Mitsubishi Heavy Industries Ltd. , which has developed the world's smallest fuel cell system for supplying power to households, intends to make its system even smaller before commercialization, the company's top engineer for the system said in a recent interview with Jiji Press.

Shigeru Nojima, who heads the polymer electrolyte fuel cell development team at the Japanese firm's Hiroshima Research & Development Center, noted that for a fuel cell to gain wide household acceptance, it needs to be the size of a home electric appliance.

A fuel cell is an environmentally friendly device that generates electricity and heat through a chemical reaction between hydrogen and oxygen via an ion-conducting electrolyte. Mitsubishi Heavy's polymer electrolyte fuel cell system is 100 centimeters high, 60 centimeters wide and 30 centimeters deep. It is the world's smallest one-kilowatt class PEFC system.

The invention comes at a time when city gas suppliers, oil distributors and machinery makers are busying themselves with feasibility tests on fuel cell systems for households amid expectations that many Japanese homes will be equipped with fuel cell cogeneration systems for supplying power as well as hot water by around 2010.

The Japanese companies expect to commercialize their technologies sometime around next spring.

But the high cost of fuel cells is one major hurdle facing the companies.

Nojima said, "It will likely take more time to bring down the price of fuel cells to near 500,000 yen, which is seen as a crucial level for the spread of fuel cells." "But once specifications on fuel cells are established, the production cost will fall sharply," he said.

Nojima also noted that because fuel cell components such as the fuel reformer are handmade at present, each part costs as much as 50,000 yen. "If mass production starts, the price will likely drop to about 200 yen," he said.

Nojima also said that Mitsubishi Heavy is looking for materials that can replace expensive platinum and ruthenium for use in catalysts that cause chemical reactions in the system. Since the world's annual output of platinum is a mere 160 tons, the amount of platinum used in catalysts has to be reduced to a hundredth of the current amount or smaller, he said.

While pointing out that a fuel cell can double energy efficiency at home by producing hot water and electricity at the same time, Nojima predicted that in the future, households will be able to produce power with a solar battery in the daytime, by wind power generation equipment when the wind blows, and with fuel cells at night.