Large swathes of the city suffered a massive blackout Wednesday morning, affecting about 42 percent of CEM’s clients.
The outage lasted about one and a half hours. Following the blackout at about 11 a.m., the power utility began to gradually restore power to the city after about an hour.
A malfunction in the 110kV high-voltage circuit breakers in the Canal dos Patos substation subsequently affected the S. Paulo, Dona Maria, Outer Harbour and Areia Preta substations.
The massive power cut affected the northern and central districts of the peninsula and the Henquin campus of the University of Macau (UM), while some areas of Taipa and Coloane experienced dips in voltage.
According to a CEM statement, the outage affected around 100,000 customers. The utility has about 240,000 customers, according to a spokesperson. This means that about 42 percent of CEM’s clients were affected by the power cut.
The public Conde de S. Januario Hospital Centre was not affected and was able to continue working during the outage thanks to its own generators.
All of the city’s public health centres have back-up generators so were without power just for a matter of seconds. No patients were affected.
According to information by the Traffic Bureau (DSAT), 71 traffic lights were not functioning during the outage. All were working again by the afternoon.
The Guia Hill cable cars stopped for about 10 minutes during the outage. Several people were trapped in the cabins between the hill and lower station during the stoppage.
After the outage, which hit at 10:56 a.m., the Energy Sector Development Office (GDSE) called an emergency press conference in conjunction with other entities at noon Tuesday.
Addressing the press conference, senior Fire Service (CB) officer Lam Io Fan said the service had received 75 calls from people stuck in lifts, and four of them had to be taken to the hospital because they were feeling unwell.
Senior Public Security Police (PSP) officer Un Kim Fong said the police had deployed extra patrols in the affected areas to maintain order. He also said that all border checkpoints were working as usual during the power cut. No increase in crime was reported.
Un said the PSP’s emergency service call centre was temporarily paralysed as many people attempted to call for help at the same time.
CEM Executive Committee Chairman Bernie Leong Wa Kun reassured reporters that his company has measures in place to ensure that vital facilities, such as hospitals, will not be affected by a power outage such as Tuesdays.
When asked about the black smoke belching from the Coloane power plant Tuesday, Leong explained that from a technical perspective, it was normal and there was no need to worry. CEM used some of its generators in Coloane as a backup during the power cut.
GDSE Director Arnaldo Santos requested CEM to submit a preliminary report on the incident in a week, and a full report within a month.
CEM invited the press to visit the malfunctioning substation Tuesday afternoon. CEM Network Operations and Maintenance Department Senior Manager Billy Chan Hon Keong said that the power cut was caused by a short circuit in the high voltage switches, but due to the gas released by the high voltage circuit breaker, which he said was a standard safety mechanism to avoid damaging the components as the temperature rises, the maintenance team was unable to enter the building until 5 p.m.
Chan described the outage as “quite severe”, but added that it was “very rare” for the high voltage circuit to malfunction.
Chan said that the utility performs monthly checks on the equipment’s gas pressure, and a full inspection every year.
Chan said that the Siemens equipment was installed in 2008. He stressed that it was built to last 30 or more years.
When asked whether CEM would rely less on the mainland’s power supply, Chan said that as the fault of Tuesday’s outage was in Macau, there were no plans to change the power supply arrangement with the mainland. However, he also said that CEM would look into restructuring its maintenance plans to ensure that such an incident would not happen again.
Both apologised for Tuesday’s incident. Chan said the utility would pay possible damages in accordance with its contractual obligations. (macaunews/macaupost)