When Energiepark Mainz opened in Germany earlier this month, the facility came online as the world’s largest eco-friendly hydrogen plant.
It took one year and 17 million euros ($18.7 million) to build the plant, which is a collaboration between utility company Stadtwerke Mainz AG, gases and engineering company Linde Group, technology group Siemens AG and the RheinMain University of Applied Sciences.
It addresses a major concern critics frequently cite against hydrogen fuel cell vehicles (FCVs): the carbon emissions of production plants. While using hydrogen as a fuel doesn’t create any tailpipe emissions, some are concerned with the way hydrogen is collected. Current techniques often pull hydrogen from natural gas, emitting carbon dioxide in the process.
Energiepark is different because it draws power from four nearby wind parks, using renewable energy to create hydrogen from water. A portion of this hydrogen will be transported to fueling stations for the public.
“Today, most of the hydrogen that Linde supplies to filling stations is already ‘green’,” said Linde CEO Dr. Wolfgang Büchele. “Energiepark Mainz has the capacity to produce enough hydrogen for around 2,000 fuel-cell cars,” said Büchele, though he didn’t clarify the time frame for this production level.
We reached out to Linde to find out more about the plant’s hydrogen production capabilities.
“As the electrolysers (more or less) continuously produce hydrogen and fuel-cell vehicles continuously consume it, time is not really a factor here,” said a representative with the company. “In any case, we figure to produce some 200 tons of hydrogen per year (which is not the maximum capacity) which would be sufficient for 2,000 cars with an assumed mileage of 10,000 km [6,214 miles] per year.”
Andreas Opfermann, head of research and development for Linde, also noted that hydrogen plants like Energiepark are essential for the proliferation of FCVs.
“The whole thing only works if we have three steps: the generation of the hydrogen, the refueling, and the cars. We are in a better situation than battery cars where every country has its own plugs, its own level of voltage. We now have standard fueling stations,” he explained.
In addition to providing fuel for FCVs, Energiepark can augment the natural gas grid. But it’s the facility’s ability to store hydrogen that is especially meaningful – this will capture excess renewable energy that would otherwise be wasted.
“Already today, wind and solar power stations have to be switched off at certain times if they produce too much energy for the grid,” explained Linde. “This problem is set to increase over the coming years as the renewable energy network expands.
“Energiepark Mainz can use this ‘surplus’ electricity to break water down into oxygen and hydrogen. The resulting environmentally sound hydrogen can be stored and then used at a later date when demand is higher. This process will enable renewable energies to be harnessed more flexibly to dynamically meet fluctuations in demand.”
As the first hydrogen plant of its size, Energiepark is also set to become a learning facility. The RheinMain University of Applied Sciences is planning a four-year research project at the plant to identify hydrogen extraction methods that can be applied elsewhere.
“At Energiepark Mainz, we can experiment with converting wind energy into hydrogen on an industrial scale and find out which operational concepts are the most viable,” said Prof. Birgit Scheppat, the head of the university’s hydrogen lab. “Being able to cost-effectively and sustainably harness energy from fluctuating sources such as wind and solar power is an important long-term goal. We expect this initiative to deliver exciting, ground-breaking insights that will help us move toward this key goal.”
What isn’t clear is what portion of the energy for hydrogen production will come from renewable resources. The facility is also connected to Stadtwerke Mainz’s medium-voltage grid, and is set to supply clean energy to the utility company. But it isn’t apparent if energy can also flow from the grid to Energiepark when wind farms aren’t producing.
It’s also worthy to note that the hydrogen slotted for FCVs also may not be completely emission-free, with tankers sourced to deliver the fuel to retail stations.