Tokyo Sky Tree to save energy through water circulation+

TOKYO, June 20 Kyodo -
The 634-meter Tokyo Sky Tree communications tower under construction in Sumida Ward will be equipped with an eco-friendly heating and cooling system that circulates cold and hot water reserved underground.
The operating body, Tobu Railway Co., and its subsidiary Tobu Energy Management Co. on Thursday unveiled one of the four huge water tanks around 20 meters underground capable of storing 7,000 tons of water combined, equivalent to water in 17 25-meter swimming pools.
By utilizing the power generated at nighttime when demand for electricity is not high, the system will keep water temperatures at 5C during summer and 48C in winter by operating heat pumps and refrigerating machines.
The operator expects to save 40 to 50 percent in electricity consumption at peak times during the summer and winter by circulating the stored water to cool and heat related facilities.
Water in the storage tanks could also be used for firefighting as well as for daily activities under emergency circumstances.
The world's tallest self-standing tower is scheduled to open for visitors on May 22 next year.