The popularity of co-generation systems is increasing in Japan, with different types of home based Micro Combined Heat & Power (MCHP) systems being sold or expected on the market soon.TOKYO, Japan, JP, 2001-12-21 [SolarAccess.com] “There is strong demand for saving energy, and we believe there is high potential for cogeneration to spread into households,” says Yoshitaka Kayahara of residential cogen development with Osaka Gas. “Considering the need to reduce the amount of carbon dioxide emissions to prevent the greenhouse effect from escalating, there is a necessity to introduce cogeneration.” In October, the company began testing the market for home-use cogeneration systems by adopting Honda Motor’s 1 kW gas engine. The system can provide most of the heat, as well as 40 percent of total electricity needed by an average household. The system can save 30,000 to 40,000 yen a year in lighting and heating costs. After testing the new system at 100 homes, the company will sell the compact generator for 700,000 yen. IBF of Tokyo, has introduced a residential cogeneration system that uses a Stirling engine, operating on external combustion which runs pistons powered by contained, heated gas. The Stirling engine is manufactured by Whisper Tech of New Zealand, and provides an advantage over internal-combustion engines because it can use any type of fuel to heat the gas in the cylinder, even sunlight. “Because it can use anything as the fuel to run the system, we think Stirling engine cogeneration has huge potential,” say officials. The system, which can generate 0.75 kW, went on sale this year for 3.5 million yen and IBF has sold 14 units to homes and dormitories in ten months. The WhisperGen system has been sized to meet the heating requirements of a typical home in western Europe, and to match the electrical generation with the home’s requirements, to keep power available for export to the grid to a minimum level. If the utility refuses to accept the distributed generation for any reason, or will not pay an acceptable price, the unit can be used in the home for heating water via an immersion heater. Currently, the AC WhisperGen is designed to continually monitor for the presence of the grid. If the grid drops out of certain ranges in voltage or frequency, the system automatically shuts down to ensure that it does not export into a failed grid. Most Japanese companies developing home-use cogen systems are focusing on natural gas fuel cells. Home appliance makers, including Matsushita, Toshiba, Sanyo and Toyota, are developing fuel-cell cogen systems for residential applications, and many expect to have 1 kW systems by 2004 or 2005. Osaka Gas is developing a fuel-cell cogen system, and Kayahara says gas cogen systems provide more heat than electricity, while fuel-cell cogen systems provide the opposite; more electricity than heat. “We believe that there will be demands for both gas and fuel-cell engines, because the use of energy will vary depending on customers’ lifestyles, as well as where they live,” he says. Osaka Gas aims to release its residential fuel-cell cogen system in 2005, at a price of 600,000 yen. The companies are trying to reduce initial costs of systems but they share a belief that, once residential cogeneration systems become accepted, mass production will allow costs to drop.