A major power outage hit pockets of the financial capital on Sunday, halting the city lifeline local trains for over an hour and inconveniencing residents on a weekend.
Taking serious note of the power disruption in Mumbai, a rare occurrence, the Maharashtra government has ordered a high-level probe.
The state-run Maharashtra State Electricity Transmission Company and the private sector Tata Power blamed each other for the outage which lasted for over an hour in the morning hours.
The power supply was fully restored from around 11 am, starting with emergency services like the railways.
Services on the Western Railway between Andheri and Churchgate stations stopped for over an hour starting 0950 hrs, Central Railway's Harbour line experienced a brief stopping of services and the heritage Chhatrapati Shivaji Terminus station saw an outage of electricity supply.
An MSETCL statement attributed the outage -- which comes almost 17 months after a massive outage in October 2020 -- to a technical fault triggered after a series of events, while the private producer Tata Power blamed it on the transco.
MSETCL said some lines were shut due to the metro building works while the alternatives also faced a technical fault leading to the outage.
At 0844 hours, there was a technical fault on the Trombay-Mulund transmission line, leading to a surge in demand, the statement said, adding that Tata Power was requested for additional supply from its thermal and hydel units.
“However, the Tata group company insisted on an email to start the supply from its units. If the company had provided the power, we could have avoided the incident,” alleged MSETCL.
Tata Power's president for transmission and distribution Sanjay Banga countered MSETCL saying, “our initial investigation is that this disturbance in our grid was because of the tripping of MSETCL lines.”
There are four circuits at MSETCL which supply power to the Trombay receiving stations of Tata Power, he said, specifying that two circuits were already under maintenance, the third circuit tripped at 8:40 hrs, and the last circuit at 9:50 hrs.
“When it tripped, it created a disturbance in our Tata Power system. There was a reduction in demand to the tune of 850 MW. The total demand of Mumbai came down from 2000 MW to around 1200 MW and different parts of Mumbai were affected like South Mumbai, Chembur, and suburban areas,” he said.
Banga said the company restored the power supply in an hour by stepping up hydro generation to full capacity and avoided much larger damage.
Maharashtra Energy Minister Nitin Raut said he has ordered a high-level inquiry into the 70-minute power outage incident in South Mumbai, as per a statement from his office.
"I instructed the officials to ensure restoration of the power supply at the earliest and also took stock of the work in progress at regular intervals. The power supply was restored in 70 minutes. The government has taken serious note of the incident and a high-level probe has been ordered. Those found guilty will be punished," the power minister said.
People enjoying the day-offs at their residences in central and south Mumbai, and also some in the western suburbs faced inconveniences, while the timing of the outage of services aggravated the woes for those who had advanced their travels due to the scheduled maintenance works on railway tracks on Sunday.
In a statement, Adani Energy Mumbai said the power supply was caused due to the tripping of the 220 kv transmission line and the subsequent outage at Tata's Trombay Power plant.
The company ramped up generation at its plant in Dahanu and its consumers are “largely unaffected”.
Tata Power's Banga said a detailed investigation of this outage is on and it is coordinating with all agencies, including SLDC (state load despatch centre), to find out the exact reason.
It can be noted that the exact cause of the power outage in October 2020 - which had taken up to 18 hours to restore fully - is still unknown, even though some officials had called it sabotage by blaming it on a cyberattack.
Power outages are rare in Mumbai and its satellite towns with power grids designed to supply electricity 24 hours.
