Located on a dead flat piece of land about an hour-and-a-half’s drive from Upington and close to the Orange river, the curved solar collector mirrors, gleaming pipes and large molten-salt tanks of the 50 MW Bokpoort concentrated solar power (CSP) plant stand in stark industrial contrast to the vast expanse of grass and shrubs, distant rolling hills and vineyards.

Nevertheless, the R5-billion parabolic-trough plant offers a practical reference point for South Africa’s recent clean-energy progress and for the much-vaunted notion of Northern Cape’s solar radiation becoming its most valuable natural resource.

Developed by a consortium led by private Saudi Arabian utility ACWA Power, the plant entered commercial operation earlier this year and, between March 18 and March 25, operated continuously for 161 hours, at a load factor of 76%, before inclement weather intervened.

Such continuous operation is made possible by 9.3 hours of molten-salt storage, acting as a massive rechargeable battery, and also differentiating the CSP plant from the more commonly known photovoltaic (PV) plants, which currently only produce while the sun is shining.

Bokpoort CSP CEO Nandu Bhula expects this record to be broken as the transition from project site to operating power station gains momentum. The consortium of Acciona, Sener, TSK and Crowie has completed the engineering, procurement and construction of Bokpoort, with only a handful of Spanish-speaking contractors still on site to honour hand-over commitments.

This ability to operate when the sun does not shine is also reflected in the tariff received during the second bid window of the Renewable Energy Independent Power Producer Procurement Programme (REIPPPP), as well as the associated power purchase agreement (PPA) with Eskom. Bokpoort will receive R2.57/kWh over the 20-year PPA period.

However, Bhula notes that the tariffs associated with CSP in a subsequent bid windows has fallen, with the 100 MW Redstone power-tower CSP (being developed by ACWA Power and SolarReserve) to receive an average tariff of R1.46/kWh, inclusive of a premium of 2.7 times the base tariff if the plant sells power during peak periods. ACWA is optimistic of Redstone reaching financial close in the coming few months.

Similar price declines have been recorded across all of the other renewables technologies, as well as the more recently approved CSP projects. Besides Bokpoort, two other CSP projects are also in operation (Abengoa’s KaXu and Khi projects) while four other REIPPPP projects (Xina, Ilanga 1, Kathu Solar Park and Redstone) are under development.

ACWA Power’s Southern Africa business director Chris Ehlers, who was also recently appointed as the group’s global renewables COO, tells Engineering News Online that the company is determined to increase its CSP footprint in South Africa and the region, while pursuing gas-to-power and coal initiatives in parallel.

BEYOND SOLAR

ACWA has submitted a bid for the 300 MW Khanyisa discard-coal project, in Mpumalanga, under South Africa’s baseload coal independent power producers (IPP) programme, which Minister Tina Joemat-Pettersson indicates to be in adjudication. She reports that bids, with a combined capacity of 900 MW, have been received and that the department expects to announce preferred bidders in July 2016.

In addition, ACWA, which has a large gas-fired power plant footprint in Saudi Arabia, is closely monitoring developments surrounding South Africa’s gas-to-power programme, which is initially expected to be developed on the back of liquefied natural gas imports.

The Department of Energy has confirmed plans to procure a new 600 MW gas-fired power generation project, to be developed as a public-private partnership, and there is also a Ministerial determination for the procurement of over 3 100 MW of gas-to-power capacity over the medium term.

That said, ACWA remains enthusiastic about the REIPPPP, having submitted a bid for a further 150 MW power-tower CSP project under the so-called ‘expedited round’, while working on ‘Bokpoort 2’ for a future bid window.

Ehlers is hopeful that CSP will be included in the newly announced plan to add a further 1 500 MW of solar capacity across three solar parks in the Northern Cape.

Government wants the parks developed as public-private projects, led by IPPs, but including State-owned companies. A call for expressions of interest has been released by the IPP Office, which will be followed by procurement documentation once responses have been received on June 20.

In fact, he believes there is potential to develop hybrid CSP/PV projects, describing the current dichotomy between the two solar technologies as false. Yet, he is a strong CSP advocate, noting that, besides its ability to provide power during peak periods, the solution has a particular advantage in the area of localisation.

South Africa is said to be in a position to manufacture many of the components needed for CSP, owing to the fact that the plants incorporate a significant amount of steel fabrication. Bokpoort incorporated 40% local content and Ehlers believes the figure could rise to over 60% in a context where there is demand certainty, or where South Africa was deploying around 300 MW of CSP a year.

He also reports that lessons learned at Bokpoort, particularly its community-engagement successes, are already being transferred to ACWA Power’s other projects, including the giant Noor 1, 2 and 3 CSP projects, which the company is building in Morocco.

Once fully developed, the Noor Ouarzazate Solar Complex, on the edge of the Sahara desert, will be the biggest single site solar power facility in the world with a nameplate capacity of 580 MW.

“But we see just as much solar potential in South Africa and Southern Africa,” Ehlers asserts, reiterating ACWA’s stated goal of developing a 5 000 MW portfolio of renewables and conventional generation assets in Southern Africa by 2025.