This document outlines specifications for solid oxide electrolyser stacks that could be coupled with wind turbines or nuclear power. Haldor Topsøe A/S is responsible for analyzing a scenario where power is supplied by wind turbines, looking at optimal operating strategies based on Danish electricity price data. Helion is studying a nuclear power-based case, using its parent company Areva's expertise. There are differences between the wind and nuclear scenarios but specifications for lifetime, current density, and degradation rate of the electrolyser stacks are similar. The detailed specifications and a comparison to other electrolyser technologies will be presented.

1. Specifications for Solid Oxide Electrolyser Stacks to be coupled with
Wind Turbine and Nuclear Power
Thomas Nietsch
Helion
Domaine du Petit Arbois, Bâtimet J. Verne, BP 71
F-13545 Aix-en-Provence Cedex 4
France
E-mail: Thomas.Nietsch@helion-fuelcells.com
John Bøgild Hansen
Haldor Topsøe A/S
Nymøllevej 55
2800 Lyngby
Denmark
E-mail: jbh@topsoe.dk
Abstract
SOEC has considerable potential as electrolysers as the thermodynamics favour high
temperature operation. A considerable of the energy input can be in the form of heat
enabling very low electricity consumption for hydrogen production.
Topsøe and Helion are participating in the CEA coordinated European RTD project
RelHY where one of their roles is to provide specifications for Solid Oxide Electrolyser
(SOEC) Plants.
Topsøe is responsible for a scenario where the power is supplied from wind turbines
whereas Helion is studying a nuclear power based case.
For the wind turbine case actual hourly electricity price data from Denmark have been
analysed in order to determine the optimum operating strategy for the SOEC units with
respect to on line hours, capacity utilisation etc.
For the nuclear scenario Helion has used the extensive know how of its parent company
Arreva for definition of the optimum strategy for massif hydrogen production.
There are considerable differences between the two scenarios.
Despite these difference the specifications with respect to lifetime, current density,
degradation rate etc. are remarkably similar.
The detailed specifications will be presented, explained and compared to state of the art
electrolysers as well as steam reforming based units. The systems integration will be
rapidly discussed.