Hydrogen has been on everyone’s lips since the adopted national hydrogen strategy at the latest. Research into the contribution of hydrogen to the future energy system is also being carried out at the FfE. Current projects focus, among other things, on the sustainable production, transport and use of hydrogen as well as overarching topics of market development and business models.
This article is the fifth in a series of six articles that have appeared in recent weeks. In this contribution series, the most important aspects of hydrogen are explained briefly, comprehensibly and compactly.
The paper deals with the role of hydrogen in the future energy system in the context of ambitious emission reduction targets. It highlights the effects that the use of hydrogen can have on the integration of renewable energies and the shift away from fossil fuels. Due to the high degree of interconnection, it makes sense to address the issues at the European level.
Hydrogen as a seasonal energy store
As already mentioned in the third article in this series, not all applications in the final energy sectors can be technically electrified. Furthermore, there are applications where it can make economic sense to use hydrogen instead of electricity. Thus, a deep decarbonisation of all sectors also requires hydrogen as an energy carrier. But the conversion of electricity to hydrogen in electrolysis can also be advantageous in energy supply, despite the associated losses. The eXtremOS project shows that hydrogen functions primarily as a seasonal storage medium in a sustainable energy system.
Thus, the renewable energy capacities to be installed for the winter months produce more electricity than needed in the summer. This electricity is converted to hydrogen and used as soon as necessary in the industry and transport sectors. There is thus a temporal decoupling between generation and consumption. In 2050, 1,085 TWh of hydrogen is produced in the solidEU scenario (for reference: total final energy consumption in Europe in 2017 was 13,682 TWh). The storage capacity needed to shift hydrogen production is 170 TWh.
Renewable energy and hydrogen are very compatible
The use of green hydrogen as a final energy carrier results in a high electricity demand due to conversion losses in electrolysis. Therefore, “more hydrogen” always means “more renewable electricity”. However, the analyses also show that these renewable energies can be better integrated and used and thus also have a higher profitability.
This effect is amplified in the event that the investment costs of electrolysers fall more than assumed. In this case, more photovoltaic plants are added, especially in southern countries (France, Italy, Spain), in order to produce hydrogen with the electricity generated. The lower full-load hours compared to wind energy weigh less heavily with lower electrolysis costs. This means that electrolysers can also be operated with fewer full-load hours and have an even stronger focus on optimising operating costs (or electricity costs).
The additional electrolysis capacities that are built due to lower electrolysis costs have lower full load hours, but the production volume of hydrogen remains almost the same. As a result, technologies that produce other products based on hydrogen, such as synthetic fuels or synthetic methane, have higher full load hours and are therefore more profitable. In this case, more synthetic fuel and more synthetic gas is produced.
FitFor55 – higher installed electrolyser capacity needed for 2030
The two scenarios shown each achieve a greenhouse gas reduction of 55 % by 2030 compared to the base year 1990 and are thus consistent with the plans of the EU Commission. However, at 62 GW, the electrolyser capacities to be installed in the EU are significantly higher than the declared target of 40 GW. The situation is similar in Germany, where 8 GW of electrolyser capacity will be built by 2030 in the solidEU scenario. The declared German target of the national hydrogen strategy is 5 GW.
Keeping an eye on time scales – using hydrogen correctly
Hydrogen has the potential to reduce GHG emissions even in those applications that are difficult to decarbonise. These sectors, such as the steel industry, must have the certainty that hydrogen will be available when they switch to it. The fact that blue hydrogen must be used for this in the short term should not be an obstacle, but it must be supplemented with clear transition paths to green hydrogen. Moreover, it is clear from this that hydrogen will still be available in limited quantities in the short to medium term. Accordingly, it remains essential to concentrate hydrogen applications on those areas that rely on it.