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

Anumber 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).

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.

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).