POWER CONSERVATION

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POWER CONSERVATION: **

("No-jackets" rule for formal Government functions): **

22.

Mr Seah Kian Peng asked the Minister for the Environment and Water Resources in light of the extensive use of air-conditioning in Singapore, whether his Ministry will consider promoting a "no jackets" rule for formal Government functions to save electricity.

Assoc. Prof. Dr Yaacob Ibrahim: We share Mr Seah's concerns about energy wastage.

Yet at the same time, we do not want to be overly prescriptive and impose rules on all formal Government functions. Instead, we will leave it to the respective organisers to exercise due discretion, and dress-down when it is appropriate.

However, as a nation we must address the larger question of how we can save electricity effectively. We must examine the root causes of high energy consumption and adopt cost-effective solutions to reduce excessive energy losses. There are three main causes of such losses relating to air-conditioning:

Firstly, energy wastage may be due to an inadequate building envelope. An adequate envelope will minimise heat gain into the building interior and prevent cold air from escaping. This correspondingly reduces the energy consumption from air-conditioning. Since 1979, a minimum standard for thermal performance of the envelope of non-residential air-conditioned buildings has been put in place by BCA, and revised in 2004. Earlier this year, a minimum standard for residential buildings was put in place as well.

Secondly, buildings may be over-cooled. Generally, this refers to setting the temperature for the central air-conditioning system of the building below the recommended comfort zone of 22.5 to 25.5 degrees Celsius. As a heuristic, lowering the indoor room temperature by 1 degree Celsius through air-conditioning can increase the electricity consumption of air-conditioning by about 3%.

To reduce over-cooling, buildings must be equipped with the proper control, monitoring and air-handling systems required for the uniform cooling of the building. Otherwise, parts of the building may be over-cooled, while other parts may be too warm. Thus, it is important that developers, building owners and designers put in place adequate systems when the buildings are constructed.

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Lastly, besides reducing the air-conditioning load to a minimum with an appropriate envelope, and reducing over-cooling by implementing adequate systems, we have to look into how the air-conditioning can be provided in the most efficient way, namely, by implementing an efficient chiller system. The chiller system, which comprises the chiller plant, pumps and cooling towers, may be poorly designed or implemented, resulting in low efficiency. The efficiency of chiller systems can be measured using an indicator called the coefficient of performance (COP). The COP of the chiller system for an average building in Singapore is estimated to be about 3.0. If best practices and commercially available technology are deployed, a COP of more than 4.7 can be achieved, with potential energy savings of 35% to 50%.

To help our private sector reduce their energy wastage from air-conditioning, the NEA is working with other relevant agencies, such as BCA, on a package of incentives and measures, aimed at building up the capability of our developers, engineers, architects and building managers in the area of building energy management. This will help improve the way air-conditioning systems are designed and operated in buildings.

The public sector is also taking the lead on energy efficiency. All large air-conditioned Government office buildings, as well as polytechnics and ITEs, will conduct energy audits to improve their energy efficiency by March 2010. As of end July 2008, 17 such Government buildings have completed their audits, with eight having already implemented the recommendations to achieve S$2.6 million in annual savings. All large public buildings are also to ensure that the ambient indoor air temperature is maintained within the range of 22.5 to 25.5 degrees Celsius, and agencies should seek to maintain temperatures as high as comfort level allows.

In addition, to ensure that the chiller systems in our large Government buildings perform efficiently, we will progressively require them to meet a minimum standard of 4.7 for COP. A few of our buildings are already able to meet this standard. For example, in 2007, the Environment Building increased the COP of its chiller system to 5.0, and realised actual savings of 464MWh of electricity, or S$78,000, in 2007. The MOM building is in the process of implementing the measures identified by their energy audit as well. They are expected to improve the COP of their chiller system from 3.2 to 5.2, with estimated annual savings of over 1,300MWh of electricity, or cost savings of S$339,000.