An unprecedented power outage brought Mumbai to a standstill on Monday, affected local trains, left several people trapped in lifts, and led to chaos on roads after signals went on a blink.
The outage affected the entire city and suburbs including neighbouring Thane, Navi Mumbai and other parts of Mumbai Metropolitan Region (MMR) leaving India’s financial capital paralysed for more than four hours. Maharashtra Chief Minister Uddhav Thackeray ordered a technical audit of the incident in the afternoon.
The misery of Mumbaikars began around 10.10 a.m. with the tripping at the Maharashtra State Electricity Transmission Company Limited’s (MahaTransco) Kalwa-Padgha centre. It affected lakhs of domestic consumers of the State government, Brihanmumbai Electric Supply and Transport, Adani Electricity Mumbai (AEML) and Tata Power.
Power Minister Nitin Raut said, circuit 1 of 400kV GIS centre at Kalwa-Padgha of MahaTransco was undergoing repair and maintenance and the load was on circuit 2. “Some technical problem in circuit 2 led to problems in power supply to Mumbai and Thane,” he said. The CM met Mr. Raut and private power companies in the afternoon and ordered a technical audit into the incident. “Technical faults need to be identified. Those who are responsible should be identified,” he said.
While civic authorities claimed that essential services, especially Covid care centres and hospitals too faced power outage, diesel generators were automatically put into use. Mumbai’s water supply was hit and is likely to stay affected on Tuesday.
The outage affected train services on the western, central and harbour lines. Commuters stuck on trains could be seen walking on the tracks. According to Central Railway officials, harbour line services were restored at 10.55 a.m. and central line on 12.26 p.m. “WR’s suburban train services were restored between Churchgate & Borivali at 12.20 hrs. Services were already on between Borivali & Virar,” a Western Railway official said.
CR also rescheduled five long-distance trains — two to Gorakhpur and one each to Darbhanga, Varanasi and Thiruvananthapuram.
It was a nightmare for some employees working in an upscale business complex in central Mumbai who found themselves stuck in an elevator during times of social distancing. They were evacuated after some time.
Mumbai and metropolitan areas get their power supply through Kalwa sub-station where four 400 kV lines join. In addition, Tata and Adani together supply 1800 MW power. On October 10, 400 kV Kalwa-Talegaon (Power grid) was closed due to a problem with its conductor. Restoration work is on, but there are delays since it is in a remote hilly area.
Early on Monday morning, at 4.33 a.m., the Kalwa-Padgha line-1 malfunctioned due to over voltage. The power supply to Mumbai was through the remaining two lines. However, the 400 kV Kalwa-Padgha line-2 too malfunctioned at 10.01 a.m., resulting in islanding, of Mumbai’s power supply, which was further affected as 500 MW Tata Power plant and 250 MW AEML’s Dahanu plant were closed. , said the state government.
An AEML spokesman said, “Due to transmission network failure outside of our system at 10.05 this morning, the power grid saw outages across utilities in Mumbai. However, the AEML distribution system operated islanding facility successfully and continued power supply to vital installations with the help of the Dahanu Thermal Power Station. We wish we had more power for which we are dependent on grid input. Power supply to remaining consumers is being restored in a phased manner.”
Tata Power, in its statement, said, “It is understood that MSETCL had taken emergency shutdown for 400 kV Kalwa-Padghe line-1 at 6.54 hrs this morning to attend fault and was expected to be revived by 09:30 hrs, but could not revive it. As understood, at 09:58 hrs 400 kV Kalwa-Padghe-2 carrying 633 MW tripped. The flow on Pune-Kharghar rose up to 900 MW and tripped at 10:00 hrs, resulting in load drop in Mumbai system. Mumbai’s islanding system that saves the city from major power outages was separated, however it could not hold as additional 900 MW load dropped at 10:05 hrs.”
It added, “Tata Power swiftly began restoration work to bring back supply from the three hydro units and Trombay gas and coal units as soon as the MSETCL transmission lines were connected. Tata Power started restoring supply to its consumers progressively from 12 noon onwards.”