Germany has embarked on a groundbreaking journey towards finding an efficient and cost-effective solution for storing green energy.
A German research consortium, along with companies Zn2H2 GmbH and Steel PRO Maschinenbau GmbH, is spearheading the Zn-H2 project, aiming to develop a cutting-edge electricity storage technology that could power the nation with renewable energy over extended periods. The project combines zinc storage with alkaline water electrolysis, paving the way for a unique and promising solution that could revolutionize the energy transition era.
As Germany pushes forward with its ambitious energy transition, the need for effective energy storage technologies becomes increasingly evident. While renewable energy sources like wind and solar have become economically viable, the challenge lies in storing this green energy efficiently to ensure a reliable and uninterrupted power supply. Presently, fluctuations in electricity generation caused by wind lulls and solar dark doldrums require compensation from conventional power plants, limiting the full potential of renewable energy.
The Zn-H2 project seeks to address this challenge by developing a long-lasting battery designed explicitly for long-term energy storage. Drawing inspiration from existing zinc anode battery solutions, the researchers are integrating this technology with alkaline water electrolysis to create a novel storage system. Unlike conventional lithium batteries, zinc storage offers significant advantages: it is cost-effective, utilizes readily available raw materials (steel, zinc, potassium hydroxide), and is fully recyclable. Moreover, the technology enables the on-demand production of hydrogen, providing a versatile and efficient energy storage solution.
Explaining the chemical process within the battery, Dr. Robert Hahn from Fraunhofer IZM, who coordinates the project, says, “During charging, water in the battery oxidizes to form oxygen, while zinc oxide is reduced to metallic zinc simultaneously. When the storage cell is discharged, the zinc reverts to zinc oxide, and in the process, hydrogen is produced and released.” The result is an innovative fusion of battery and hydrogen production, achieving an impressive overall electricity storage efficiency of 50%, surpassing the current power-to-gas technology.
One of the most significant advantages of the zinc-hydrogen storage system is its cost-effectiveness. With material costs less than a tenth of a lithium battery, it holds the promise of economically attractive green energy storage. The researchers have already validated the core concept of the technology in the laboratory, conducting efficiency and stability tests on individual cells.
The consortium plans to create a demonstrator by the year’s end, initiating research on operational management in a test stand. The Fraunhofer IZM team in Berlin is responsible for designing the demonstrator, setting up the test stand, and conducting reliability tests. As the zinc-hydrogen storage technology is unprecedented, the team is developing an intelligent control system to adjust and optimize various parameters for the best performance.
While further upscaling and refinement are needed before the technology becomes commercially viable, Zn2H2 GmbH has already filed patents associated with the project. The consortium’s pioneering efforts and dedication to developing innovative energy storage solutions lay the foundation for a greener, more sustainable future, supporting Germany’s commitment to a carbon-free energy grid by 2035 and achieving net-zero emissions by 2050.
