ANOTHER major blackout occurred on Saturday night as sabotage on one transmission line that feeds power to Quetta rapidly cascaded through the entire transmission system, causing power plants to trip and shut down one after another across the country.

Within minutes, all but a handful of power plants fell, leaving little more than 600MW of electricity in a system that was generating more than 9,000MW at the time.

Also read: Parts of Pakistan still without electricity, following breakdown

Two earlier acts of sabotage had placed all the burden of Balochistan’s full load onto one transmission network that runs between Guddu, Uch, Sibi and Quetta. When two pylons of a key line in this network were blown up, the entire load fell on the link that connects Guddu with Quetta, something that Guddu’s grid station could not bear.

All three grid stations of the aging plant tripped as a result, which sent a disturbance cascading up and down the entire transmission system taking out power plants one by one throughout the country. The whole process took minutes to happen, but hours to reverse.

One positive to note through this affair is how the various components of the power system worked together to restart the system.

The hydel plants operated by Wapda, the thermal power plants of Pepco, the independent power producers and K-Electric all coordinated to energise each others’ power plants in the dead of night.

Wapda energised Pepco’s plants in northern Punjab, Pepco energised K-Electric (although on their Twitter feed K-Electric claim they started up “in island mode”, meaning they received no assistance in re-energising their system), and K-Electric energised Hubco.

But this not the first time that our transmission grid has been brought down by a single event in one section. There were two blackouts in December, both centred on Guddu, that also cascaded through the system in this way, although their effects were felt south of the plant.

It is worth asking at this point, how hard it is to have systems in place that can serve as circuit breakers to prevent this sort of cascading, and what is being done to put such systems in place.

The growing frequency of blackouts of this sort, that originate in a single event on the national grid but travel rapidly through the system to plunge entire areas of the country into darkness for prolonged periods, highlight the serious vulnerabilities that are nestled in our power system, and for some reason these vulnerabilities are coming increasingly into play these days.

The power system is already groaning under the load of financial problems and efficiency issues, but this is one challenge that surely should have a simple solution.

Is somebody in the power bureaucracy following up on this? Is somebody asking what can be done to provide synaptic protections in the grid to ensure that adverse events are localised?

Published in Dawn, January 26th, 2015

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