4.4 Hydrogen for Electricity and Heat
Today, the provision of electricity and heat is responsible for more than half of the total CO2 emissions in Germany (see chart in Section 1.2). As described in Section 4.1, the chemical energy stored in hydrogen can be converted into heat and electricity using direct combustion or fuel cell technology. If green hydrogen is used, heat and electricity are climate-neutral. In this chapter, you will learn about various use cases for which green hydrogen could become more important in this context in the future.
Generation of process heat
Process heat describes heat that is used for the production, further processing or refinement of products. The provision of process heat is therefore primarily relevant for industrial processes and could be considered part of this sector too.
Almost all products of daily use contain materials or components whose production requires high temperatures. While some areas of industry, such as food processing or mechanical engineering, largely require process heat at a temperature level of below 500 °C, there are other areas, such as glass and ceramics production or the processing of stones and soils, that need high-temperature heat in the range between 500 and 3,000 °C. This high-temperature heat accounts for around two-thirds of the total process heat demand in industry and is currently provided predominantly by fossil fuels.
In addition to energy sources such as biomass or renewable electricity, also green hydrogen can be used to provide process heat, especially at a high-temperature level, in a climate-neutral way. For this purpose, the hydrogen can be combusted directly in appropriate burners or heating boilers. Under certain circumstances, the use of high-temperature fuel cells (SOFC) is also possible, which at least enable the provision of heat at a temperature level of up to 700 °C.
Almost all products of daily use contain materials or components whose production requires high temperatures. While some areas of industry, such as food processing or mechanical engineering, largely require process heat at a temperature level of below 500 °C, there are other areas, such as glass and ceramics production or the processing of stones and soils, that need high-temperature heat in the range between 500 and 3,000 °C. This high-temperature heat accounts for around two-thirds of the total process heat demand in industry and is currently provided predominantly by fossil fuels.
In addition to energy sources such as biomass or renewable electricity, also green hydrogen can be used to provide process heat, especially at a high-temperature level, in a climate-neutral way. For this purpose, the hydrogen can be combusted directly in appropriate burners or heating boilers. Under certain circumstances, the use of high-temperature fuel cells (SOFC) is also possible, which at least enable the provision of heat at a temperature level of up to 700 °C.