Mumbai power outage: Maharashtra sends notice to Tata Power

The Maharashtra government has sent a notice to Tata Power, one of the electricity suppliers of Mumbai, asking why the company’s Trombay power plant failed to comply with its directive to ramp-up production, which it said resulted in the metropolis coming to a grinding halt on the morning of February 27.

In a notice on March 2, the Maharashtra State Load Des­p­atch Centre (MSLDC), the apex body that ensures integrated operation of the power system in the state, asked the company to send detailed reasons for the power outage, failing which it threatened to take strict action against the company as per the Electricity Act 2003. The MSLDC said there was over-drawal of electricity of around 800-1700 Mw from the central sector grid on February 22 by Tata Power and it instructed the power system control centre to pick up hydroelectricity generation by 400 Mw to control this. However, Tata Power’s hydro generation did not pick up to the required capacity. This resulted in a threat to the grid stability, MSLDC said.

On February 27 —the day of the incident —at 9.30 am, the MSLDC directed asked the firm raise hydro and thermal generation to its full capacity as there were system constraints since only two transmission lines remained in service after the tripping of the 220 kV Mulund-Trombay line.

“However, under this emergency situation also TPC has not followed the directives of MSLDC control room and thermal, hydro generation was not ramped up as per system requirement. In addition, 220kV Trombay-Salsette 2 tripped on overload, which was not expected to happen as there are clear recommendations from the HLC committee constituted by MERC to remove overload tripping on 220kV lines. Subsequently, unit 5 and unit 8 at Trombay tripped causing load loss to the tune of 850 MW in [the] Mumbai area,” the SLDC said.

A Tata Power spokesperson said the notice is a part of laid out procedures during such events and does not suggest any fault on its part.

“We would like to reiterate that their assumptions about non-compliance with instructions are incorrect; under the new Deviation Settlement Me­c­h­a­nism regime, the MSLDC has the ability to enter the additional generation required into the system any time via a mechanism called VSE (Virtual State Entity), which takes only 15 seconds to activate. The first communication from MSLDC to pick up generation occurred at 09.30 [am], according to phone recordings available at both ends and witnessed by top authorities present at Trombay. We responded immediately to the issue that had evolved as a result of MSETCL's grid tripping. Maharashtra State Electricity Transmission Company and MSLDC should not absolve themselves from the responsibility of failing to take any preventive measures,” the spokesperson said.