The great fuel-cell race

Atle Kjærvik

Several Norwegian industrial and research groups have thrown themselves into the global race to develop efficient, reasonably priced technology for converting natural gas directly into electricity. The driving force behind the Norwegian effort is the approximately 3,000 billion cubic metres of unexploited gas that lis hidden under the Norwegian continental shelf.

Sketch of a fuel-cell power plant.

We are talking about fuel cells. The most optimistic energy researchers believe that this technology can become the main component of the environmentally friendly power stations and vehicles of the future. High-temperature fuel cells can convert natural gas into electricity very efficiently and virtually without creating pollution. Small fuel-cell power stations and electric vehicles with fuel cells utilizing hydrogen and air (e.g. an experimental model from Daimler-Benz) are already in operation. As we might expect, Japan, the USA and Canada are leading the race, but that doesn't stop Norwegian companies and research teams at SINTEF/NTH from taking part.

Power stations of the future

Fuel cells exploit the chemical energy of the fuel very efficiently; about 50 -60%. If we include their heat utilization potential, the conversion efficiency rises to almost 80%. The comparable conversion efficiency of a typical thermal power station is about 40% excluding the heat production. And because the fuel is not combusted in the conventional sense, we virtually avoid all emissions of nitrous and sulphurous gases. SINTEF and Saga Petroleum A/S have shown that in comparison with a coal-fired power station, for example, pollution is reduced by more than 80%.

Fuel cells have no moving parts to wear out or cause energy losses. The heat produced by the process can be recovered by heat exchangers and used to heat water. A fuelcell power station is not liable to burn down or explode, is noiseless and can be built in a wide range of energy production capacities, according to requirements. The fuelcell power stations of the future can thus be located near consumers, thereby reducing power losses in transmission lines.

Japan in the lead

Low-temperature fuel cells using phosphoric acid as an electrolyte and hydrogen/oxygen as fuel are closest to commercialization. The biggest demonstration plant in the world, in Tokyo, uses cells of this sort. Toshiba can now supply cells of the type used in the demonstration plant. The plant has an output of 11 MW, sufficient to meet the energy requirements of about 5,000 Norwegian households. The drawback of this technology is that it is dependent on pure hydrogen for fuel, and cannot utilize natural gas directly in the process.

Graduate students Magnar Ottøy (nearest to camera) and Steffen Møller-Holst at NTH's Dept. of Physical Chemistry, are concentrating on low temperature polymer cells.

Norwegian effort

However, the solid oxide cells used by the (former) Norwegian NorCell project (now seeking foreign capital) may utilize natural gas. These cells use ceramic electrolytes (ceramics are materials such as glass and porcelain). The ceramics involved here are oxygen-ion conducting ceramics which are almost completely insensitive to contamination in the fuel. The natural gas can thus be fed directly into the cells without the need for an expensive purification process.

NorCell was a collaborative effort that involved Elkem Ceramatec, Norsk Hydro, Saga Petroleum and the Research Council of Norway. SINTEF and the Institute for Energy Technology were also involved in parts of the project. It was SINTEF's expertise in ceramics and catalytic processes in particular that brought them into the project. NorCell made a demonstration model last year, and intends to present a 2 kW prototype this year. A 200 kW unit should be ready by 1998. Within Norway, NorCell was in competition with the Statoil, Prototech A/S and the NTH/SINTEF so-called "Mjølner" project. This project is now the only Norwegian project of importance. The majority the Norwegian groups put their efforts into solid-oxide cells.

Two of the dr.ing. (Ph.D) students at NTH´ Department of Electrocheminstry, Gro Lauvstad (left) and Lennart Jerdal, with some of the equipment used in the Departments´ solid-oxide fuelcell-projects

Solar energy, hydrogen and fuel cells.

Fuelcell technology can also be used in conjunction with other environmentally friendly energy sources. Solar energy and electrolysis, for example, may produce hydrogen which in turn can be used in fuel cells. What are known as electrolyzers (reversed fuel cells) can also be used in purification and separation technology, for example, to produce pure oxygen from air. Related technologies can also produce petrol and oil from natural gas.

Boosted by space research

The fuel-cell principle has been known for more than 150 years since it was described by Sir W. R. Grove in 1839. Some sporadic research was done during the 30s, but it was not until the 50s that significant amounts of money were put into fuel-cell research. Their first application was during the Gemini and Apollo space missions. The moon landings, for example, would scarcely have been possible without fuel cells. Nowadays, the scarcity of fossil fuels and stricter environmental standards are what drive the research efforts