Context: China has unveiled the world’s first dual-tower solar thermal power plant in Gansu Province. The plant is expected to be operational by the end of 2024.

• Solar thermal or concentrated solar power (CSP) systems rely on mirrors known as heliostats to bounce sunlight to a central gathering point.

• There, the concentrated beams heat a transfer fluid that, in turn, heats a working fluid. This fluid then evaporates, turns a turbine, and generates electricity.

Key Points

• China has unveiled the world’s first dual-tower solar thermal power plant, which utilises an innovative design to significantly improve energy efficiency.

• Unlike conventional thermal power plants, it incorporates molten salt storage to produce power at night when the sun is unavailable.

• Molten salt stored in the towers functions as a thermal battery, storing excess heat during the day and releasing it to keep the generators running continuously.

• The mirrors in the overlapping area can be utilized by either tower

• The mirrors track the sun’s movement, concentrating its rays on the eastern tower in the morning and automatically adjusting westward in the afternoon.

• The mirrors are made of special materials, whose reflection efficiency can reach a staggering 94%.

• China claims that this design is not limited to the two towers; it has the potential to involve multiple towers for even greater efficiency gains.

• The mirrors form two vast, overlapping circles focusing sunlight on each tower. Like a traditional coal plant, the concentrated sunlight heats water to generate electricity.

• Unlike conventional thermal power plants, this design incorporates molten salt storage as a thermal battery. The molten salt retains extra heat collected during the day and releases it at night, allowing the plant to generate power continuously.

Significance

• It integrates solar, thermal, and wind power to generate over 1.8 billion kilowatt-hours of electricity annually while avoiding 1.53 million tons of carbon emissions.

• The dual-tower design’s ability to boost efficiency by 24% underscores the country’s commitment to driving innovation and accelerating the clean energy transition .