Fuel cells presently require an order of magnitude cost reduction to become a commercial success in domestic energy markets. Previous analyses using learning curves have shown that competitive costs are feasible, but these have been unanimously based on theoretical estimates. Empirical price data is presented for polymer electrolyte fuel cell CHP systems installed in Japanese homes between 2004 and 2008. Experience curves are fitted to this data, taking account of the number of systems produced before and during this period The p g p. e average unsubsidised price of a 0.7-1.0 kW system is (sic)3.33 M (sic)23,000) as of early 2009, and has fallen by 19.1-21.4% for every doubling in production. These empirical experience curves predict that prices will fall below (sic)10,000AW once 6090 thousand units are sold; but that tens of millions of units are required before they reach cost targets of around (sic)1000/kW. Even with rapid deployment, attaining unsubsidised economic viability before 2025 will be challenging. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.