Finn Daugaard Madsen stresses, however, that the goal line is still far away, and that there is therefore still a great need for research and development.
“In the past, we have optimized the turbine to make it as good as possible. And we have optimized the electrolysis to make it as efficient as possible. Now the two things have suddenly been linked together, so we have to optimize both at the same time. There are countless things that need to be tested, and we need our research institutions to help us,” he says.
“Siemens Gamesa and DTU are dependent on each other. We are dependent on the many good people in our organizations who can drive development in the right direction.”
Testing new materials
One of the people Finn Daugaard Madsen is alluding to is Henrik Lund Frandsen, a senior researcher at DTU who works with ceramic electrolysis. He is in dialogue with Siemens Gamesa regarding the hydrogen project in Brande, and works with other major players such as Haldor Topsøe.
Henrik Lund Frandsen notes that the biggest challenge with Power-to-X on the energy islands is that the hydrogen-producing electrolysis plants have to operate using the wind turbines’ fluctuating power production. Or in sector jargon: they run off-grid.
Normally an electrolysis plant is connected to the common power grid, where the power supply is constant, so the electrolysis cells can continuously split water into hydrogen and oxygen.
On the energy islands, the electrolysis plants will not be connected to the common power grid, and if the right solutions to control the turbines are not developed, it could have an impact on the power supply to electrolysis, which risks fluctuating as much as the wind. This makes it difficult to maintain stable operation, and places great demands on the materials used in the plants.
“If there are long periods without wind, there will be no power to produce hydrogen, and ultimately the plants will have to be shut down. When they need to start up again, they must first be warmed up. This causes wear on equipment and is expensive, because high-temperature electrolysis occurs at temperatures between 600 and 850°C,” explains Henrik Lund Frandsen.
However, calculations show that hydrogen production on the energy islands still has great economic benefits. Hydrogen is seven to ten times cheaper to transport ashore than electricity, and this is a large part of the total cost.
Henrik Lund Frandsen is therefore researching which materials are the most robust to use in electrolysis, so that fluctuations in wind, power input, and temperatures will cause the least possible disruption to operations and wear on plants.
“As things stand now, the materials used in the plant are best operated at a temperature of 750°C. If the temperature drops below this, the ceramic cells that produce the hydrogen operate sub-optimally, and if the temperature goes above this, we put strain on the steel lids used in the plants. If the power level wanders up and down, the various materials wear on each other, reducing the service life,” says Henrik Lund Frandsen.
He expects DTU to be ready within three years to test a dynamically adapted Power-to-X plant, that can last for five years before components have to be replaced. Current systems can last for two to three years.