Hydrogen infrastructures

The transformation of the energy system, with the aim of achieving greenhouse gas neutrality by 2045, represents a significant challenge. Action is urgently needed in all demand sectors. The increasing share of renewable energies in electricity and heat generation means that suitable storage and sector coupling options are required for an efficient energy system design.
 

The National Hydrogen Strategy of the German federal government focuses on green hydrogen as a key building block to ensure that Germany's energy requirements are met in every sector despite overall climate-neutrality. The strategy shows that the use of green hydrogen, alongside energy efficiency and the direct use of renewables, plays a central role in the transformation of industry, the transport sector and the energy industry toward sustainability and climate neutrality. As is clearly explained in the National Hydrogen Strategy, the highly ambitious targets for all sectors, to be achieved by 2030 and 2045, cannot be met unless hydrogen and its derivatives are introduced into the system in significant quantities. This means that by 2030, from domestic production alone around 30 TWh or approx. 1 million tonnes of hydrogen per year must be managed and distributed. This figure will be considerably higher after the complete defossilization of the national energy system. An appropriate transportation and distribution network for this volume of hydrogen needs to be in place by 2030.

TransHyDE – Storage and transportation solutions for green hydrogen

The hydrogen flagship project TransHyDE, with its five research and four implementation networks, is working on the optimal design for hydrogen infrastructures to create the greatest possible efficiency and resilience. The technological focus of TransHyDE is the research and development of transport and storage options for gaseous and liquid hydrogen, ammonia and liquid organic hydrogen carriers (LOHCs). The results obtained will be integrated directly into roadmapping processes for the development of a hydrogen infrastructure by 2045, and for the closing of standardization, certification and regulatory gaps. The flagship project is coordinated by Fraunhofer IEG, among others.

Within the subproject on system analysis, the Fraunhofer institutes IEE, IEG, IFF, IKTS, ISE, ISI and SCAI are working to classify the various transport technology options within the overall system. This analysis takes account of the spatial and temporal development of supply, demand and connecting transport and logistics infrastructures for green H2 at national and EU level, as well as the resulting interactions with electricity infrastructures and other energy sources.

In the subproject on safe infrastructure, the Fraunhofer institutes IEG, IPM and IWM are developing concepts and methods for evaluating materials and components that come into contact with H2 gas, and their suitability for accident-proof and long-term use in a real H2 transport infrastructure. They are developing gas sensors and sensor systems to ensure the safety of H2 infrastructures and components and to test the sensor technology under near-real conditions on the test rig.

Fraunhofer ISE is researching an application-oriented, industrially feasible, safe and cost-effective technology for reforming ammonia, within the AmmoRef consortium.

Research into hydrogen pipeline coatings, fouling protection and optimized coating and adhesive systems for LOHC storage systems is the focus of Fraunhofer IFAM 's work in the TransHyDE Helgoland network.

Storage of hydrogen as a flexible option

Hydrogen storage is a decisive prerequisite for implementing the energy transition. This is because hydrogen can only be a flexible option if the time lapse between hydrogen demand and production can be compensated. Potential options for storing hydrogen include the geological subsurface as well as physical and chemical storage technologies. The hydrocarbon industry in Germany and around the world has been using the subsurface for decades to store large quantities of natural gas in the pores within rocks (so-called »pore storage«) or in salt caverns. A total of around 24 billion cubic meters of natural gas are stored underground in Germany. This means that Germany has the fourth largest storage capacity in the world after the United States, Russia and Ukraine.

In the »H2 research cavern« project, Fraunhofer IMWS is developing an H2 storage research platform for the industrial- scale underground gas storage of green hydrogen, in salt caverns at the Bad Lauchstädt site.

The project is part of the HYPOS research initiative. In the H2-Sponge project (»H2 storage potential of geological rock formations«), the prerequisites are being created for the safe underground storage of hydrogen in the pore space of rocks. Key issues are the geological requirements for storage, the prioritization of sites and the experimental investigation of rocks in contact with hydrogen. To this end, two innovative hydrogen test rigs are being developed to simulate the underground storage process. On the one hand, the long-term integrity of rocks in contact with hydrogen will be investigated in a mobile geochemical laboratory. On the other hand, experiments on transient storage and transport processes are carried out in a hydrogen permeameter and a hydrogen porosimeter.

