The EU-funded three-year NELLHI project has concluded after successfully developing a new stack design of solid oxide fuel cells, from an all-European supply chain.

Solid oxide fuel cells (SOFC) are considered the leading fuel cell technology, producing the highest efficiencies of any electrical generation, above combustion engines, gas turbines or other fuel cells.

Key applications for SOFC systems include residential combined heat and power systems (CHP), automotive vehicles and electrolysis. In an SOFC electrolysis system, fuel cells convert excess power from renewable generation to turn water into hydrogen, addressing intermittency and storage issues for wind and solar.

Key challenges such as high costs, production at scale and capital investment have hampered widespread deployment of SOFCs.

Participants of the NELLHI project report that their results address two of these concerns, in achieving the project’s main objectives, which were:

Developing high-performance SOFC stacks at low cost

Results showed more than 70% stack gross efficiency and excellent resilience towards load cycles. The project found its stacks were ‘ready for integration in any clean power-generating system and implementation in the energy market.’ Stacks were designed and assembled with optimised interconnections and seals.

Optimising high-performance cells with low temperatures

Stack performance depends on the electrochemical properties of its cells. European fuel cell manufacturer Elcogen developed an optimal microstructure using particular materials to decrease operational temperatures to 650 ˚C – compared to conventional temps of 750-800°C. Cell dimensions were also increased and Elcogen developed a highly reproducible route to increase mass production rates.

Newly patented game-changing seals

The NELLHI project developed and tested a new material formula for cell fuel cell seals. These gaskets are resistant to high temperatures and extreme atmospheres. The design was patented during the project and is now commercially available from UK company Flexitallic.

Enn Õunpuu, CEO of SOFC manufacturer, Elcogen, said, “We’re particularly excited by the potential applications for these stacks, including residential combined heat and power systems, which could replace hundreds of thousands of inefficient gas boilers across Europe. Solid oxide fuel cell stacks could also be a game-changer for renewables, with excess power from wind and solar being used to convert water into hydrogen, solving urgent issues around intermittency and storage.” 

Participants in the NELLHI project included Estonian fuel cell manufacturer Elcogen, Italian new technologies and energy agency ENEA, Finnish technical research centre VTT, UK engineered seal company Flexitallic, Belgian fuel cell component company Borit, Swedish engineering company Sandvik, and German institute for environmental technology CUTEC.