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Energy Minister Dipuo Peters on Friday launched the South African Carbon Capture and Storage (CCS) Atlas for the geological storage of carbon dioxide (CO2) deep underground.
The Atlas highlighted, at a theoretical level, that South Africa had about 150 Gigatons (Gt) of storage capacity, and where this capacity was located.
This was significant because without the storage potential, South Africa’s CCS plans would not have been able to go ahead. “This important milestone is saying go, instead of no-go,” reiterated Central Energy Fund CEO Mputumi Damane.
The majority of the storage capacity was located offshore, which was not the best outcome for South Africa, as there were high logistical costs associated with offshore storage, considering that the country’s CO2 emission sources were predominantly inland, in the Mpumalanga province.
The largest storage volume, representing about 98% of the total storage potential, was present in the Mezoic basins along the coast of South Africa. This storage capacity was mainly in the capacity of saline formations in the Outeniqua, Orange, and Durban or Zululand basins.
It was estimated that the Outeniqua basin had storage capacity of some 48 Gt, the Orange basin could store about 56 Gt, and the Durban/Zululand basin had 42 Gt of storage potential.
Less than 2% of the estimated storage capacity in South Africa occurred onshore. About 0,46 Gt for the onshore Zululand basin, some 0,40 Gt at the onshore Algoa basin, and about 1,2Gt in what were today considered unmineable coal seams in South Africa.
The South African Centre for CCS would now concentrate on qualifying the work of the Atlas by doing further drilling and seismic studies in the onshore areas identified.
The next major milestone was to have a test injection site up and running by 2016. A test injection site would need to be identified, and operational to determine the suitability of the local geology as a storage medium, as well as the dispersion and transformation of CO2 in South African rocks.
South African Centre for CCS head Dr Tony Surridge told Engineering News Online that the centre had received financial support from the UK’s Department of Energy and Climate Change to further investigate and qualify the Durban/Zululand basin’s onshore storage capacity.
This would take the storage capacity from a theoretical level, to a more realistic level. It was possible that the storage capacity of the various basins was revised downwards as more information was made available.
The South African Centre for CCS had also submitted a proposal for financial assistance from EuropeAid, to fund further investigation into the onshore Outeniqua basin.
CCS Atlas project manager Marthinus Cloete, from South Africa’s Council for Geoscience, explained that the atlas clarified where the potential for storage existed, and that the estimates would be refined with basin and site specific information through seismic testing and drilling.
South African Centre for CCS board of governors chair Barry MacColl emphasised that CCS was critical to finding a cleaner future for South Africa, which emitted some 440-million tons a year of CO2.
He also highlighted that while the centre progressed with refining work in the Atlas, it would also need to tackle the challenges of raising awareness on CCS, developing skills in this area, as well as working on the policy and legal frameworks for CCS.
“This technology is still evolving, from a commercial deployment perspective, and remains a global matter requiring a collective approach and international co-operation at both the policy and technical levels,” said Peters.
She added that CCS was one of a range of options that South Africa was focusing on in order to mitigate greenhouse gas emissions and meet global climate change commitments.
Increasing the use of renewable energy and implementing energy efficiency measures, were some of the other options to satisfy the country’s determination to move away from a dependency on coal.
However, Peters added that it would be irresponsible to not use the country’s coal resources to eradicate energy poverty in South Africa. Investment in CCS would allow South Africa to use its abundant coal reserves while protecting the environment for future generation.
