Page 42 - Energize April 2022

VIEWS AND OPINION

The path to decarbonisation: who owns

grid resilience?

BY KEN GAFNER, SINGLE DESTINATION ENGINEERING (SDE)

arbon dioxide and certain other gasses accumulate in the earth’s atmosphere,
trapping radiated heat, thus leading to an increase in average temperatures over
Ctime. Concerns related to the impact of man-made greenhouse gas (GHG) emissions
on the earth’s climate became widespread in the 1980s.
This led to the 1992 United Nations Framework Convention on Climate Change. The
Conference of the Parties (CoP) is the decision-making body with annual conferences at
which all countries are represented to negotiate a Protocol intended to be adopted and
ratified by member countries.
The protocol accepted as the defining the mechanism for monitoring reduction in GHG
emissions was the Kyoto Protocol (1997). This protocol failed to achieve the desired impact
as the US (largest contributor) refused to ratify then withdrew and China (second largest
contributor) was classified as a developing country and exempt from reducing emissions.
The protagonists and denialists of climate change were equally vocal. World CO 2 emissions
have increased from 22,5 Gt in 1997 to 33 Gt in 2021; an increase of nearly 50%. (Source IEA
Global Energy review.)
The commitment to meaningful greenhouse gas emissions reduction has grown more
unified over the last 30 years. The latest CoP26 in Glasgow 2021 resulted in the Glasgow
Climate Pact which recognizes this decade as key to limiting average global temperature
rise to as near as possible to 1,5°C. An increase of 2,4°C is predicted based on current Ken Gafner
commitments.
The South African 2017 greenhouse gas emissions were 556 million metric tons of CO 2 eq
(CO 2 equivalent: The effect of different gases is weighted in relation to CO 2 and the weighted electricity demand during the morning
totals added). South Africa is the 13 largest emitter and significantly above world per capita and evening peak periods. This minimises
th
emissions (8,2 tons CO 2 eq per person vs. a world average of 4,7 tons CO 2 eq per person). the necessity to operate plant at part load
This is primarily due to 90% of South Africa’s electricity generation being from coal-fired with higher emissions. This is the principle
power stations. behind time-of-use (ToU) tariffs with
Reducing emissions in line with world trends is important to South Africa, as it is likely lower electricity tariffs during off-peak
that countries which do not meet emissions reductions targets will be prejudiced with less times, reasonable standard tariff rates and
favourable trade conditions in future. expensive peak rates which correspond
to the morning and evening peaks. The
The carbon reduction toolbox winter peak tariffs rate is approximately
A significant proportion of emission arise from electricity production. Other major three times the standard rate and
contributors including transport and industry are not considered here. incentivises users to reduce consumption
in peak periods, flattening the daily
The carbon reduction toolbox includes: demand profile. Tailoring the ToU tariffs
• Changing usage patterns and energy efficiency and incentivising consumers to move to
• Solar and wind generation ToU could significantly reduce morning
• Low carbon flexible generation and evening peaks.
• Low carbon baseload generation Solar and wind powered renewable
generation has been adopted almost
The most effective and least cost method of reducing emissions is to reduce the demand universally as the technologies to reduce
for energy. Significant reductions can be achieved through energy efficient buildings and emissions. They have been widely adopted
processes. Existing incentives to promote energy efficiency should be promoted and but suffer from the key limitations that
developed further to reduce energy demand. they are not dispatchable and require
Electricity tariff structures can incentivise change in electricity usage patterns, to reduce significantly more space than gas,

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