Green Economy Journal Issue 56

ENERGY
ENERGY
The role of the Council for Geoscience in the
JUST ENERGY TRANSITION
to a LOW-CARBON ECONOMY
The reality of climate change requires that nations around the world think differently about
their role with respect to the environment. As the world moves towards a just transition to a
low-carbon economy, we have come to realise that the mineral resources sector is central to
attaining this objective.
BY THE COUNCIL FOR GEOSCIENCE
Pegmatite is a rock type known to host lithium, a mineral that is
in high demand for the development of batteries needed for electric
vehicles and energy storage from renewable sources such as wind
and solar. The pegmatite density map provides, for the first time, a
tool for mineral explorers to conduct detailed studies to quantify
lithium potential and to assess extraction and utilisation possibilities.
The role of carbon capture utilisation and storage
Even though Africa’s contribution to global carbon emissions is the
lowest worldwide, the continent is nevertheless one of the worst
affected by global climate change. Moreover, carbon mitigation has
become a priority worldwide. Several global commitments have been
made by the South African government in this regard.
To contribute to carbon abatement efforts, the CGS has been
implementing a CCUS project, with the specific intent of capturing
the carbon at a major emitting source and injecting it into a suitable
geological storage site. The selected site is located in Mpumalanga
province, near the town of Leandra, where there are a number of coalfired
power stations. Indeed, the Sasol plant in Secunda is undisputedly
the world’s largest point-source emitter of carbon dioxide. The rocks
being targeted for injection are the porphyritic lavas of the Ventersdorp
Supergroup (Figure 2). Through this project, the CGS hopes to capture and
inject into the ground up to 50 000 tonnes of carbon dioxide which, over
time, will reduce South Africa’s carbon footprint, thereby contributing to
global climate change initiatives and facilitating the country’s transition
to a low-carbon economy.
A
number of so-called “green” technologies, such as batteries,
wind turbines and solar panels require raw materials which
must be located, extracted and processed. To this end, it is
important that geoscience research and technologies are aligned
with the just energy transition initiative. Therefore, the South
African government, through the Council for Geoscience (CGS), has
been tasked to look for scientific interventions that will contribute
to the just transition trajectory.
The CGS, an entity within the Department of Mineral Resources
and Energy, is the custodian of geoscientific information in South
Africa. As such, the organisation aims use geoscientific information to
address issues ranging from mineral and energy security, groundwater
mapping, geotechnical assessments and mapping of geohazards
such as landslides, subsidence and earthquakes.
Over the last few years, the CGS has implemented several innovative
projects aimed at climate-change mitigation. These projects include
exploration into geothermal energy, carbon capture, utilisation and
storage (CCUS) and understanding the spatial distribution of the
minerals needed to achieve a just transition.
The exploration of minerals needed for an energy transition
There is no doubt that South Africa’s geology is endowed with a high
potential of mineral resources needed for the development of just
transition technologies. Specifically, these are copper, cobalt, zinc, nickel,
lithium and rare earth elements. The Northern Cape Province is thought
to be well-endowed with these minerals. As a result, the CGS has, over
the last few years, been conducting geological mapping resulting in the
development of a detailed pegmatite density map (refer to figure 1).
Figure 2. Geological cross-section showing the rock units (in green) targeted for carbon storage. The depth of the selected injection site is around 1 200 metres.
There is no doubt that South Africa’s geology is endowed with a high potential of
mineral resources needed for the development of just transition technologies.
Figure 1. Extent of the pegmatite belt in the Northern Cape Province of South Africa, highlighting the potential of the region for lithium-bearing rocks.
Figure 3. Geothermal gradient showing the spatial distribution of relatively
“hot” rocks targeted for exploitation.
GEOTHERMAL ENERGY
The International Energy Agency’s net-zero pathway recognises that,
by 2050, renewables must provide two‐thirds of the world’s energy
use, split between bioenergy, wind, solar, hydro-electricity and
geothermal energy. Geothermal energy is a type of renewable energy
sourced from hot source rocks deep underground.
The current gaps of energy supply in South Africa, manifested by
constant electricity cuts, can be closed by providing several energy
sources, including geothermal energy. In South Africa, the CGS has
been conducting multidisciplinary research that aims to locate
suitable host rocks (Figure 3). To date, scientists have identified five
areas that appear to be most prospective for the exploitation of
geothermal energy.
The research work started in Limpopo and KwaZulu-Natal
provinces. Exploratory drilling at these sites is intended to clarify
and quantify the depth of the hot rocks and, most importantly, to
assess the economic feasibility of geothermal energy generation.
This work is also meant to contribute to South Africa’s stated intent
of introducing renewable sources into the country’s energy mix, as
envisaged in the Integrated Resource Plan (IRP2019).
24
25