The 100-megawatt Redstone Concentrated Solar Thermal Power Project, jointly constructed by China and South Africa, is one of the largest renewable energy investment projects in South Africa. Before the project can be rolled out, it's down to chief engineer Xie Yanjun and local engineer Clayton Michael Raad to carry out the chemical water commissioning test that guarantees the plant's safe operation. By sharing green technology and expertise, China is helping drive South Africa's low-carbon energy transition, providing a firm foundation for the country's sustainable development and ecological protection.