The energy company officially opened the $20 million plant at its Jurong Island facility yesterday.

Managing director Neil McGregor said the plant consumes 30 per cent less electricity than conventional desalination plants.

When the plant runs at full capacity, about 10,000 cubic m of water, enough to fill four Olympic-size pools, can be produced per day.

Ninety per cent of the water will be used to clean floors, flush toilets and the like. The rest is clean enough to drink.

The drinking water has not been licensed for sale by regulators, but the firm may get the rights to sell it to water barges.

Senior Parliamentary Secretary for the Ministry of the Environment and Water Resources Amy Khor opened the plant. When asked if the supply of water could be deregulated, Dr Khor said the idea, while a good one, was not currently being considered.