Switzerland

Hydrogen and its derivatives are important components to achieve climate policy goals especially in terms of greenhouse gas neutrality. There is an ongoing controversial debate about the applications in which hydrogen and its derivatives should be used and to what extent. Typically the estimation of hydrogen demand relies on scenario-based analyses with varying underlying assumptions and targets. This study establishes a new framework consisting of existing energy system simulation and optimisation models in order to assess the long-term price-elastic demand of hydrogen. The aim of this work is to shift towards an analysis of the hydrogen demand that is primarily driven by its price. This is done for the case of Germany because of the expected high hydrogen demand for the years 2025–2045. 15 wholesale price pathways were established with final prices in 2045 between 56 €/MWh and 182 €/MWh. The results suggest that – if climate targets are to be achieved - even with high hydrogen prices (252 €/MWh in 2030 and 182 €/MWh in 2045) a significant hydrogen demand in the industry sector and the energy conversion sector is expected to emerge (318 TWh). Furthermore the energy conversion sector has a large share of price sensitive hydrogen demand and therefore its demand strongly increases with lower prices. The road transportation sector will only play a small role in terms of hydrogen demand if prices are low. In the decentralised heating for buildings no relevant demand will be seen over the considered price ranges whereas the centralised supply of heat via heat grids increases as prices fall.

Proposals for achieving net-zero emissions by 2050 include scaling-up electrolytic hydrogen production however this poses technical economic and environmental challenges. One such challenge is for policymakers to ensure a sustainable future for the environment including freshwater and land resources while facilitating low-carbon hydrogen production using renewable wind and solar energy. We establish a country-by-country reference scenario for hydrogen demand in 2050 and compare it with land and water availability. Our analysis highlights countries that will be constrained by domestic natural resources to achieve electrolytic hydrogen self-sufficiency in a net-zero target. Depending on land allocation for the installation of solar panels or wind turbines less than 50% of hydrogen demand in 2050 could be met through a local production without land or water scarcity. Our findings identify potential importers and exporters of hydrogen or conversely exporters or importers of industries that would rely on electrolytic hydrogen. The abundance of land and water resources in Southern and Central-East Africa West Africa South America Canada and Australia make these countries potential leaders in hydrogen export.

The cost of polymer electrolyte water electrolysis (PEWE) is dominated by the price of electricity used to power the water splitting reaction. We present a liquid water fed polymer electrolyte water electrolyzer cell operated at a cell temperature of 100 °C in comparison to a cell operated at state-of-the-art operation temperature of 60 °C over a 300 h constant current period. The hydrogen conversion efficiency increases by up to 5% at elevated temperature and makes green hydrogen cheaper. However temperature is a stress factor that accelerates degradation causes in the cell. The PEWE cell operated at a cell temperature of 100 °C shows a 5 times increased cell voltage loss rate compared to the PEWE cell at 60 °C. The initial performance gain was found to be consumed after a projected operation time of 3500 h. Elevated temperature operation is only viable if a voltage loss rate of less than 5.8 μV h−1 can be attained. The major degradation phenomena that impact performance loss at 100 °C are ohmic (49%) and anode kinetic losses (45%). Damage to components was identified by post-test electron-microscopic analysis of the catalyst coated membrane and measurement of cation content in the drag water. The chemical decomposition of the ionomer increases by a factor of 10 at 100 °C vs 60 °C. Failure by short circuit formation was estimated to be a failure mode after a projected lifetime 3700 h. At elevated temperature and differential pressure operation hydrogen gas cross-over is limiting since a content of 4% hydrogen in oxygen represents the lower explosion limit.

