Green buildings: Bright ideas to cut power use

Elizabeth Wilmot, Straits Times 11 Sep 08;

A COMBINATION of energy-saving factors to slash consumption and a cutting- edge solar technology called photovoltaics can add up to what every boss wants - a zero-energy building.

Zero energy means the building is sustained with renewable sources of power, which saves hugely on costs over the long term.

It is a Holy Grail but highly achievable, said Mr Poul Kristensen, managing director of IEN Consultants, a Kuala Lumpur-based company that advises clients on green buildings.

He told the Institute of Southeast Asian Studies yesterday about office buildings in Malaysia that would typically consume about 200 to 300kw of energy per square metre a year.

That can be cut to about 100kw by using energy-saving measures such as daylighting, which uses tubes and reflectors to illuminate a room using natural light.

Energy-efficient server rooms, lighting, office equipment and proper insulation to prevent unnecessary heat loss and wastage can also cut power use.

With the reduced consumption, the building can then rely on solar panels integrated in the roof and walls to provide the rest of the needed energy.

The PTM Zero Energy Office of the Malaysia Energy Centre in Selangor is one example of a building aiming at zero energy consumption.

It has already reduced energy use to 35 to 40kw per sq m a year and is still fine-tuning its systems.

Zero-energy buildings have been developed in Canada, the United States, Germany and Switzerland.

Singapore's Building and Construction Authority is also aiming to turn an existing block of its academy into one powered by solar panels.

The task comes with challenges. Constructing an energy-efficient building can increase costs by up to 21 per cent. The figure jumps to 45 per cent if photovoltaics technology is included.

'It might be more expensive at first, but after the payback time, which is

between five and 10 years, the cost savings are for a lifetime,' said Mr Kristensen.