GOING GREEN AT HOME
Fuel Cells Cut Carbon Dioxide Emissions (February 24, 2005)
One of the next-generation technologies for producing clean energy is now available to ordinary households for the first time. Fuel cells are well known as an eco-friendly way of powering cars, but now, backed by the government, several Japanese companies have begun marketing home-use fuel cells that generate electricity from hydrogen and oxygen and help to cut carbon dioxide emissions. These devices take the form of combined water heaters and electricity generators.
|Home fuel cells (Jiji)
Leasing of Fuel Cells Begins
The fuel-cell system developed by Tokyo Gas Co. and Matsushita Electric Industrial Co. consists of a reformer that extracts hydrogen from methane, a fuel cell, a heat recovery device that heats water, and a tank for storing 200 liters of hot water. Under this system, hydrogen extracted from the natural gas (methane) supplied by Tokyo Gas to its customers and oxygen extracted from the air is used to generate 1 kilowatt of electricity through the reverse chemical reaction to that involved in the electrolysis of water. The heat released in the reaction is used to warm the water up to about 60 degrees Celsius. This system would supply about 60% of the electricity consumed by a family of four living in a house with 150 square meters of floor space, as well as providing hot water for things like bathing, washing up, and under-floor heating.
The system developed by Nippon Oil Corp., meanwhile, uses hydrogen extracted from liquefied petroleum gas (LPG). Other than having a slightly smaller electricity output of 750 Watts, it is almost the same as the one produced by Tokyo Gas.
Although neither system produces carbon dioxide when actually generating electricity, the gas is produced when extracting hydrogen by this method. However, as generating electricity and heating water simultaneously through cogeneration greatly increases overall energy efficiency, the overall effect of the system is to reduce carbon dioxide emissions.
As fuel cells for household use cannot store electricity, they generate only the amount that is being used at the time. The hot water produced as the electricity is generated is stored in the tank until it is needed to, for example, fill the bath. If there is not enough hot water when bath time comes around, extra water is heated automatically by an auxiliary heater.
According to Tokyo Gas, when electricity is generated by thermal power plants, the release of heat during generation and losses incurred when delivering the electricity mean that only 37% of the available energy is actually used. By contrast, the fuel-cell system uses 31% of the energy contained in natural gas to generate electricity and 40% to heat water, adding up to a total energy efficiency of 71%. The firm's calculations also show that using the system on full power results in a 40% reduction in carbon dioxide emissions and a 26% reduction in energy consumption compared with the combination of a conventional water heater and thermal power generation.
The system is also economical. It would save an average household ¥30,000 ($286 at ¥105 to the dollar) in electricity bills and a further ¥30,000 in gas bills each year. The Tokyo Gas team is offering its fuel-cell systems to owners of new houses for ¥1 million ($9,524), including maintenance costs for 10 years. It plans to sell 200 of the systems in the Tokyo metropolitan area by March 2006 but has much bigger ambitions for the future. By 2008 it intends to bring the price of the systems down to around ¥500,000 ($4,762) and to commence mass production. It eventually hopes to market the systems for condominiums, as well as houses.
As Nippon Oil Corp.'s system generates slightly less electricity, it is also somewhat less expensive. Costing ¥60,000 ($571) to lease for one year, it is expected to yield ¥60,000 in annual utility-bill savings. The company plans to sell 150 of these systems in the Kanto region and surrounding areas in the first year, before marketing them nationwide in 2006.
With consumers increasingly looking for products that help to protect the environment, as well as offering value for money, the market for household fuel cells is sure to grow in the years ahead.
Related Web Sites
Kanto in Region & Cities
Copyright (c) 2005 Web Japan. Edited by Japan Echo Inc. based on domestic Japanese news sources. Articles presented here are offered for reference purposes and do not necessarily represent the policy or views of the Japanese Government.
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ENERGY OF THE FUTURE
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