USING GREEN HYDROGEN CORRECTLY FOR THE MOBILITY TRANSITION
Hydrogen (H2) is an excellent energy carrier. It can be stored for any length of time and converted back into electricity when needed. Decentralized production also enables short transport distances. However, its production by electrolysis, in which hydrogen molecules are extracted from water using electricity, is energy-intensive. A prerequisite for a good life cycle assessment is therefore that sufficient electricity from renewable energy sources is available for electrolysis. In addition, production is primarily tied to water resources. For one kilogram of H2, including all secondary processes, 17 kg of fresh water are required. This rules out production sites that are sunny or windy but have little water.
Plannable mobility facilitates use of hydrogen
In order to establish the use of green hydrogen in the long term, it is not only the existing industrial utilization sectors, such as metallurgy, steel production and the chemical industry, that are relevant. Hydrogen mobility offers at least as much potential. There are already hydrogen filling stations for cars and trucks. Hydrogen-powered passenger trains are being tested. The development of hydrogen-powered ships is progressing at a tremendous pace. And there is also immense potential in aviation to reduce CO2 emissions through hydrogen-based technology. Here, however, further processes are needed to replace kerosene. Rail transport offers a major advantage in this context, where routes can be planned precisely in terms of route and refueling. This means that refueling can take place in a structured manner at suitable hubs. The same applies to plannable public transport, for example by bus. Plannable truck traffic also holds great potential for hydrogen-based energy supply - and, in perspective, free truck and car traffic as well. However, the more individual the mobility, the more complex it is to implement a supply network. This is because the network must be very dense in order to meet the demands of road users for spontaneous refueling.
Mobility is also supported in Wunsiedel. For this reason, a hydrogen filling station will be built in 2023 for heavy-duty transport, which will be able to draw from the Siemens hydrogen plant in Wunsiedel that recently - in September 2022 - went into operation. Up to 1,350 metric tons of green hydrogen will be produced there annually for decentralized use, which in turn will save around 13,500 metric tons of CO2. Talks are already underway about expanding the plant.
Hydrogen production contributes to grid stability
Hydrogen is to be produced primarily when a region has electricity surpluses from renewable energy sources. Conversely, local deficits in the power supply can also be remedied with the help of a hydrogen storage facility. The goal is thus to take a step further away from the global power grid toward a more local grid. This will increase the resilience of the power supply and achieve greater grid stability - in a climate-neutral way.
© Siemens AG
is Head of Energy Performance Services at Siemens Smart Infrastructure in Germany. In this role, he advises and supports many customers when it comes to making energy supply intelligent and sustainable. This has also been the case from the very beginning of the sustainability project of Stadtwerke Wunsiedel and with a now seven-year technology partnership that has achieved and implemented quite a bit.
Further information: www.siemens.de/smartinfrastructure