several questions arise for manufacturers wishing to recover their heat.
First, for what purpose. An industrial player may want to recover waste heat to reuse it internally, to save heat on other processes. This makes it possible to improve the energy performance of the industrial process. The only downside, but a significant one, is that the investments to create these installations are often very significant, even if they are profitable in the long term.
Recovered industrial waste heat can also be sold externally, to meet the heat needs of other companies or other users, for example through a heating network.
Incinerators and data centers are installations that particularly emit heat, and which would therefore benefit from implementing heat recovery and recovery strategies. In fact, incinerators accumulate 4.37 TWh and data centers 3.61 TWh of waste heat. More broadly, the industrial sectors or the waste heat deposit are the most “promising”, as a percentage of the 109.5 TWh mentioned above, are theagri-food (31%), the chemicals/plastics sector (22%), and the paper/cardboard activity (13%)… We will also mention metallurgical activities and non-metallic materials.
In France, the heat fund led by Ademe has already enabled some 7,100 companies and communities to benefit from financial aid for the installation of heat recovery systems. These heat recovery systems will vary, depending on the nature of the heat-generating industrial activity, and other parameters, which also depend on the destination of the recovered heat.
Today, the most common installations for using waste heat from an industrial site and supplying it elsewhere are heat networks. The latter are very energy efficient, and can make it possible to develop industrial synergies on the territory covered by the heating network. This may particularly concern large areas of industrial activity, where companies are located relatively close geographically. The local exploitation of these waste heat deposits can serve both industries, public installations and individuals, each with specific uses.
Beyond the local synergies generated by heat recovery, the potential effect of massification of industrial waste heat recovery is considerable, both ecologically and in terms of autonomy and economy. Indeed, the recovery of industrial waste heat would make it possible to reduce energy imports, and thereby our energy dependence. This would also have favorable consequences on the French trade balance.