Sunday morning scare: Mumbai sees 70 min power outage as power lines trip

In a near repeat of the October 12 2020 power failure in the city electricity supply went kaput on Sunday but only for 70 minutes One of the stateowned power lines that bring power to the city tripped thereby creating shortfall of 8001000 megawatts MW to the island city some eastern and western suburbs at 948 am affecting train services tooAreas such as Carnac Parel Mahalaxmi Dharavi Backbay Grant Road BandraKurla Complex Wadala Chembur Trombay and Mankhurd were affected when the TrombaySalsette transmission line operated by the Maharashtra State Electricity Transmission Company MSETCL trippedEnergy minister Nitin RautAt that time the demand in the service area of the Brihanmumbai Electric Supply and Transport Undertaking BEST was 414 MW and it could not supply a single unit because it buys power from others for distribution and it does not have its generation capacity Suburban supplier Adani Electricity Mumbai Ltd shed a load of 112MW when the demand was at 877MW Similarly Tata Power shed a load of 383MW when its demand was 589MW Stateowned Mahavitaranrsquos area remained unaffectedEnergy Secretary Dinesh Waghmare said alternative lines were used to shift load between after 1008 am and all loads in Mumbai were restored in 70 minutesThrowbackThe outage rekindled the memories of the major incident in 2020 if not in terms of the longer outage but the occurrence In 2020 the supply in some parts of the city could be restored only after a day However this time instead of 440kv the 220kv line tripped thus creating a relatively less impact But it did affect the cityrsquos embedded generation at Tata Powerrsquos Trombay plant which also tripped as a cascading effectWorkers carry out maintenance work on a high tension tower of Tata Power at Dharavi File picAfter the 2020 outage the government and Central electricity agencies had probed into it and recommended that the cityrsquos power infrastructure needed an urgent upgrade More lines must be built to carry power from outside to cater to the growing demand they said The pending work of such lines was expedited by the Maharashtra Electricity Regulatory Commission MERC by transferring it to Adani Power citing inordinate delay in construction by Tata Power Early this month the Appellate Tribunal for Electricity upheld Maharashtra regulatorrsquos decision of awarding a Rs 7000crore transmission project to Adani on a nomination basis but the aggrieved petitioner Tata Power is expected to move the Supreme Court in the caseNo cyberattack Energy ministerA possibility of cyberattacks were also probed in the 2020 outage and Maharashtra cyber department report had confirmed that a malware had hit the system and about 14 Trojan Horses and 8 GB of unaccounted data was foundTalking about Sundayrsquos incident Energy Minister Nitin Raut told midday that it was not a cyber attack ldquoI have gathered all the information There is no cyberattack It was purely a technical issue that our engineers and technicians resolved quickly Our priority was to restore the supplyrdquo he saidNitin Raut energy ministerThe minister has ordered a toplevel probe ldquoThe responsibility will be fixed and action taken against the guiltyrdquo he saidBlame gameWhile some industry experts allege that Tata Powerrsquos Trombay plant failed once again and that there was a delay in ramping up of alternative power sources to mitigate the deficit the company claimed that its Trombay plant was intact and it did not delay to bring in power from Bhira hydro Plant ldquoElectricity was restored by Tata Power in around an hourrdquo a statement saidldquoAt 950 am in south Mumbai Chembur Bandra and Santacruz suburbs along with Central and part Western Railway power supply got affected due to tripping of MSETCL line at MSETCL Trombay receiving station that connects to Tata Power transmission system This resulted in the tripping of Trombay generation and cascade tripping of some internal lines affecting 850 MW load of all companies in Mumbairdquo said Tata Power spokespersonAdani Electricity Mumbai Ltd spokesperson said ldquoTodayrsquos power outage was caused due to tripping of 220 kV transmission line and subsequent outage of Tatarsquos Trombay power plant Adani Electricity consumers were largely unaffected by todayrsquos power outage as we were able to ramp up our generation at Dahanu in a very short time This helped early restoration of consumers in South MumbairdquoAction neededIn October 2021 the Energy Department submitted a report to the cabinet regarding the 2020 power outage and cited several reasons that led to the blackout It has made recommendations some of which are being followed to avoid recurrence of the eventThe report said the inadequate islanding mechanism and insufficient electricity generation inside the city limits lack of coordination between the companies load despatch centre and subcentres nonavailability of hightech emergency handling equipment at the load despatch centre and lack of a standard operating procedure SOP had caused the outageThe first and foremost recommendation was to have a revised SOP for the planned outages maintenance and repairing activities across companies Other recommendations were about working on the deficiencies and causes given Emphasis will be given on increasing electricity generation within the city limits and a task force has been formed to study the effects of new trends and technology on the Mumbai network The expert panel that made the recommendations said a plan has been submitted to safeguard critical information infrastructure through cybercrisis management and that the IT infrastructure has been audited and cybercleansing has been taken up as the suggestions70 minutesPeriod power supply was hitNo train services for over 20 minutesCommuters walk on tracks between Mumbai Central and Grant Road stations on SundayThe outage also brought local trains to a standstill Due to cancellation of services and trains being stranded on tracks some passengers walked on railway tracks to reach their destinations ldquoTrains did not move for over 20 minutes from Churchgaterdquo said Jay Dixit a commuter ldquoThere was no train movement between Churchgate and Andheri As an interim measure supply was extended from Jogeshwari substation and services were restored at 1044 am The regular supply was restored at 1053 am On WR about 50 trains were cancelled and 140 trains delayed The Delhi Mumbai Rajdhani arrived at Mumbai Central late by 30 minutesrdquo WR CPRO Sumit Thakur said ldquoCentral Railway services were affected after power supply tripped on harbour and mainlines between 949am and 952 amrdquo said Shivaji Sutar chief PRO CR A Tata Power Company statement said ldquoThis morning the MSETCL transmission line from Kalwa to Trombay had massive voltage fluctuations causing tripping of Trombay Salsette1 on overload This affected the south Mumbai electricity distribution system However Tata Powerrsquos Hydro plants were intact and the Bhira Hydro Plant got islanded and synchronised The electricity has been restored by Tata Powerrdquo Rajendra B Aklekar