Page 51 - Energize November 2021

VIEWS AND OPINION

Don’t like load shedding? Reduce your demand!

skom’s energy availability factor (EAF) continues to decline in actively replaced old fluorescent tubes with LED equivalents and
2021. At the beginning of Eskom’s financial year (April 2021), improved or replaced their HVAC systems. Some have defected from
Ethe EAF was at 59%. It hit an all-time low in October of 57,5% the grid entirely, but most are still grid-tied.
but had recovered to 62% by mid-November. All against a target of Load shedding has been with us since 2008, with a few years of
70%, which is low. Traditionally, the EAF target was 80%. The balance respite. But we can expect the situation to remain as it is for many
was made up of 10% out of service for routine maintenance and 10% years yet. As many more people work from home now, interruptions
allowance for unscheduled maintenance (breakdowns). to electricity supply often disrupts workflow and hampers
Today, as I write this article, we have 4800 MW offline for routine productivity.
maintenance (11% of 45 000 MW) plus 16 800 MW out of service for Not all interruptions are the result of load shedding. Municipal
unscheduled maintenance (37% of 45 000 MW). Therefore, we have distribution equipment fails from time to time and cable theft is still
a total of 21 600 MW out of service (48%). a major problem.
Fortunately, we also have an extra 6000 MW from the The cost of implementing de Ruyter’s suggestions are
independent power producers on the grid, but solar PV without significantly lower than running a petrol generator for a few hours a
battery storage doesn’t really help after sunset. day, or investing in a 5 kVA inverter, 20-odd PV panels and a multi-
Simply put, we need to live within the amount of electricity cell storage battery.
actually available to us. We need to get everyone to understand how their contribution
The power utility has stated repeatedly that it needs additional would help. We should become evangelists of what a former Eskom
capacity of between 4000 MW and 6000 MW and keeps appealing to CEO called “living lightly”.
its customers to use electricity sparingly. Summer in South Africa is, for many, braai time. The more we
Load shedding is implemented to protect the system from a use our braais instead of our electric ovens, the less electricity we’ll
collapse. The National Control Centre, which was put in place to use. It’s time to discover how to use your kettle braai instead of your
ensure supply met demand, now ensures demand does not exceed electric oven. Your microwave oven is also a great electricity saver.
supply. The control centre’s task is to ramp power stations up and If you’re prepared to spend some money, I suggest you invest in
down to keep supply and demand balanced. It does this by watching a solar geyser and possibly a gas stove.
the frequency. The nominal frequency is 50 Hz, but as demand Perhaps we should consider it to be a “drought” of electricity.
increases, the frequency begins to fall. At a certain point, additional We understand our water shortages and know we need to control
generation capacity is brought online to increase the frequency back our consumption. It’s time to face the challenge and use electricity
to 50 Hz. As the demand decreases, the frequency rises. Generation as if it were in short supply. Because it is and is likely to remain so for
capacity is then curtailed to reduce the frequency back to its nominal many years yet.
value.
Today, the frequency falls not because load has increased, Send your comments to rogerl@nowmedia.co.za
but because generation capacity has decreased. To increase the
frequency, the control centre must reduce load.
If we want to reduce the level and frequency of load shedding,
we need to ensure that the load never exceeds generating capacity.
In other words, we need to use as little electricity as we can to keep
Eskom from instituting load shedding.
As residents, we can do this very easily. Andre de Ruyter, Eskom’s
CEO, speaking at the recent State of the System announcement,
explained that if the residential sector were to switch off lights in
unoccupied rooms, reduce the amount of time their pool pumps ran,
reduce the temperature of their geysers to 60ºC, and replace their
50 W halogen downlights with low-wattage LED equivalents, the
overall load could be reduced by almost 3000 MW, making the need
for load shedding less frequent.
South Africans can get over the inconveniences of making
the suggested changes if it means we can reduce or prevent load
shedding.
There are many in the commercial and industrial sectors which
have already made drastic changes and reduced their electricity
demand on Eskom. Many have installed rooftop PV panels, not only
to save money, but to reduce their dependence on Eskom. They have

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