MEASURES TO SAFEGUARD AGAINST MASSIVE BLACKOUT

Mr S Iswaran asked the Minister for Trade and Industry what measures already exist, and what additional measures are needed, to safeguard against the occurrence of a massive blackout like that which recently affected Auckland, New Zealand.

The Senior Parliamentary Secretary to the Minister for Trade and Industry (Mr Tang Guan Seng) (for the Minister for Trade and Industry): The cause of the recent cable failures in Auckland, New Zealand, has yet to be established. According to some reports, they were probably caused by the abnormal drying up of the soil surrounding the cables due to the prolonged hot and dry summer. Consequently, heat could not be conducted away from the heavily loaded cables fast enough. The cable temperature could have risen well above its design specifications, leading to the cascading cable failures.

Such form of cable failure is unlikely in Singapore as PowerGrid Ltd, the electricity network operator in Singapore, has instituted the following measures:

(a) Firstly, PowerGrid has built a strong transmission network. For example, the CBD network is supplied by multiple 230 kV sources and is interconnected to provide contingencies to take care of unforeseen cable failures or damages.

(b) Secondly, PowerGrid's 230 kV transmission cables are installed with backfill designed to ensure efficient heat dissipation and avoid thermal overloading.

(c) Thirdly, with advances in technology, Distributed Temperature Sensing (DTS) cables are now available which enable real-time monitoring of the actual cable temperature. PowerGrid has installed such DTS cable on a 400 kV cable and will be installing it on two additional 400 kV cables and future 230 kV cables.

PowerGrid has a rolling 10-year development plan to expand and renew the network to meet Singapore's electricity demand in a reliable, secure and timely manner. For example, PowerGrid is currently developing a new 230 kV substation at Peng Nguan Street to reinforce the network in anticipation of the CBD's rising demand in the years to come.