PRODUCTION COST ESTIMATION OF SOLID OXIDE FUEL-CELLS

Production costs of two types of solid oxide fuel cells (SOFCs) were estimated to clarify their economical prospects. In this assessment 2000 kW of SOFC capacity is assumed to be manufactured per month. Single cells of a planar type with 0.21 W/cm2 are fabricated by co-firing of doctor blade layers and the separators are prepared by firing of press-moulding bodies. Stacks with 400 W consists of 20 cells and 21 separators. The materials cost of this type covers nearly 60% of the total (118 000 yen/kW). By comparison, the tubular SOFCs with 0.18 W/cm2 are assumed to be made using an electrochemical vapour deposition (EVD) method or a plasma spraying (PS) method on porous support tubes. The module with 20 tubes is built up by arranging the cells in a suitable order. The support tube is fired after continuous isostatic pressing. Including the cost of support tubes, the overall costs for tubular cell systems by the EVD method and by the PS method are about 617 000 yen/kW and 293 000 yen/kW, respectively.