Linde AG

Green light for green hydrogen at Energiepark Mainz - Seite 2

to the market," explains Dr Wolfgang Büchele. "If this technology is
adopted on a wide enough scale, it has the potential to significantly
reduce traffic-related environmental pollution. Today, most of the hydrogen
that Linde supplies to filling stations is already 'green'. Energiepark
Mainz has the capacity to produce enough hydrogen for around 2,000
fuel-cell cars".

In the project, Linde is responsible for purifying, compressing, storing
and distributing the hydrogen. The company's innovative ionic compressor
technology ensures that the compression process is extremely energy
efficient, giving the plant a high degree of operational flexibility. The
hydrogen produced in Mainz-Hechtsheim will be stored on site and partly
loaded into tankers to supply hydrogen fuelling stations. Some of the
hydrogen will also be fed into the natural gas grid for heating or power
generation.

Siemens delivered the park's hydrogen electrolysis system. This highly
dynamic, PEM-based high-pressure electrolysis system is a technological
highlight of the Mainz plant, clearly setting it apart from other,
significantly smaller pilot projects. With a peak performance of six
megawatts, it is the largest system of this kind in the world. The energy
park therefore has enough capacity to prevent bottlenecks in the local
distribution grid and to stabilise the power supply of smaller wind parks.

"The energy systems of tomorrow will be much more complex, integrated and
flexible than they are today. The PEM electrolyser is an important building
block in the new energy mix," elaborates Prof. Siegfried Russwurm at the
opening. "Hydrogen electrolysis is a great way to feed renewable energies
in particular more efficiently into power grids. It can be used to
dynamically capture, store and harness energy that is not currently needed.
We have developed an innovative system at Energiepark Mainz that can help
turn a vision into an industrial-scale reality."

The energy park is directly connected to the medium-voltage grid of the
Stadtwerke Mainz Netze GmbH utility company. It is also linked to four
neighbouring wind parks that belong to the Stadtwerke group. "We have many
years of experience as a grid operator. Across the Group, we are aware of
the benefits - but also the drawbacks - of renewable energies. We know just
how important it is to find further storage technologies for electricity,"