Test plant for SOEC stacks

Challenge

Currently, there is a strong focus on power-to-X, where X denotes green fuels or chemicals produced using electrolysis (and electrolysis technology) of non-fossil-based CO2, H2O, and N2. Dynamic PtX can help the ongoing transition to a non-fossil infrastructure, as it can alleviate the challenges of balancing the varying power production from wind and solar power with actual electricity consumption.

Three different electrolysis technologies are being investigated in relation to their applicability to PtX. Alkaline Electrolysis (AEC) is the oldest technology, but also the technology with the lowest efficiency. PEM electrolysis has a higher efficiency but is very expensive as platinum and iridium are used in the electrodes. High temperature electrolysis (SOEC) has the highest efficiency, but is also the least developed of the three technologies. SOEC can be done very cheaply as no precious metals are used in the cells.

In relation to the ongoing plans to establish an energy island “North Sea Wind Power Hub” where part of the produced electricity is used for PtX (e.g., for the production of fuel for the shipping industry), SOEC is particularly interesting as the technology can advantageously be placed out on the energy island. The high efficiency of SOEC results in a very small production of waste heat. And on the energy island, the waste heat cannot be used as well for e.g., production of district heating. By placing the PtX plant on the island, ships can anchor up at the energy island and refuel. At the same time, the requirements for the electrical cables that are to carry the excess power ashore are reduced.

Haldor Topsoe A/S is among the leading manufacturers of commercial high-temperature electrolysis stacks. In this project, we will perform current-voltage measurements on commercial TSP1 stacks from Haldor Topsoe A/S, to quantify how much the efficiency can be increased using pressurised operation. Haldor Topsoe’s motivation to participate in the project is to gain increased insight into the performance of HTAS TSP1 stacks under pressure.

DynElectro ApS is currently helping the Colorado School of Mines build a test set-up for pressurised testing of high temperature stacks. Over the past year, DynElectro, together with CSM, has made more than fifty current-voltage measurements on commercial stacks from Ceres Power. DynElectro contributes to the project by providing know-how on building test setups for pressurised tests of high temperature electrolysis stacks. DynElectro’s motivation is to build pressure test setups for general use by AAU, HTAS and DynElectro in later projects.

One of the existing challenges with SOEC technology is its relatively low service life. This is due to, among other things. that Nickel migration and coarsening. Noon Energy is developing a new type of battery, based on high-temperature electrolysis, and has developed a new type of Nickel-free electrodes. Noon Energy contributes to the project by manufacturing and supplying cells with these electrodes for electrolysis testing at AAU. Noon Energy’s motivation for participating in the project is to have the performance of the electrodes quantified, during pressurised operation.

Solution idea

Pressurised operation is an essential part of the maturation process for the electrolysis technologies, as pressurised operation simplifies and makes the PtX systems cheaper. Both AEC and PEM have demonstrated pressurised operation for larger plants. For SOEC, pressurised operation is only demonstrated at the laboratory level on pre-commercial stacks.

Problem owners

• Haldor Topsøe A/S
• DynElectro

Problem solvers

• Hydrogen Valley
• Noon Energi ApS
• Haldor Topsøe A/S
• DynElectro
• AAU – Aalborg Universitet