Schott has produced an optical glass with 100% hydrogen for the first time at its Mainz facility in Germany.

After successfully testing glass production with 100% hydrogen on a laboratory scale in 2023, speciality glass manufacturer Schott has now completed its industrial-scale application.

For three days, the manufacturer melted optical glass in a furnace using its new technology for the first time – exclusively heated by hydrogen, completely free of natural gas.

So far, Schott has been conducting its tests with grey hydrogen because green hydrogen, produced from renewable energies, is not yet available in sufficient quantities.

The large-scale test received excellent marks, and the quality of the glass is now being analysed.

Schott manufacturers over 100 types of optical glass for various applications, such as consumer goods and measurement technology, as well as optical systems in research and development.

Dr Lenka Deneke, Schott Project Manager, said: "The test with 100% hydrogen is pioneering work for the specialty glass industry. If the tests show that the quality of the glass is also right and the glass properties remain unchanged, hydrogen would indeed be a suitable technology option.”

She continued that the experience gained from last year's tank tests with an initial 35% hydrogen-by-volume tremendously helped with this success, but also said that there are still many unanswered questions requiring further research.

A permanent changeover would also require further long-term tests and a continuous supply via a hydrogen pipeline.

For the large-scale tub test with 100% hydrogen heating, the hydrogen tank at Schott in Mainz was filled three times – but with grey, not green, climate-neutral hydrogen.

Dr Frank Heinricht, Chairman of the Board of Management at Schott, said: "We deliberately decided to use it so that we wouldn't lose any time testing its technical feasibility. This is sufficient for our tests, but we urgently need green energy for climate protection.

"Companies from energy-intensive industries need to set the course for the fastest possible development of a functioning infrastructure for green electricity and green hydrogen in Germany. Then our commitment will pay off, for the climate and for the competitiveness of our industry."

In addition to its own investments, Schott receives financial support from various institutions for its developmental work in the field of hydrogen.