Islands face limitations in producing and transporting energy due to their geographical constraints. To address this issue the ROBINSON project funded by the EU aims to create a flexible self-sufficient and environmentally friendly energy system that can be used on isolated islands. The feasibility of renewable electrification and heating system decarbonization of Eigerøy in Norway is described in this article. A mixed-integer linear programming framework was used for modelling. The optimization method is designed to be versatile and adaptable to suit individual scenarios with a flexible and modular formulation that can accommodate boundary conditions specific to each case. Onshore and offshore wind farms and utility-scale photovoltaic (PV) were considered to generate renewable electricity. Each option was found to be feasible under certain conditions. The heating system composed of a biomass gasifier a combined heat and power system with a gas boiler as backup unit was also analyzed. Parameters were identified in which the combination of all three thermal units represented the best system option. In addition the possibility of green hydrogen production based on the excess electricity from each scenario was evaluated.

Hydrogen is considered one of the key pillars of an effective decarbonization strategy of the energy sector; however the potential of hydrogen as an electricity storage medium is debated. This paper investigates the role of hydrogen as an electricity storage medium in an electricity system with large hydropower resources focusing on the Swiss electricity sector. Several techno-economic and climate scenarios are considered. Findings suggest that hydrogen storage plays no major role under most conditions because of the large hydropower resources. More specifically no hydrogen storage is installed in Switzerland if today’s values of net-transfer capacities and low load-shedding costs are assumed. This applies even to hydrogen-favorable climate scenarios (dry years with low precipitation and dam inflows) and economic assumptions (high learning rates for hydrogen technologies). In contrast hydrogen storage is installed when net-transfer capacities between countries are reduced below 30% of current values and load-shedding costs are above 1000 EUR/MWh. When installed hydrogen is deployed in a few large-scale installations near the national borders.

The seasonally varying potential to produce electricity from renewable sources such as wind PV and hydropower is a challenge for the continuous supply of hydrogen for transport and mobility. Seasonal storage of energy allows to avoid the use of grid electricity when it is scarce; storage systems can thus increase the resilience of the energy system. For grid-neutral and renewable hydrogen production an electrolyser is considered together with a Power-to-Gas seasonal storage system which consists of a methanation the gas grid as intermediate storage and a steam reformer. As feed stream electricity from an own photovoltaic (PV) system is considered and for some cases additional electricity from the grid or from a wind turbine. The dynamic operation of the plant during a year is simulated. It is possible to safely supply fuel cell vehicles with hydrogen from the grid-neutral plant without using electricity when it is scarce and expensive. To supply 135 kgH2/day unit sizes of 1 MW–2.9 MW for the PV system and 0.9 MW–2.6 MW for the electrolysis are required depending on the amount of available grid-electricity. The usage of grid-electricity increases the capacity factor of the electrolysis which results in decreased unit sizes and in a better economic performance. Seasonal storage of energy is required which results in an increased hydrogen production in summer of approximately 50% more than directly needed by the fuel cell vehicles. The overall efficiency from electricity to hydrogen is decreased due to the storage path by 10%-points to 56% based on the higher heating value. Assuming a cost-equivalent hydrogen price per driven kilometre in comparison to the actual diesel price and electricity costs of 10 Ct/kWhel from the grid the revenues of the system are higher than the operating costs.

To inject green hydrogen (H2) into the existing natural gas (NG) infrastructure is one way to decarbonize the European energy system. However asset readiness is necessary to be successful. Preliminary analysis and experimental results about the compatibility of hydrogen and natural gas mixtures (H2NG) with the actual gas grids make the scientific community confident about the feasibility. Nevertheless specific technical questions need more research. A significant topic of debate is the impact of H2NG mixtures on the performance of state-ofthe-art fiscal measuring devices which are essential for accurate billing. Identifying and addressing any potential degradation in their metrological performance due to H2NG is critical for decision-making. However the literature lacks data about the gas meters’ technologies currently installed in the NG grids such as a comprehensive overview of their readiness at different concentrations while data are fragmented among different sources. This paper addresses these gaps by analyzing the main characteristics and categorizing more than 20000 gas meters installed in THOTH2 project partners’ grids and by summarizing the performance of traditional technologies with H2NG mixtures and pure H2 based on literature review operators experience and manufacturers knowledge. Based on these insights recommendations are given to stakeholders on overcoming the identified barriers to facilitate a smooth transition.