Our Unending Power Woes

Is the overall consumption of energy by a household, in a period say one day or one week, proportionally lower in case of load shedding during that period compared to if the supply had been continuous and uninterrupted?

A definitive answer to the above question would be available only if our power supply utility, KPDCL, has undertaken a scientific study to understand and evaluate the impact of power curtailment on the overall consumption of energy by the consumers and to assess its impact on its own power infrastructure system, like feeders and receiving stations.

The argument one is trying to make here is that the total consumption of energy (units) by a typical consumer in a day, in a power curtailment scenario, is only marginally less than in a 24x7 uninterrupted power supply scenario. In turn, by restoring to power curtailment KPDCL might be straining its own power infrastructure (distribution network, feeders and receiving stations) as the load (MW) at the feeder level is vastly increased, when supply is restored after a shutdown.

When a distribution company resorts to power curtailment, the consumers (consciously or unconsciously) tend to plan their power usage to match the power availability schedule; they reschedule their electricity run activities to match the supply timings.

Talking here essentially of the domestic sector during power curtailment, except for lighting, there is a planned redistribution of the usage by the consumers so as to squeeze their 24-hour energy requirement into the time periods in a day during which supply is available. For the lighting segment with the introduction of energy efficient lighting fixtures, the proportional consumption of energy for lighting has substantially reduced to around one fifth – a 20w fixture suffices instead of the old 100w bulb.

Given our extended power curtailment periods power invertors have become ubiquitous, and a large proportion of consumers have installed them. Invertors, mobiles and power banks are all charged during the period when supply is available, rather than a 24-hour window when the supply is uninterrupted. Installation of energy efficient lighting fixtures and the wide acceptance and usage of invertors has taken lighting segment of our consumption out of the power curtailment equation.

However, it is worth mentioning here that since invertors have their own inefficiencies (around only 90% efficient) we lose about 10% of the energy required to charge it; for every ten units of energy that an invertor needs to charge it, it in turns delivers only nine units, one unit is lost in the process.

Whether it is for cooking or the use of water heaters/ geysers, two activities where bulk of our domestic energy consumption occurs, the consumers alter the usage timing to align with power availability and thereby the consumption of energy by these appliances is nearly the same as it would have been without the curtailment i.e., in an uninterrupted power supply scenario. In 24x7 power supply scenario one would switch on the geysers sometime before one needed hot water, but in a power curtailment scenario one tends to keep them on literally all day as one is never sure when a shutdown will be taken.

Likewise, running of washing machine and subsequently (electric) ironing of clothes is amongst the activities that are rescheduled and undertaken only when there is power supply. All our electric run kitchen gadgets are operated in the same manner. Incidentally, given the way refrigerators and deep freezers run, they use the similar amount of energy per day, with or without power curtailment.

On resumption of power supply all the appliances tend to be immediately switched on (many of them are already on ‘ON’ mode waiting for resumption of supply) literally at the same time thereby putting huge strain on our existing power infrastructure (receiving stations, feeders?). The drawdown of energy from the system at that point in time increases exponentially and the load thereof is far more than what it would have been if there had been a continuous and uninterrupted supply of power. One wonders whether this phenomenon of power curtailment should be called ‘load gain’ rather than ‘load shedding’.

Having said that, compared to summer the load shedding in winter is relatively more effective in reducing the overall energy consumption. Energy consumption of appliances like oil heater, blowers, which would otherwise be kept running 24x7, is reduced during the curtailment period. In winter the lighting load triggers in early in the evening till late morning but then that is largely taken care of by the invertors.

However, the above arguments hold true only for the domestic sector. Unfortunately, the most severe impact of the power curtailment is on the industrial sector. Unlike the domestic users, the industrial users suffer the most as their timings for usage are far less flexible. Commercial sectors like shops and similar establishments tend to make things work with invertors or generators.
So, if the power curtailment does not substantially reduce the overall consumption of energy but instead puts pressure on our power distribution network then the question that begs an answer is ‘why do we have power curtailment and who benefits from it?’.

Is it to cut down the energy losses due to the dilapidated, outdated, antiquated, archaic, over stretched power distribution system which sucks and wastes a large percentage of energy supply?

Iftikhar A Drabu is a civil engineer from Srinagar.