S'pore has world's largest district cooling plant

SINGAPORE - All the action at what is arguably the world's largest district cooling plant by capacity is well hidden from public view. The plant is located five floors - about 25m - underground.

The only evidence of the plant's existence is a cleverly concealed cooling tower, which pops up above the ground facing Marina Bay Sands' hotel building.

A curtain of metal plates that allow exhaust heat to escape the tower shimmers in the sunlight, and a strategically placed water feature masks the sound of the water that flows from it.

Even access to the plant, which produces 600 tonnes of chilled water per hour, is like a scene out of Alice in Wonderland - there is no signage, only a small door located at the end of the Double Helix Bridge. Stairs and a lift transport the plant's 52 employees deeper underground.

Chilled water is one of several utilities continuously pumped through a network of common services tunnels to 14 customers in the area, including Marina Bay Sands, the Marina Bay Financial Centre and One Raffles Quay.

District cooling is an energy-efficient and cost-effective method to provide buildings in the area with an optimal indoor climate.

In the case of Singapore District Cooling, chilled water is produced by production plants and distributed by water pipes contained within the common services tunnels. Specially designed units within each building draw on the cooling properties of the water to, for instance, lower the temperature of the air passing through the air-conditioning system.

There are three interconnected plants in Marina Bay spanning a total of about 19,000 sq m - the other two plants are at One Raffles Quay and One Marina Boulevard - and there are plans to grow this to five plants, so more than eight million sq m can ultimately be serviced.

The success of a cooling plant lies in being able to maintain the temperature of continuous water flow at under 6 deg C.

At Singapore District Cooling, that standard is met 99.9999 per cent of the time.

Using a district cooling facility - as opposed to having to build and install their own plant rooms and cooling towers - helps make businesses in the area about 30 per cent more energy-efficient.

In temperate countries, similar networks can be used to supply heating, as is the case with Keppel's District Heating and Cooling Systems plant at the Sino-Singapore Tianjin Eco-City in China. Keppel also has three district cooling plants. They are located in Changi Business Park, Biopolis and Woodlands.

While it is more common in the United States and the Middle East, district cooling is catching on in Asia, said Singapore District Cooling managing director Jimmy Khoo, adding that the Marina South substation is a "true success story for Singapore".

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