The Straits Times / The Business Times News on Hyflux

Water from the sea at cheapest rate

THE new Tuas plant is producing some of the cheapest desalinated water in the world. And prices are unlikely to change over the next three years.

One of the largest of its kind, the plant was officially opened by Prime Minister Lee Hsien Loong last night. It can produce up to 136,000 cubic metres of water a day, enough to fill 55 Olympic-size swimming pools.

International rates for desalinated water hover around US$1 (S$1.68) per cubic metre but the Tuas plant, built by Hyflux subsidiary SingSpring, is selling the water to the Public Utilities Board at 78 cents.

Hyflux chief executive Olivia Lum told The Straits Times last night that though the contract stipulates the rate must remain constant for a year, she estimates that price rises will not be necessary for at least three years.

This is surprising, given that desalination is a fairly energy-intensive process and fuel prices have been soaring of late.

'We had factored in major rises in the price of fuel over the next three years when we decided on the 78 cent price,' said Ms Lum. 'And that's unlikely to change.'

Hyflux 'hedged' the price of energy - financial parlance for a kind of insurance - when it won the bid to build the plant, said Ms Lum.

Indeed, one of the biggest advantages of the plant is its affordability.

Rather than conventional desalination methods, which use heat to distil seawater, the plant uses a technology known as reverse osmosis, or RO, where fine membranes are used to extract the salt.

'RO has always been far less energy-intensive than thermal distillation, but our plant is one of the cheapest RO plants available,' Ms Lum said.

Its cost-effectiveness is partly a product of its size and partly a result of its innovative use of energy-saving devices, said Ms Lum.

Higher-efficiency pumps and energy-recovery devices are helping save up to 50 per cent of the plant's energy costs.

A representative from Australia's Water Corporation, the government agency which looks after the country's water needs, told The Straits Times last night that Australia's biggest desalination plant will be offering desalinated water at A$1.16 (S$1.50) per cubic metre.

The Australian plant is of the same capacity as the one in Tuas. Being built in Perth, it will start operating late next year.

Mr Gary Crisp, the agency's principal engineer, said nature is also working in Singapore's favour to keep costs down.

Environmental factors such as water temperature and salt content are major determinants of how much energy a desalination plant needs to use, said Mr Crisp.

The colder and saltier the water, the more energy is required.

Membranes, for instance, do not function as efficiently in colder temperatures.

'The water around Singapore is far less salty than in Australia, and temperatures are much warmer,' said Mr Crisp.

'Both these factors could have been critical in keeping plant costs here low.'

radhab@sph.com.sg