Temporarily store excess wind in hydrogen
How can surplus wind energy be stored efficiently in the form of hydrogen in a large scale? Scientists consider the value chain from a technical and economic point of view in the project WESpe. The Analysis includes electrolysis, underground storage facilities and the connection to gas grids.
|Project status||Near completion|
|Typical system size (Energy)||Up to 85 GWh (cavern storage capacity)|
|Typical system size (Output)||0,5 bis 20 MW (electrolyser)|
|Volumetric energy density||300 Wh/l (@ 100 bar cavern pressure)|
|Efficiency (AC/VNH2)||< 4,4 kWh/Nm3 (alkaline electrolyser), < 4,3 kWh/Nm3 (PEM-electrolyser)|
|Response time when preparing the energy||< 10 s (from operating temperature condition)|
|Project duration||December 2013 until December 2017|
The research project aims to promote the integration of hydrogen storage in the energy sector in order to pave the way for an energy supply based on renewable energies. Several components of wind-hydrogen systems will be studied in order to prove the technical and operational feasibility. For the first time the technologies of the PEM electrolysis and alkaline electrolysis side by side are investigated in a project. In addition the optimization potential along the entire value chain are determined to infuse into subsequent generations of technology.
Systems for the conversion of fluctuating excess wind energy into hydrogen with various options of temporary storage and application fields represent highly complex systems that have not yet been realized technically in this scale and this scope. Consequently a series of new technical detail problems in the area of basic research, systemic general issues, problems of environmental protection and social acceptance requiring scientific study. The objectives are both the scientific treatment of these detailed problems and general issues for the technical optimization of the electrolysis and the wind-hydrogen systems under real conditions. Likewise, the objectives are the identification of suitable locations and the analysis of direct interactions between wind power generators and gas grid under the conditions of the accelerated expansion of renewable energies.
Optimization and Economy
The identification and implementation of potentials for performance and efficiency of central components of wind-hydrogen systems (especially alkaline and PEM-electrolysis) is based on theoretical studies, fundamental experimental work and scientific preparation of the results from the practical work. Furthermore, the development of methods for location and risk assessment of power-to-gas plants and their peripherals and infrastructure shall be undertaken. In parallel, the knowledge base is extended for the underground gas storage of hydrogen in terms of interactions with the surrounding rock, the integrity of the drill holes and above-ground equipment. Another component is the development of simulation tools based on the modeling of wind-hydrogen systems for the analysis of system and operational performance. In addition the interactions of the gas and electricity network when coupled with hydrogen systems are studied. Finally climatic, environmental and efficiency benefits of storing hydrogen and suitable measures to strengthen public acceptance of hydrogen as a storage medium will be determined.
A focus of the project is the optimisation fo technical components of wind-hydrogen-systems aiming on durability and better performance. Consequently a better economics is expected. Due to the close cooperation of the research consortium with the industrial companies of the project support committee, the prognosis for the successful implementation of future wind-hydrogen projects and further utilization is considered very good. Thus there are promising opportunities for industrial companies to enter new markets at an early stage with high export potential.
Stages of the project
1st stage: Creation of a preparatory study on location analysis and verification of framework conditions and of the technical implementation of wind-hydrogen projects.
2nd stage: Scientific Research with different performance characteristics and test routines focusing on the further development of the central components of a wind-hydrogen system and to accelerate the optimization of processes and technologies in the industry.
3rd Stage: Scientific Research for comprehensive integration of wind-hydrogen systems in the energy system and economic challenges.
Development of methods for the evaluation of sites: The research project begins with a basic work package for method development regarding general principles for the suitability of sites and general analysis and evaluation of the technical, economic, legal approval and funding policy risks. Furthermore a coarse screening of suitable operating models are carried out.
WP1 - Evaluation of the core components: Fundamental investigations on alkaline and PEM electrolysis under the new conditions of the dynamic operation.
WP2 - Requirements on underground storage: The focus is on the identification of methods and design principles that allow the construction of technically and economically optimal and reliable feeding systems and in the evaluation and optimization of new materials and components for the transport and distribution of hydrogen and hydrogen-containing gases. Key aspects are system security and storage performance in both porous rock storage as well as storage caverns. Content of the work is also the development of exploring and monitoring programs for hydrogen underground gas storage.
WP3 - modeling and functional approach: The focus of the work package is further developing of the electrolysis technology and the entire H2-energy chain from wind power to CGH2. For this purpose, the dynamic modeling of alkaline and PEM electrolysis systems and other auxiliary components as well as an accounting of the annual values such as total annual utilization rate and efficiency takes place.
WP4 - Environment and climate protection: study of the effects on the environment and climate protection in terms of greenhouse gas balances, of preventable natural gas imports, the use of land (avoidable electrical grid expansion) and the environmental relevance of materials from electrolyzers.
WP5 - Studies on the acceptance and transparency: The work package addresses the development and testing of a communication concept. In parallel for the development of the communication concept is to be found a most appropriate partner for a wind-hydrogen energy storage demonstration project. It is essential to solve general issues related to environmental protection and social acceptance in the realization of large-scale hydrogen storage for the predominantly renewable energy system. It aims to develop a methodology for the communication of power engineering and political contexts for better regional anchorage of Energiewende-infrastructure-projects that will simplify the testing and implementation of future storage technology projects.
WP6 - System analysis and economic considerations: Systems analysis and economic studies with a holistic view supplement scientific research.