9:00 p.m. (g)
One big advantage is economy of scale: it is cheaper to chill a lot of water for many buildings than for each building to chill a little of its own. A district cooling plant saves money by chilling water at night when electricity is cheaper, storing the water in tanks.
Singapore is a late convert to district cooling. After dismissing it in the 1970's as a waste of land, planners rediscovered the idea in the mid-90's while studying Yokohama, Japan, for ways to develop the growing downtown area. Like Singapore, Yokohama had expanded onto reclaimed land and used common service tunnels. But it had also adopted district cooling.
There was one problem, the Urban Redevelopment Authority learned. ''It's not a very profitable business'' if consumers have alternative sources of supply, said Lim Teck Leong, the authority's executive civil engineer. Persuading Singapore's monopoly utility at the time, Singapore Power, to invest in it would require a big incentive: a guaranteed market.
While it was studying what to do, two smaller district cooling plants opened in Singapore, both in areas where the property owners also owned the plant.
IN March 2001, Singapore established the Energy Market Authority and gave it the power to mandate the use of district cooling. The new authority promptly decreed that developments in the first 74 acres of the 890-acre Marina South area would have to buy district cooling.
''In other countries, developers would probably object,'' said Shahzad Nasim, managing director at Meinhardt. In Singapore, they have no choice.
The redevelopment authority sold the first parcel of land in Marina South, 2.8 acres, for $257 million to a joint venture between a local developer and two Hong Kong partners. Robert Garman, the venture's general manager, says his company is happy to have the cooling plant in the twin towers it is building. ''We're looking forward to a savings,'' he said.
Between the two buildings, on top of a shopping mall, Singapore Power will spend roughly $56 million to construct towers to chill water to 43 degrees and store it in tanks in an underground parking garage.
Developers expecting a windfall, however, may be in for a surprise. Until it has recouped its investment, Singapore Power plans to charge them roughly the same amount it would cost to power their own air-conditioners, said Tey Peng Kee, managing director of Singapore Power's district cooling division. Only then will rates go down.
Still, officials here hope that district cooling will eventually sell itself. ''After it gains acceptance by developers, said Mr. Yeo of the Energy Market Authority, ''it may not need to be made a mandatory requirement.''
Correction: June 9, 2002
An article last Sunday about Singapore's plan for enforced central air-conditioning in a new downtown area misidentified the British law school attended by Lee Kuan Yew, the first prime minister of Singapore, who once called the air-conditioner the most important invention of the 20th century. It was Cambridge, not Oxford.
