Energy

A hybrid wind and solar plant could power a new zinc mine.

Photo: ACWA Power

Renewable energy is cleaner and rapidly becoming cheaper than conventional power, but security of supply is still a problem. Getting a reliable power supply to a remote mining destination in the Northern Cape presents its own challenges, and this makes the collaboration between Orion Minerals and juwi

Renewable Energies particularly interesting. The suggested solution is a hybrid system combing wind and solar energy. The juwi Group has experience with hybrid systems, having delivered a 10.6MW solar hybrid system to a mine in Australia, which integrated with an existing 19MW diesel-fired power plant.

The study will look into supplying the Prieska Zinc Copper

Project with 35MW of electricity from a site less than 20km from the mine, therefore allowing for a dedicated feed via overhead power transmission lines. The energy company reports that the region already has 190MW of solar power plants in operation and 240MW of wind power under construction adjacent to the project.

After a lengthy planning period and many years after it was first announced, the giant solar park that national utility Eskom wanted to build in the Northern Cape has been cancelled. The concentrating solar power (CSP) plant would have generated 100MW. Eskom’s debts make any large expenditure risky, although it is also true that the company’s reliance on coal is itself a risky calculation.

A Renewable Energy Directorate is to be established by the Provincial Government of the Northern Cape. The brief of the directorate is to assist local and district municipalities to create revenue streams related to renewable energy. Concern has been expressed at provincial government level that developers of wind and solar projects are not doing as much as they could in terms of developing local skills

Sector Insight Eskom has scrapped its solar park plan.

and employing local people in good jobs.

Industry associations claim that benefits are indeed being shared with local communities. Figures released by the South African Wind Energy Association (SAWEA) showed shareholding for local communities reached an estimated net income of R29.2-billion for projects initiated nationally since 2012. Some 14 000 new jobs are expected to be created, mostly in rural areas, and more than R30-billion has been spent on Black Economic Empowerment (BEE) in the construction phase.

In less than a decade, an entirely new sector has been created through legislation that invited local and foreign investors to bid for and then build renewable energy generation plants. South Africa’s National Development Plan (NDP) requires 20 000MW of renewable energy by 2030. That will be achieved mainly through the Renewable Energy Independent Power Producer Procurement Programme (REIPPPP).

The wind and solar parks now spreading over the vast spaces of the Northern Cape indicate that renewable energy has well and truly arrived. Approximately 60% of the projects so far allocated have been in the nation’s sunniest province.

Projects such as Kathu Solar Park, a concentrating solar power (CSP) project, and the Roggeveld Wind Farm are indicative of the large scale of most of the energy generation that is being rolled out.

Xina Solar One is located at Pofadder on the N14 between Upington and Springbok. The R9.4-billion project is a joint venture between Spanish energy firm Abengoa Solar, the Industrial Development Corporation (IDC), the Public Investment Corporation (PIC) and a community trust representing the local population. Kaxu Solar One is also near Pofadder but Khi Solar One is closer to Upington. All three plants use concentrated solar power (CSP) which reflects the sun’s rays during the day in to a molten salt storage system. The energy is then slowly released during the night. The 205m tower that collects the rays at the Khi Solar One site is one of the tallest structures in South Africa.

The Northern Cape is the natural home for the generation of solar power. Long-term annual direct normal irradiance (DNI) at Upington is 2 816kWh/m2, according to a survey done for Stellenbosch University by Slovakian company GeoModal Solar. South Africa’s national average is among the best in the world. Stellenbosch University’s Solar Thermal Energy Research Group has six sites monitoring irradiation levels.

The small towns of Postmasburg and Groblershoop lie between Upington and Kimberley. They are modest settlements which have ticked along in support of surrounding farmers with some diamond mining and wine cultivation. They are now the centre of some of the world’s most advanced technological innovation in concentrated solar power.

Saudi Arabian electricity group ACWA Power has won approval for the 100MW Redstone project near Postmasburg and the 50MW Bokpoort CSP plant (pictured on previous page) near Groblershoop is in operation.

Large wind projects are also winning approval in the Northern Cape. The commissioning of the 100MW De Aar Wind Power Project brings together Mulilo Renewable Energy and the China Longyuan Power Group Corporation.

Commercial operations have begun on Khobab Wind Farm and Loeriesfontein Wind Farm, collectively providing 280MW via 61 wind turbines. The projects were developed by Lekela Power, a joint venture between Actis and Mainstream Renewable Power. Noblesfontein was one of the earliest wind farms to be constructed in the Northern Cape, about 40km from Victoria West. Spanish company Gestamp Wind was an early investor.

The 147MW Roggeveld Wind Farm, which has 47 Nordex wind turbines and was developed by G7 and then taken over by Building Energy, will operate commercially in the first quarter of 2021. ■ Online Resources

IPP projects: www.ipp-projects.co.za National Energy Regulator of South Africa: www.nersa.org.za South African Photovoltaic Industry Association: www.sapvia.co.za South African Renewable Energy Council: www.sarec.org.za South African Wind Energy Association: www.sawea.org.za