Page 6 - Energize November 2022

COVER STORY

Optimising generation efficiency:

The importance of a natural gas transition

in achieving South Africa’s energy security

by Wayne Glossop, Wärtsilä

he multi-faceted energy action plan announced by President Cyril Ramaphosa in
July 2022 could be sufficient to alleviate our current load shedding crisis, but any
Tslip in times or effectiveness will leave South Africa in continued darkness for many
years to come. And while the focus is rightfully on the maximum pursuit of adding more
renewables to the system, our energy security will remain compromised unless balancing
technologies are added as aggressively in parallel, to enable as much renewable energy
as we can implement.
Energy security is defined as ‘the uninterrupted availability of energy sources at an
affordable price’. While there is clearly an urgent need to address the current acute issues
with regards to Eskom’s fleet of coal-fired power stations – initially to simply provide
energy to keep the country’s economic engines running – Wärtsilä’s own energy studies
show the important role that natural gas could play in maintaining a reliable, cost-
effective and cleaner energy supply in the future.
Our extensive, and transparent, modelling takes into consideration multiple different
scenarios that could unfold, from a ‘perfect world’ scenario to factoring in specific
realities of the local landscape. The conclusion is that transitioning from coal dependence Wayne Glossop
to a renewable energy future enabled by gas energy can allow for improved energy
availability at an affordable price, while also reducing carbon emissions.
in the current local absence of battery
Within the debate: Wärtsilä modelling outlines the real-world role of gas technology and significant storage
There is a common debate in the industry locally which questions whether we need technologies – it is the coal fleet and
gas and, if we do need it, what its role should be. Gas is seen as a costly dirty fossil fuel, diesel turbines which come to the fore in
which goes against the grain of how local players wish to improve our energy system providing electricity on a daily basis.
in the future. People question why South Africa would consider bringing in natural gas, Diesel is far more expensive than gas,
when renewable energy and alternate technologies are coming to the fore and battery from the perspectives of the economy,
prices are improving. business and consumers, while coal is far
Our scenario planning, of necessity, includes provision for actualities that are likely dirtier, with significant carbon emissions.
to unfold, such as (but not limited to) reduced coal availability, transmission failures, For these two reasons, Wärtsilä
Koeberg outages and delays in the commissioning of new capacity. We describe around advocates a shift to a cleaner and more
20 measures that would all slow down the movement towards increasing the capacity of cost-effective system with the use of gas.
renewable energy to add into the grid. In a perfect world scenario, the role
Our planning outlines alternative measures that can be taken via the introduction of gas includes flexible peaking, with its
of gas, in response to calls from some quarters to fast-forward the introduction of ability to balance the fluctuating power
renewable energies, and storage and integration technologies, while moving towards a requirement in the electricity network,
reduction in the use of coal. and operate during periods of high-level
Our modelling places an emphasis on the ‘insurance’ role that gas could play in the demand for electricity, or where there
power system, being able to step in and offer high levels of dispatch capacity where are shortfalls of electricity supply.
renewable energy sources are currently constrained. Further, we have been able to However, the role of gas additionally
show that an introduction of natural gas into the system would be able to provide both a offers system contingency reserves, as
reduction in the total system costs – of approximately 10 to 15%, which equates to 10 to well as providing operational reserves
$15 billion over a 10-year period – while also bringing a reduction in carbon emissions. to the power system. It is important
Looking at the power system today, the system operator relies predominantly on to recognise and acknowledge this
diesel and coal to balance the system, while aspiring to bring renewable energy into the flexibility that can be brought into the
mix in a greater proportion. Unfortunately, when attempting to balance in renewables – system through the introduction of gas in

energize | November 2022 | 6