China's Dual Tower CSP Innovation

China Three Gorges Corporation has announced significant progress with the world's first dual tower concentrating solar power (CSP) plant, which is now in its final commissioning phase and slated to commence electricity generation by year-end. This innovative molten salt CSP facility features twin towers towering up to 650 feet and about 30,000 mirrors designed to concentrate sunlight onto a central receiver. By heating molten salt to drive generators, it ensures uninterrupted power supply. The project's twin tower configuration and adaptable mirror array are poised to enhance solar thermal power generation efficiency and reliability. Anticipated annual output is 1.8 billion kilowatt hours, contributing to a reduction of 1.53 million tons of carbon dioxide emissions annually.

In addition, the project integrates several cutting-edge technologies. For instance, the mirror array is equipped with automatic sun-tracking capabilities throughout the day, utilizing ultra-white glass that reflects 94% of solar energy onto the receiver. This innovative setup enhances the efficiency of solar power conversion. Unlike conventional photovoltaic plants, the dual-tower design bypasses constraints on installed capacity, thereby significantly boosting both power generation and energy storage capabilities. Collaborating with nearby photovoltaic arrays and wind turbines, the new CSP system aims to advance the adoption of sustainable energy solutions.

China's Dual Tower CSP Innovation

What is CSP?

Solar energy is commonly linked to photovoltaic panels, which directly convert sunlight into electricity. However, since the early 1980s, another method for harnessing solar energy has been advancing steadily: concentrated solar power (CSP) or solar thermal energy. This technology employs heliostats to reflect sunlight onto a central collection point, where the concentrated beam heats a fluid to generate electricity.

The advancement of solar thermal power stations is expanding worldwide. In 2014, the Ivanpah solar power system in the United States became one of the largest solar thermal power plants globally, boasting a capacity of 392 megawatts. However, Australia's attempt to build the world's largest single tower solar thermal power plant project was halted in 2019. Meanwhile, Morocco's Noor Complex solar power plant currently holds the title as the world's largest solar thermal power plant, capable of generating 510 megawatts of electricity.

Noor Complex solar power plant

The CSP project introduced by China Three Gorges Corporation exhibits similarities with American counterparts but distinguishes itself through its unique technological configuration. China's initiative in solar thermal energy storage utilizes multiple towers, with two of them sharing a common turbine. This design optimizes the efficiency of solar thermal power generation by strategically positioning mirrors in overlapping concentric circles to maximize sunlight reflection.

How can solar energy be utilized after sunset?

Beneath the towering heat absorption tower are two large storage tanks containing molten salt, which has a high boiling point of 600°C—much higher than water's 100°C. This liquid molten salt can store significantly more heat than water. During daylight hours, solar energy collected by the heat absorption tower is converted into thermal energy and stored in the molten salt, ensuring continuous and reliable power output day and night.

Storage tank for molten salt

As of now, the two towers of the upcoming power station are nearing completion, with 90% of the construction finished. The project aims to utilize molten salt for storing heat during the day and releasing it at night, ensuring stable and reliable power generation capability. Expected to begin operations later this year, the new CSP system will work alongside nearby photovoltaic panels and wind turbines to promote advancements in clean energy initiatives.

The progression of CSP technology is set to reduce reliance on traditional fossil fuels and hasten the global transition to sustainable energy sources. As technological advancements continue and applications broaden, solar thermal power plants are expected to assume a crucial role in the global energy scenario, providing vital solutions to address climate change and bolster energy security.