The Environment Ministry plans to introduce an experimental program to use a geothermal heat pump system for public facilities as part of Japan’s efforts to curb global warming, ministry officials said Monday.

The officials said the program, to begin in fiscal 2003, will involve using power-saving geothermal heat pumps for hot water and air conditioning at public facilities, including hospitals, libraries and city halls in 60 locations across the nation.

The system makes use of geothermal heat that is 20 to 100 meters below ground and has stable year-round temperatures of 10 to 15 degrees. The ministry estimates that using geothermal heat pumps for air conditioning, for example, would result in an energy saving of 40 percent.

Because the pipes — about 10 cm in diameter — that carry the heat to the surface will be completely enclosed, the system will have no effect on groundwater.

Two-thirds of the cost of construction, estimated at 10 million yen for each installation, will be shouldered by the government and local authorities.

According to the officials, expenses in the initial period will be high, but the operational costs are manageable, with hardly any maintenance expenses, and the project is expected to pay off in about 10 years.

It is hoped that the system will bring geothermal heat pumps to households in the future, they said.

In the United States and Europe, use of geothermal heat is fairly widespread and has increased notably over the past five years, the officials said. In Japan, there are currently only 40 facilities for utilization of geothermal heat.

Domestic geothermal heat pump systems have been developed by the New Energy and Industrial Technology Development Organization, an affiliate of the Ministry of Economy, Trade and Industry.

Geothermal heat pumps use the ground as a heat sink in summer and a heat source in winter, transferring heat from the warmer ground to the building in colder months, and taking heat from the building in warmer times and discharging it into the cooler ground.

Besides saving energy, the pumps address the “heat island” phenomenon of excessive warming of urban areas, the ministry said.

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