Prevention of Power Outage in Central Business District

15 Ms Joan Pereira asked the Minister for Trade and Industry with regard to the power outage in the CBD area on 1 June 2018 (a) what is being done to prevent future occurrences; and (b) what backup systems are in place for essential services like traffic signalling systems and medical services.

Mr Chan Chun Sing: The Government recognises the importance of a reliable and secure power system. SP Power Grid (SPPG), the national grid operator, has a comprehensive infrastructure planning and maintenance regime to increase system reliability and minimise disruptions. This includes building in redundancy for critical components, continuous monitoring of the transmission network, and conducting preventive maintenance. We have adopted a calibrated risk-based approach in systems planning, with a framework in place to enable quick restoration of power when needed. So far, this approach has served us well, with our power system being among the most reliable in the world. For instance, from financial year (FY) 2013 to FY2017, Singapore's average annual disruption per consumer ranged from 12 seconds to 45 seconds, compared to latest FY2015 figures of four minutes for Tokyo and 23.4 minutes for Hong Kong.

Our investigations show that the blackout in the Central Business District (CBD) on 1 June 2018 had occurred due to human error on the part of SPPG and its contractor while carrying out maintenance work at a substation at Ann Siang Hill. Nonetheless, SPPG was able to progressively restore supply to all affected consumers within 34 minutes, which included conducting the necessary tests to identify and rectify the cause of tripping.

SPPG has since tightened its maintenance and training protocols to prevent similar incidents in the future. It has also reminded its officers of the need to adhere strictly to standing operating procedures, and instituted additional checks for similar maintenance works. For example, SPPG will be introducing mandatory video recording of maintenance work, which would be reviewed by senior officers before the equipment can be switched on after maintenance works are completed.

The Energy Market Authority (EMA) treats each blackout incident seriously and will thoroughly investigate each incident and take appropriate regulatory action, such as imposing financial penalties, against the relevant parties. Under its existing contractor performance management system, SPPG can also impose strong disciplinary actions, such as immediate suspension of errant contractors. EMA will continue to work closely with SPPG to ensure high standards of reliability for our power system.

Essential services, such as traffic signalling systems and public hospitals, have contingency plans to ensure that they are not affected by power outages on the national grid. For instance, Singapore’s road systems are monitored round the clock. In the event of any power outage affecting traffic signals, the Land Transport Authority will work with the Traffic Police to quickly deploy resources, where needed, to assist with traffic control at affected junctions. Concurrently, backup generators can also be deployed onsite to provide temporary power supply to mitigate the impact to traffic signal operations.

For public hospitals, they are provided with dual supply sources, each of which is able to take the full load of the hospital if the other one fails. If there is any disruption from the main power source, backup power systems, such as diesel generators and Uninterrupted Power Supplies (UPS) systems, would automatically kick in, to support all critical equipment and critical facilities. Hospitals also carry out regular and preventive maintenance to ensure that both their electrical installations and backup power systems are in good working condition.