BEIJING, JULY 30-- A new air conditioning system that makes ice overnight using cheap-rate electricity may be key to cutting strain on China's creaking power grid.
The unit, to go on trial in Guangzhou, Guandong Province, uses ice it makes during the night to cool the air during the day.
Called an Ice Storage Air Conditioner (ISAC), the device will be introduced throughout the province next year if it performs as well in Guangzhou as it has elsewhere.
The office building of the provincial Economic and Trade Commission will serve as a test site for the air conditioner, according to Chen Jian, director of the commission's energy department.
Guangzhou-based Zhuoyue Energy Co Ltd is now working to refurbish and add an ice storage unit to two central air conditioners.
The basic concept of ISAC is an air-conditioning unit that makes ice during off-peak hours, when electricity costs only 27.8 per cent of the rate charged during the day.
During the day, instead of using a power-hungry 5-kilowatt compressor, the unit pumps air cooled by the ice using a motor that needs only about 2 per cent of the electricity the compressor would use.
Compared with a traditional air conditioner, electricity consumption could be cut by as much as 90 per cent, Chen said.
He estimated that using this system in the commission's building could cut their yearly electricity bill by about 290,000 yuan (US$35,758).
"If the experiment goes smoothly, almost all office buildings and superstores will implement this new energy-saving device from next year," Chen said.
"Technology used in the new device has developed very well, and a proper off-peak electricity price is key for encouraging more buildings and superstores to implement the ice-making air conditioner."
Eight official buildings and superstores in Shenzhen, a coastal city in Guangdong, have been using the new air conditioner at the 20 per cent off-peak rate.
The Shenzhen Electronic and Science and Technology Building began using ISAC in May 2001.
"We have benefited from the ice-making air conditioner since its implementation, with more than 1.6 million yuan (US$197,280) saved annually through reduced electricity consumption," said Sun Mingguo, director of the building's property management office.
Chen said one of the other potential benefits of ISAC, if enough buildings use it, is that it would reduce the need to build more power plants.
According to figures provided by the commission, air conditioners in Guangdong currently use 10 million kwh each day, representing more than 35 per cent of total electricity usage.
ISAC has also been implemented in Southwest China's Chongqing Municipality.
(Source: China Daily)