A multi-megawatt fuel cell is to be developed to power offshore oil and gas platforms. As yet fuel cells are only capable of a few hundred kilowatts, but the new technology could work at 10 times that level.
At present many offshore platforms generate power by burning some of the natural gas they extract from under the seabed in a turbine.
Now Siemens Westinghouse, which is working for Shell on the project, proposes to use solid oxide fuel cells which convert natural gas into hydrogen without the need for a reformer, but with a CO2 by-product.
Though these would not be a wholly renewable emission-free resource, Shell Norway’s Sustainable Technology Development manager, Helge Skjaev- eland, stressed that this could still be ‘a major step’ in the transition to a hydrogen society. By placing the fuel cell in conjunction with a turbine system, it can produce pure CO2 that in turn can be ‘captured’ for other uses in oil extraction.
The turbine would exploit the hot exhaust gases from the cell to generate additional electricity and also pressurise the solid oxide fuel cell. Furthermore, a second cell dubbed an ‘afterburner’ could be configured to tap off excess fuel and energy from the first.
Key technical challenges for the fuel cells themselves will be reducing size and weight. Present technology would make them about 10 times larger and heavier than existing offshore power turbines. Skjaeveland said that pressurising the cells and reconfiguring the internal parts could offer more kilowatts per kilo.
It is likely that Siemens Westinghouse would have to build new manufacturing facilities, as the company doesn’t yet have the capacity to build cells on the projected scale. However, ceramic tubes already in production for solid oxide cells would be interchangeable between normal and large-scale models.
The project is being run in collaboration with Norwegian partners Aker Kvaerner and Statkraft. Aker Kvaerner’s head of gas technology, Oscar Graff, said the megawatt fuel cells could have applications onshore – whether integrated with an electricity grid or providing power for separate local users.
The projects was announced by Shell Group vice-chairman Jeroen van der Veer at the World Hydrogen Energy Congress in Montreal this week. A demonstration system could be ready for trials by 2005-2006.