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.
Heat supply for buildings
In Germany, about 75 % of the heat supply for public and private buildings is currently provided by natural gas. Due to the long life cycles of heating systems, gas is likely to remain a central energy source in the building sector in the medium to long term. Furthermore, existing buildings in urban areas in particular are difficult to convert to alternative, low-CO2 heating systems such as electric heat pumps.
The application of green hydrogen is an option to replace fossil natural gas and to reduce greenhouse gas emissions in the building sector. For instance, hydrogen can be mixed with natural gas and burned in gas condensing boilers connected to the pipeline network. Provided the necessary adaptation of the infrastructure (e.g. pipelines and heating systems), a gradual increase in the proportion of hydrogen in natural gas is conceivable.
In addition to the co-combustion of hydrogen in gas condensing boilers, the use of hydrogen can also take place in stationary, decentralised fuel cell heating systems for domestic energy supply. Especially in the case of a complete conversion of the gas grid or certain districts to hydrogen, such fuel cell heating systems can be a reasonable alternative to gas condensing boilers. The electricity generated by the fuel cells in addition to the heat (keyword: combined heat and power) can either be used to supply the households themselves or fed into the grid. Fuel cell heating systems are already offered by various suppliers and are mostly based on PEM fuel cells.
The application of green hydrogen is an option to replace fossil natural gas and to reduce greenhouse gas emissions in the building sector. For instance, hydrogen can be mixed with natural gas and burned in gas condensing boilers connected to the pipeline network. Provided the necessary adaptation of the infrastructure (e.g. pipelines and heating systems), a gradual increase in the proportion of hydrogen in natural gas is conceivable.
In addition to the co-combustion of hydrogen in gas condensing boilers, the use of hydrogen can also take place in stationary, decentralised fuel cell heating systems for domestic energy supply. Especially in the case of a complete conversion of the gas grid or certain districts to hydrogen, such fuel cell heating systems can be a reasonable alternative to gas condensing boilers. The electricity generated by the fuel cells in addition to the heat (keyword: combined heat and power) can either be used to supply the households themselves or fed into the grid. Fuel cell heating systems are already offered by various suppliers and are mostly based on PEM fuel cells.