Hydrogen fuel production by electrolysis
In a study, scientists are determining the theoretical prerequisites for testing an integrated overall system at an industrially relevant scale. For the “electricity – hydrogen – large-scale storage – usage” system, principles are being developed that are intended to identify as many risks as possible for the implementation.
|Project status||Study is nearing completion|
|Project duration||November 2012 until May 2014|
|Typical system size Energy||ca. 1000 MWh / 20000 MWh|
|Typical system size Output||5 MW / 100 MW|
|Efficiency AC/AC||Part of the results of the study|
|Efficiency AC/VN H2||< 4,1 kWh/Nm3|
|Typical period between storage and withdrawal||strongly dependent on way of usage|
|Example application areas||Fuel for transportation, industrial use, use at home, reconversion|
In the form of a study the theoretical conditions for the testing of an integrated overall system "Renewable energy - Hydrogen - Large-scale storage - Use" are investigated in industrial relevant dimensions. For this purpose, water electrolysers as a key technology are investigated in order to indentify possible technological risks in the implementation and assessment of these systems. This work will be complemented by work in the field of salt cavern storage and analysis of existing salt caverns as well as accompanying studies on the potential and technological requirements of the electricity supply from renewable energy sources. This serves as the basis for a chemical storage of renewable energy to compensate for the fluctuating yields and thus provides a basis for the availability of hydrogen as an energy carrier and fuel of the future.
Potential of the technology
In addition to the general studies on the integrated system "Renewable energy - Hydrogen - Large-scale storage - Use", in economically relevant dimensions a very specific electrolysis system is designed and rated for different services. The objective is to evaluate the potential of the technology in large systems. Similarly, concrete salt caverns locations in different states are analyzed. In addition, an economical analysis of the overall concept is performed.
Hydrogen can either be re-converted or directly used
In connection with the increasing installed capacity of fluctuating renewable energy, storage technologies for electric power are increasingly becoming the focus of industrial and political interest. A promising possibility are chemical storage technologies, such as hydrogen storage, associated with the production of hydrogen from (preferably renewable) electricity using water electrolysis. These can store an oversupply of fluctuating electrical energy, e.g. from wind turbines, as hydrogen. This allows the storage of large amounts of energy. The stored hydrogen can then either be re-converted at a later time or directly used such as fuel for the transport sector, as a chemical feedstock, or for households by mixing the hydrogen into the public natural gas grid.
The project can be roughly divided into three sections: a period of familiarization and mutual coordination; a second phase in which several scenarios are simulated and discussed; and a final evaluative phase. Currently, the project is at the transition between phase 1 and 2 (i.e. first calculations and technical assessments are being done).
Besides the knowledge for development potential of the involved technologies, the optimization of the overall concept (consisting of dynamic power delivery, generation of hydrogen using electrolyzers, large-scale hydrogen storage in salt caverns and hydrogen use) is the goal of this study. For this purpose, scenarios are modeled and simulated, based on technical considerations. The results thus obtained should contribute to the economic viability of the development of a hydrogen infrastructure.
Economic viability and durability
The production of hydrogen from electrolysis is more expensive compared to steam reforming of fossil natural gas. Since this technology can make an important contribution to the storage of renewable energy and usage in the energy system, a detailed analysis of the cost reduction potentials of electrolysis technology is necessary, including its long-term durability, the analysis of the optimal installation (centralized / decentralized) and the detailed analysis of the storage potential in salt caverns is necessary .