Page 12 - Energize May 2021

Mind the gap
he low carbon energy transition needs
to use technologies suited to the daily
Tand seasonal fluctuations in the load
demanded by the grid. Sufficient electrical by Ken Gafner, Single Destination Engineering (SDE)
generation capacity needs to be available
immediately to suit demand. Any shortfall
would need to be provided by increased The right energy mix will help us transition to the low carbon future
energy generation or reducing load. needed to mitigate the effects of climate change.
Photovoltaic (PV) solar and wind
offer the lowest cost of generation and
contribute negligibly to climate change.
Unfortunately, a massive build of wind and Integrated Resource Plan (IRP). This defines the generation to be procured to meet the energy
PV solar alone is not able to support the needs of South Africa over the next 30 years. The IRP has been subject to political interference
fluctuating demand of grid adequately as over the last ten years. Fortunately, this appears to have abated and the latest iterations of the
PV solar is only available during daytime IRP are more in line with the actual needs of South Africa.
and wind often falls off dramatically in the
early morning hours. The ideal gap fillers
In addition, South Africa has a morning The ideal gap filler is where the load profile of the grid is encouraged to fit as closely
and evening load peak. The difference as possible to the available grid generation capacity by reducing the overall peak loads
between the peak load and the base load imposed on the grid. Examples of this include Time of Use (ToU) tariffs leading to changes
will continue to increase as more PV solar in working hours, utilising existing own generation, promoting new own generation and fuel
and wind generation is connected to the switch projects.
grid. PV solar and, to a lesser extent, wind ToU tariffs have energy costs which differ for peak, standard and off-peak periods.
generation, needs to be complemented by Peak period energy is the most expensive which provides a strong incentive for consumers
additional dispatchable peaking generation and industry to reduce and shift consumption to standard or off-peak periods. The existing
or load reduction. ToU tariffs already have a substantial peak period energy charge. All that is required is for a
If this gap is not filled, then the load compelling business case to be established for industry and consumers to convert to ToU
shedding that has plagued South Africa for tariff. The widespread adoption of ToU tariffs and associated consumption profile changes
the last 13 years will continue. will then occur naturally. This would include increased adoption of own generation to offset
The pathway for the development of peak period consumption. Increasing the availability of cost-effective fuel and the correct
generation in South Africa is defined in the government initiatives to promote this are essential.

Figure 1: Electricity demand and supply assuming optimal wind and solar PV deployment (South Africa’s Energy Transition: Tobias Bischof-Niemz and Terence Creamer)

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