BUZZ contributor and Safety Engineer Sam Fan explains to BUZZ readers that extreme heat drives electricity use to shorten wiring lifespans and, in buildings over 30 years old, poses power cut and fire risks.
To raise awareness of electricity safety among non-Chinese-literate residents in Sai Kung, I have translated the following Ming Pao article into English for their information. I have also witnessed a few power outages in the older residential buildings in Sai Kung town. Moreover, although electrical installations inside residential and commercial premises (e.g., eateries, shops, offices) with an approved loading of not more than 100 amperes are not subject to mandatory periodic inspection, testing, and certification (PITC), such building owners are still strongly advised to employ a registered electrical contractor to inspect their electrical installations for the sake of their own safety. Common safety issues with these smaller electrical installations include a faulty or missing residual current device, missing earthing conductors, undersized cables, wiring errors, and a lack of surge protection for installations fed from overhead lines, which are not evident to non-electrical engineers.
Original Article from Ming Pao, 16 August 2026 https://news.mingpao.com/p1786814294450
Hong Kong has recently experienced prolonged high temperatures alongside frequent power incidents. According to electrical and mechanical engineering sector representatives, hot weather compromises power system stability as electricity supply and load capacities approach saturation, while high ambient temperatures accelerate cable deterioration. The industry noted that Hong Kong contains many buildings over 30 years old. While the electrical wiring originally installed in these properties has a “theoretical lifespan” of 30 to 50 years, prolonged overloading during extreme heat can reduce its actual lifespan to around 30 years, heightening the risk of frequent power failures and electrical fires. (Reported by Ming Pao reporter Fong Ning)
The territory recently saw consecutive days of extreme heat, with Sheung Shui recording a record high of over 39°C. At the same time, areas such as Shui Pin Wai Estate in Yuen Long and Riviera Gardens in Tsuen Wan experienced power failures of varying severity. On the link between high temperatures and power outages, Cheung Wing-ho, Chairman of the Federation of Hong Kong Electrical & Mechanical Industries Trade Unions, told Ming Pao that increased air-conditioning use in hot weather drives up electricity consumption, pushing supply and load levels close to saturation. Furthermore, aluminium and copper wiring experiences higher electrical resistance as temperatures rise, causing greater power loss. Because electrical conduction generates heat, a vicious cycle ensues, accelerating the ageing of electrical equipment and shortening its operating life.
Electrical and mechanical industry representatives note that during hot weather, power supply and load capacities approach saturation, accelerating cable wear and leading to frequent power supply incidents. Pictured is Tsuen Wan Centre in June this year, where a burnt-out transformer caused a power cut and water outage. That evening, some residents had to navigate the stairs in the dark to return home, while others stayed in hotels overnight. Photo: Ming Pao File Photo
Theoretical Wiring Lifespan of 30 to 50 Years
Cheung explained that although the theoretical lifespan of electrical cables is 30 to 50 years, their actual longevity depends on ambient temperatures and power consumption. Power distribution systems in older buildings were not originally designed with sufficient electrical load capacity. Coupled with the increasing frequency of extreme heat, cables face long-term overloading. Consequently, wiring in some buildings aged 30 to 50 years suffers from severe ageing, reducing its effective lifespan and potentially triggering power cuts or fires during extreme heatwaves.
CLP Reports Consumption Rise; HK Electric Notes Similar Demand
In response to enquiries, China Light & Power (CLP) stated that under recent sustained high temperatures, electricity demand rose compared to the same period last year. Hongkong Electric replied that the extreme heat had not affected its power supply, with customer consumption patterns remaining similar to the same period in previous years.
Calls for Subsidies to Replace Power Systems in Older Buildings
Cheung said wiring in some older buildings has reached a critical tipping point and needs renewal. However, as many owners of older buildings belong to low- to middle-income groups, they may be unable to afford maintenance costs. He suggested that the government model a scheme on the “Lift Modernisation Subsidy Scheme” to subsidise eligible owners or incorporated owners’ corporations in upgrading their power systems.
Legislative Councillor for the Engineering Constituency, Ir Aaron Bok, told Ming Pao that although electricity usage increases during hot weather, power systems will trip automatically to disconnect the electricity supply and prevent fires, provided their overload protection devices function correctly. He emphasised that under the Electricity Ordinance, fixed electrical installations in buildings must undergo periodic testing every five years, including cable testing and protection device operational checks, conducted by registered electrical contractors and registered electrical workers. Any non-compliant or aged installations identified during testing must be replaced. Aaron Bok added that fixed electrical installations in private buildings belong to the respective property owners, who should arrange upgrades as early as possible if inspections reveal ageing. He recommended that all building owners conduct regular checks on various facilities—such as maintaining building lifts and water drainage systems—to ensure proper operation.
References
Original Article from Ming Pao, 16 August 2026 https://news.mingpao.com/p1786814294450
New Edition of the Code of Practice for the Electricity (Wiring) Regulations, Electrical and Mechanical Services Department https://www.emsd.gov.hk/en/electricity_safety/new_edition_cop/new_edition_cop_electricity_wiring_regulations/index.html
Electricity Safety Publications, Electrical and Mechanical Services Department https://www.emsd.gov.hk/en/electricity_safety/publications/general/index.html#hes
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