Produzione e distribuzione di elettricità e calore
Electrification in Industry
Autors: Pierluigi Leone, Sonja Sechi, Antonio Calabrò
Production and Distribution of Electricity and Heat
Industry accounts globally for 29% of total final consumption, 82% of direct coal and 38% of direct uses of natural gas in final energy uses. From the point of view of the sector's energy mix, electricity accounted for 28% of final consumption in industry globally in 2019, 35% in Europe and 41% in Italy. A very significant share, estimated at about 45% of total consumption in industry (energy and non-energy), is linked to the production of heat at different temperature levels through the use of fossil fuels. Primary sources of fossil origin are also used for non-energy uses in industry. The use of fossil fuels in the industrial sector has therefore led to significant greenhouse gas emissions that in 2019 exceeded 6.5 billion tons of carbon dioxide equivalent, 450 million tons of carbon dioxide equivalent in Europe and 31 million tons in Italy with an energy intensity between about 30 and 52 gCO2/MJ. There is significant scope for greater electrification of the industrial sector, especially in terms of heat supply, which could contribute to the decarbonisation of production. In fact, it is estimated that about 40% of direct emissions in industry are related to the production of heat from the combustion of fossil fuels. Conversion technologies that allow heat to be produced at different thermal levels thanks to the use of electricity have been classified on the basis of three thermal levels. The supply of heat at low temperature (< 100 °C) which includes heat pumps operating up to a temperature of 90 °C, radio frequency and microwave technologies. The supply of heat at medium temperature (< 400°C), mainly in the food sector, paper production, non-metallic minerals, non-ferrous metals and chemical sectors and characterized by technologies for converting electricity into heat such as induction technologies, direct (resistance) and indirect (infrared) heating technologies, mechanical vapour recompression, electric boilers. The supply of heat at medium-high temperature (> 400 °C), with uses mainly in the chemical sector, in the non-metallic minerals sector, in the steel sector, non-ferrous metals through electrical appliances such as electric furnaces and combustion systems based on the use of hydrogen (hydrogen is introduced in this context as an energy carrier produced by the conversion of electricity from renewable sources).