Credit: FernandoAH

The Bokpoort project company, in which Saudi Arabia’s ACWA Power is the largest shareholder, started salt melting operations for the 50 MW plant in June. 

The plant has 9.3 hours of storage capacity using a molten salt system and the solar field features loops of parabolic trough solar collector assemblies. 

Construction on the US $565 million project began in 2013 and commercial start-up is expected in December 2015. The facility is situated at Grobblershoop, 120 km south east of Upington, in South Africa’s Northern Cape Province.

Once completed, Bokpoort would have one of the largest storage capacities held by CSP projects.

In comparison, SolarReserve’s 110 MW Crescent Dunes tower CSP project in Nevada, US has a storage capacity of 10 hours using molten salt.
 

The above chart representing the South Africa CSP market is taken from the CSP Today Markets Report 2015: South Africa

According to Bhula, the 380,000 square-km Northern Cape Province alone could produce 5,000 MW of CSP capacity.

“This seems huge but South Africa is power hungry and once the first few CSP plants prove their worth, there is no doubt that 10% of the country’s energy mix in Solar CSP is achievable”, Bhula said.

The South African government has suggested power generation capacity needs to double to over 80 GW by 2030, to meet rising power demand.

The government has an overall target to deploy 1,200 MW of CSP by 2030 but the actual figure could be a lot higher and will depend greatly on the government’s support for CSP projects in the national Renewable Energy Independent Power Producer Procurement (REIPPP) program.

The REIPPP invites developers to propose new projects in bidding rounds. The REIPPP is an excellent example of how Independent Power Plants can be introduced into an energy market with full governance, full accountability, full transparency and a fair, competitive process, Bhula said.

Construction costs in South Africa are falling and they will fall further if the government continues the renewable program with new bid windows and increases the scope of IPPs, he said.

“The cost of CSP could become extremely competitive if bid windows are sufficiently lucrative for foreign companies to set up operations in South Africa,” Bhula said.

Missing links

“The biggest constraint we have in South Africa is probably the grid connection in the Northern Cape, as there are not enough feasible transmission integration options,” Bhula said.

There must be a significant investment in transmission capabilities so that firms can capitalize on the available capacity and potential, he said.

Bokpoort CSP represents the first investment by Saudi Arabia’s ACWA Power in South Africa, as a direct shareholder. The plant is at the end of its construction phase, with 93% of construction completed.

In addition, about 20-30% of commissioning works have also been carried out, Bhula told CSP Today.

The company initially planned for a 75 MW station but the South African renewable program only allocated a 50 MW licence. “So we are restricted by our power purchase agreement,” Bhula said.

ACWA Power does not currently hold a licence to upgrade the plant but the firm is developing potential further capacity projects at the Bokpoort site as well as other projects, such as the 100 MW Redstone CSP Tower which the company is co-developing with SolarReserve.

Focused on load

A key feature of the Bokpoort plant is its 9.3 hours of storage in addition to the normal 7-8 running hours during the day.

South Africa needs more generation to match the national demand profile, which has a peak between 18:00 and 21:00 in summer and winter.

“Traditional renewable plants were found a bit wanting in this area as they cannot guarantee dispatchable load over these periods,” Bhula said.

“CSP plants with sufficient storage can actually become baseload operators,” Bhula said.

For this reason, CSP in South Africa’s technology mix is vital, he said.

Bhula predicts prices for CSP with thermal storage will continue to drop and the technology can contribute to local industry as it becomes more competitive in the baseload generation space.

If Bokpoort proves its value in the South African market, this should attract more interest in the technology and more foreign investments, which in turn would result in lower construction costs.

“[Bokpoort] is a small project, but I think it has the potential to revolutionize the way people think about CSP with thermal storage,” Bhula said.