Spanish firms Sener and Acciona recently started construction on the 100-MW Kathu thermal solar park, a notable milestone in South Africa’s renewable-energy development program.

The $569-million project, owned by a consortium led by French electric utility Engie, was approved as part of South Africa’s renewable-energy independent power producer procurement (REIPPP) program, which is targeting generation of an additional 13,225MW of power from clean energy by 2030. According to the terms of the contract, Sener and Acciona will jointly carry out the plant’s engineering, construction management and commissioning by 2018.

According to Sener, the firm will supply the plant’s main technology, Sener's parabolic trough-2, which is supported by a molten-salt storage system that allows 4.5 hours of thermal energy storage, minimizing the impact of the intermittent nature of solar energy. The U.S. Energy Information Administration (EIA) says parabolic-trough technology—like Sener's—is equipped with a long, parabolic-shaped reflector that directs rays from the sun to a receiver pipe in the middle of the equipment’s open-plane curve, or parabola.

EIA says the collector’s angle keeps changing with the direction of the sun as it moves from east to west to ensure the rays are focused on the receiver pipe. Then, the thermal oil, which is used as the solar field heat transfer fluid, heats up as it circulates through the receiver pipes and returns to a series of heat exchangers at the parabolic trough system’s central location. High-pressure, superheated steam is generated and fed to a conventional steam turbine and generator to produce electricity.

Electricity from the plant—located in Northern Cape province, roughly 600 kilometers southwest of South Africa’s capital of Pretoria—will be sold to state-owned power utility Eskom. Previously, Sener and Acciona partnered to develop the 50-MW BokPoort solar plant, which is in operation in Upington, South Africa.

“This is an important milestone for our first concentrated solar-power project in the Engie Group,” said Bruno Bensasson, CEO of Engie. The company owns 48.5% of the project, with financing provided by a mix of debt and equity. Other South African investors partnering on the project include SIOC Community Development Trust, the bank Investec, Lereko Metier and the Public Investment Corp.

The firm estimates the project will create 1,200 jobs and reduce the volume of CO₂ emissions by six million tonnes over 20 years. South Africa’s REIPPP program has procured 6376 MW of electricity capacity and will be developed by 102 preferred bidders.