Frank Duvenhage, Pancho Ndebele and Robey Labuschagne lament that concentrated solar power – which uses the thermal part of sunlight to heat water into steam, spin a turbine and run a generator – is overlooked by the public and policymakers alike

South Africa’s economy has been hit hard by the recent global and local lockdown. The manufacturing sector, which is the foundation of any strong, resilient economy, has taken one of the hardest knocks. Contributing 13% to the national gross domestic product, it shrunk 30.2% in the second quarter of 2020, compared with the corresponding quarter of 2019. This is partly due to a pre-pandemic economic downturn, but most recently due to the strict lockdown measures.

This, however, does not need to remain the case for South Africa. In an article published in Engineering News & Mining Weekly on July 24 (South Africa must find niche in ‘tectonic’ shift towards greener industries), it was reported that Trade, Industry and Competition Minister Ebrahim Patel emphasised the important role that shifting to ‘greener industries’ can play in finding new opportunities for economic growth and employment. One such South African industry that is overdue for ‘greening’ is the energy sector. South Africa has the second-highest sulphur dioxide emissions in the world near Kriel, in Mpumalanga, as a result of coal power plants.

Synonymous with green energy are technologies such as solar photovoltaic (PV), wind and hydropower. However, there is one somewhat unknown solar technology that is overlooked by the public and policymakers alike: concentrated solar power (CSP). Put simply, CSP uses the thermal part of sunlight to heat water into steam, spin a turbine and run a generator.

Sounds familiar? That is because South Africa has a long and illustrious history with fossil-fuelled thermal power in the form of its many coal power stations and petrochemicals industries (and one nuclear power station). While their environmental impact is certainly detrimental, their impact on South Africa’s engineering sector has been overwhelmingly positive.

They have given South Africa the in-house expertise in steam power, pressure vessels, power-plant design and metallurgical engineering that rivals even that of Germany. This is great for CSP, because, unlike PV and wind technologies, it relies on all these existing fields of expertise, instead of highly specialised imported components like laboratory-grown silicon PV cells and composite wind-turbine blades. CSP is certainly not plug-and-play, like the other green energy technologies, but it has something they don’t: storage.

Storage is the holy grail of renewable energy, owing to its reliance on variable and unpredictable weather systems. CSP’s storage comes in the form of thermal batteries, where heat is stored in molten salt. This allows it to both store and generate electricity during the day, and when the sun sets, to discharge the heat from these batteries to produce steam and, in turn, near-baseload electricity when it is dark.

The value of CSP to the future of a greener energy sector is clear. It is, however, important to recognise its value for green industrial growth. South Africa suffers from growing unemployment and a shrinking economy. It is therefore essential that any potential green industries must directly stimulate the local economy. Emvelo’s Ilanga CSP1, a 100 MW power plant near Upington, has done just this. It filled about 1 300 of the total 1 500 construction jobs with South Africans, and employs about 100 people from the area in its operations since 2018. Further, it exploited South Africa’s local manufacturing and engineering capabilities, resulting in 60% of the total components used in the R11-billion plant being supplied by South African companies.

Except for the mirrors used to concentrate, and the receivers which absorb the solar radiation, almost all other parts of a CSP power plant can be supplied by the local, currently suffering engineering and manufacturing sector. Welders, boilermakers, engineers, inspectors, metal pipe manufacturers, sheet-metal suppliers, civil construction companies and power plant operations personnel can all contribute to growing the South African CSP fleet and economy.

While government emphasises job creation and economic growth, it cannot be sustained if the right industries are not supported by enabling policies. Considering CSP’s value, and the fact that South Africa has some of the best sunshine in the world, it is a shame that the 2019 Integrated Resource Plan (IRP) ignores CSP completely. This is because the IRP makes use of a least-cost approach to modelling the national electricity generation mix. The final cost of electricity, however, is not the only determining factor; the IRP follows certain policy adjustments, to include socioeconomic value and environmental impact.

Despite these policy adjustments, CSP is still excluded, demonstrating the lack of understanding by policymakers of the value of CSP to both green energy (environmental) and local industry stimulation (socioeconomic). The challenge when using strict least-cost approaches to energy planning is that it favours cheaper technologies, like PV and wind, typically imported from countries where they have seen high penetration levels due to policy-supported subsidies. This prevents any local growth of these, and other green energy industries.

The answer is not to include CSP at the cost of other green technologies, or to halt the import of cheap ones. It is simply to give CSP the opportunity to partake in this green revolution through the inclusion thereof in future electricity infrastructure development. If government is serious about using green industries to ‘pivot’ the South African economy towards recovery, as Patel put it, then it cannot afford to miss opportunities like those from CSP. There is a need to recognise that the cheapest technology is not always the best for local industrial growth.

Dr Duvenhage is an engineer with a passion for sustainability and Africa and currently works in the industrial water treatment sector after completing his studies on CSP in South Africa; Ndebele is a ‘green’ entrepreneur and energy, water and sustainable development engineer, and is the founder of Emvelo; and Labuschagne is a mechanical engineer with seven years’ experience in production