Series of articles concerning hydrogen: How can hydrogen be transported?
Everyone is talking about hydrogen at least since the national hydrogen strategy was adopted. Also at FfE, research is being conducted into the contribution of hydrogen to the future energy system. Current projects focus on the sustainable production, transport and use of hydrogen as well as on overarching issues of market development and business models.
This article is the fourth in a series of six articles that will be published successively in the coming weeks. In this series of articles, the most important aspects of hydrogen will be explained briefly, comprehensibly and compactly.
Overview of the topics in the series of articles on hydrogen
- History of hydrogen as an energy carrier
- How is hydrogen produced?
- Where will hydrogen be used?
- How is hydrogen transported?
- What contribution can hydrogen make to the energy transition?
- Overview of current hydrogen projects
Distances between hydrogen production and consumption on sites
This article deals with the question of how hydrogen can be transported. Hydrogen often cannot be produced economically where it is needed. For example, an area with a high demand may be less suitable for the cheap production of renewable energy. Additionally, hydrogen fueling stations often lack the requisite land space to economically produce the needed hydrogen on-site. Instead, it is possible to transport hydrogen produced within Germany much further than 100 km [1]. When production occurs in a different country or continent, implying hydrogen importation, it necessitates transportation over significantly longer distances.
Transport properties of hydrogen
Hydrogen has some special properties that influence its transportation. Under normal conditions, it is gaseous and very light. As a very volatile gas, it escapes quickly and must therefore be stored in particularly tight containers. Hydrogen possesses a gravimetric energy density that is three times higher than that of gasoline. This means that one kilogram of hydrogen contains around three times more energy than one kilogram of petrol.
At the same time, it has a very low volumetric energy density under normal conditions due to its low density. This means that a liter of hydrogen contains very little energy and requires a lot of space to transport. To partially avoid this, the hydrogen can be compressed or liquefied at extremely low temperatures. However, the latter in particular requires a lot of electricity [2].
Transportation by truck
Trucks can be used to transport hydrogen in both compressed and liquid form. Trucks are very flexible and can transport hydrogen to wherever it is needed. However, high costs are incurred for each individual journey. This is why they are particularly suitable for small quantities. For longer distances, transportation in liquid form tends to be cheaper [2].
Transportation by ship
Similar to liquid natural gas, large ships can also transport liquid hydrogen across the world’s oceans. This form of transportation is therefore particularly suitable for extremely long distances between coastal regions. At the same time, the problem of high losses for liquefaction remains [3].
Transportation by pipeline
As a gas, hydrogen can be transported to consumers via pipelines. There are already two major networks in Germany, in the Ruhr region and in the central German chemical triangle [4]. Transportation in pipelines is inflexible because they can only supply connected users. However, their construction incurs significant investment costs. After that, however, the running costs are low and the transportation of large quantities is possible. Another major advantage is the low energy losses [1].
One way to reduce the investment costs for new pipelines is to convert existing natural gas pipelines that are no longer needed. In view of the fact that natural gas consumption is likely to fall in the long term, there is an opportunity to benefit from this well-developed infrastructure [5].
Transporting energy in the power grid
If hydrogen from electrolysis is used, the energy can also be transported via the electricity grid. Power generators feed the electricity into the grid and consumers produce the required amount of hydrogen locally using electrolysis. This system is therefore very flexible, as the electricity grid is already very well developed in many parts of the world. However, if large amounts of electricity are needed to supply electrolysers, new transmission lines would be required. These are significantly more expensive than hydrogen pipelines [6]. Hence, this transportation route is more suitable in the initial stages of a hydrogen-based economy.
To overcome the issue of low energy density, hydrogen can be integrated into other chemical compounds. This makes sense if the new chemical is easier to liquefy. Liquid organic hydrogen carriers (LOHC) are particularly useful substances for this purpose. Hydrogen can also be processed into ammonia. As with the liquefaction of hydrogen, energy is lost during the injection and release of hydrogen from these compounds. The costs of the plants are also considerable. This means that this transportation option is more suitable for very long distances [3].
Current plans of the federal government
In the “National Hydrogen Strategy”, the German government outlines its plans for how the state can support the development of a transportation infrastructure. Domestically, its focus is on pipelines [7]. In order to develop suitable standards for hydrogen transportation, the German government is funding research in this area in the Trans4ReaL and TransHyDE projects, in which FfE is involved with many other partners.
Furthermore, the Federal Network Agency is undertaking a consultation process to ascertain how hydrogen networks should be regulated [8].
Plans of the gas network operators
The natural gas network operators are also already addressing the issue of building and converting hydrogen pipelines. In their current network development plan, they specify that almost 500 km of additional hydrogen pipelines could be expected by 2025. This initial expansion will primarily take place in Lower Saxony and North Rhine-Westphalia [9].
The network operators also presented a map showing which areas could be supplied by a well-developed hydrogen transportation network in the future [9].
More Information
- Trans4Real – Knowledge transfer of the living labs for the energy transition
- Welche strombasierten Kraftstoffe sind im zukünftigen Energiesystem relevant?
- eXtremOS-Findings: How do extreme scenarios affect the European energy system
Literature:
[1] D. Krieg, Konzept und Kosten eines Pipelinesystems zur Versorgung des deutschen Straßenverkehrs mit Wasserstoff, Jülich: Forschungszentrum Jülich, 2012.
[2] C. Yang und J. Ogden, „Determining the lowest-cost hydrogen delivery mode,“ International Journal of Hydrogen Energy, Bd. 32, Nr. 2, pp. 268 – 286, 2007.
[3] International Energy Agency, „The Future of Hydrogen,“ Paris, 2019.
[4] K. Ganz, T. Kern, T. Hübner und S. Pichlmaier, „Studie zur Regionalisierung von PtG-Leistungen für den Szenariorahmen NEP Gas 2020-2030,“ Forschungsgesellschaft für Energiewirtschaft, München, 2019.
[5] A. Wang, K. van der Leun, D. Peters und M. Buseman, „European Hydrogen Backbone,“ Guidehouse, Utrecht, 2020.
[6] Deutsche Energie-Agentur; ewi Energy Research & Scenarios, „dena-Leitstudie: Integrierte Energiewende,“ Deutsche Energie-Agentur, Berlin, 2018.
[7] Bundesministerium für Wirtschaft und Energie, „Die Nationale Wasserstoffstrategie,“ Berlin, 2020.
[8] Bundesnetzagentur, „Regulierung von Wasserstoffnetzen – Ergebnisse der Marktkonsultation (Stand: November 2020),“ Bonn, 2020.
[9] Fernleitungsnetzbetreiber Gas e. V., „Netzentwicklungsplan Gas 2020–2030,“ Berlin, 2021.