The interaction of these test rigs enables a meaningful evaluation of potential hydrogen storage rocks and the leak-tightness of storage facilities. Other aspects under investigation are the strategic planning of monitoring concepts, for the seamless monitoring of all relevant processes, and the development of analytical methods to assess the integrity of hydrogen storage wells. The aim is to develop proposals for handling hydrogen in geological underground storage facilities, as well as suitable infrastructure and safety concepts

KuWaTa – Spherical hydrogen tanks

In the KuWaTa project at Fraunhofer HTL, spherical hydrogen tanks were developed from carbon-fiber-reinforced plastics (CFRPs) using isotensoid winding technology. The high-pressure storage tanks for gaseous hydrogen, with a diameter of 1.25m, are designed to store 40 kg of hydrogen at 700 bar. The spherical shape offers clear advantages over conventional cylindrical tanks. Due to the uniform stress distribution on the spherical surface, the wall thicknesses can be significantly reduced compared to conventional cylinder geometries. Larger quantities of hydrogen can therefore be stored with the same tank weight. The use of special, diffusion-inhibiting matrices and liners further reduces the mass and achieves additional weight savings. The ratio of tank weight to stored hydrogen is currently 15:1 in the automotive sector. With the spherical tank, a weight ratio of 5:1 is the target. The use of isotensoid fiber placement ensures that all fibers providing the reinforcement are placed almost equatorially in the direction of the circumference. As a result, the compressive load is optimally transferred to the fibers, enabling maximum exploitation of the high fiber strengths. The KuWaTa project developed a special winding algorithm for a 5-axis robot system. The uniform load on the tank surface was successfully demonstrated in burst tests.

Support for transformation processes

What will the transformation process toward a largely greenhouse-gas-neutral energy system in Germany look like in practical terms? On behalf of the Federal Ministry for Economic Affairs and Climate Action BMWK, experts at Fraunhofer ISI are modeling scenarios for a cost-optimized, safe and secure energy system, thus providing important guidance for discussions on the future path of the energy transition. Using the FORECAST demand model, they also investigated the demand side of the European energy system for the grid operators.

Developers, companies and investors also need more precise information on economic viability before they invest in hydrogen technology. Energy system modeling by Fraunhofer IEG and Fraunhofer ISE can provide reliable information – from hydrogen production costs, efficiency and hydrogen yield through to feasibility studies and yield assessments. The success of innovative energy technologies depends, among other things, on social, political and economic support.

Fraunhofer ISI is investigating the social acceptance of hydrogen technologies in the EU project HYACINTH. The H2-Chancendialog project at Fraunhofer IAO's Center for Responsible Research and Innovation aims to identify the innovation potential of social perspectives, in order to develop new hydrogen solutions collaboratively, with the involvement of different stakeholders.

From import to regional distribution

In order to meet its demand, Germany will need to import a large proportion of green hydrogen, including synthesis products, because renewable energy sources are only available to a limited extent in Germany. Under the leadership of Fraunhofer ISI, Fraunhofer IEG and ISE are developing a global hydrogen potential atlas as part of the HYPAT project. To this end, they are creating a comprehensive list of possible export and import countries, the associated hydrogen export costs and, for the first time, deriving the prices at which hydrogen could be traded globally. Emphasis is placed on export partnerships between equals – for secure, economical and ecologically sustainable production and supply.

In addition to a detailed survey of the global techno-economic potential and analysis of the hydrogen chains, the study includes the sustainable coverage of the partner countries' own energy demand, the achievement of their climate targets and compliance with specific sustainability criteria for the hydrogen economy. Besides identifying suitable source countries and import routes for the international supply of hydrogen, the development of the national hydrogen infrastructure is of key importance in bringing together regional producers and consumers of hydrogen.

Together with Fraunhofer ISI, Fraunhofer IEG was commissioned by the Brandenburg Ministry for Economic Affairs, Labor and Energy (MWAE) to develop the foundations for a hydrogen transport network in the state of Brandenburg. The aim of the feasibility study was to develop an overarching hydrogen network that connects regional hydrogen producers, storage facilities and end users, and that is integrated into a nationwide hydrogen infrastructure. Where possible, the focus was on retrofitting existing natural gas pipelines. The study is making a significant contribution to the practical implementation of the hydrogen strategy of the state of Brandenburg.