Hong Kong’s largest electricity supplier pledges to ensure stable supply of power after 3 voltage dips
- Three voltage dips this year left more than 200 residents trapped in lifts, with CLP Power saying bad weather played role in most of interruptions
- But company stops short of saying whether it will follow lawmakers’ calls to install devices to mitigate power interruptions in buildings free of charge and adopt penalty system
Hong Kong’s largest electricity supplier has pledged to strengthen measures to ensure the stable supply of power after three voltage dips this year left more than 200 residents trapped in lifts, with the utility saying bad weather played a role in most of the interruptions.
But CLP Power stopped short of saying whether it would follow lawmakers’ calls to install devices to mitigate power interruptions in old buildings free of charge and adopt a penalty system for when people became trapped in lifts due to voltage dips.
CLP has logged three voltage dips so far this year, after recording nine last year.
Michael Lau Ho-yin, the firm’s director of power systems, said on Thursday that 80 per cent of incidents tied to voltage dips were caused by external factors such as typhoons, lightning strikes or interfering objects such as drones, balloons or construction machinery.
“More than 30 per cent of our power supply system consists of outdoor overhead cables, which are prone to voltage dips caused by typhoons, lightning strikes or interference from external objects,” Lau said. “Underground cables are also at risk of voltage dips due to third-party excavation projects causing damage.”
He said CLP Power, which serves Kowloon, the New Territories and most outlying islands, had adopted various measures such as installing lightning arresters, clipping trees and conducting inspections of third-party projects to mitigate the impact on cables.
Lau added the firm had set up a maintenance team to monitor and trim 170,000 trees near power supplies.
A high-voltage-equipment failure at Black Point Power Station in Tuen Mun caused a voltage dip last month and left at least 152 people stranded in lifts and set off 16 fire alarms in Kowloon and the New Territories.
A week earlier there were 52 reports of people stuck in lifts, with a preliminary investigation suggesting a hill fire in Yuen Long’s Shap Pat Heung had affected overhead lines on pylons, causing a voltage dip.
In January, authorities gave the firm a month to inspect its electricity supply system after two incidents a week apart resulted in 20 reports of people trapped in lifts.
Lau said power dips typically lasted for 0.1 seconds without causing power outages, but sensitive devices such as lifts and escalators might temporarily stop operating after triggering the protection system and require qualified engineers to restart.
Affected lifts equipped with voltage dip mitigation devices could resume operation after self-inspection, he said.
Hong Kong has nearly 70,000 lifts, and regulations mandate those installed after 2009 must have devices to manage voltage drops.
Lawmaker Michael Tien Puk-sun earlier called for imposing HK$10,000 fines for each instance of people trapped in lifts caused by voltage dips, with each affected individual receiving HK$1,000.
Legislator Edward Lau Kwok-fan also suggested that authorities and energy companies assist in installing voltage dip mitigation devices in older buildings to prevent lift entrapment.
CLP Power’s Lau did not comment on these suggestions, only saying that a dedicated team had been put in place to offer free consultations for customers who wanted to install mitigation devices for lifts.
He said more than 100 customers had approached the team and about half of them had adopted suggestions in the past three years.
CLP Power is due to report the incidents to the Legislative Council’s environmental affairs panel on May 27.
