A Unique Solar Power Plant with Two Towers and 30,000 Mirrors Built in China. The Plant in Gansu Province Produces 1.8 Billion kWh Annually and Reduces CO₂ Emissions by 1.53 Million Tons.
China has completed the construction of an innovative solar power plant featuring two towers and a field of 30,000 mirrors, located in the desert region of Gansu in the northwest of the country. This new facility is capable of generating up to 1.8 billion kWh of electricity per year—enough to supply power to approximately 170,000 homes.
A key feature of this plant is its use of concentrated solar power (CSP) technology, which incorporates thermal energy storage using molten salt. This technology enables power generation even at night, reducing reliance on traditional fossil fuel sources. The project is part of a larger renewable energy complex in the region and represents a significant step for China towards achieving carbon neutrality by 2060.
Large-Scale Project in Gansu
The new solar power plant is situated in Gansu Province—a region renowned for its vast desert spaces ideal for the development of solar and wind energy. Two towers, each standing around 200 meters tall, dominate the landscape, surrounded by a massive field of mirrors (heliostats). This is the world's first solar thermal power station designed with two concentrator towers operating on a single turbine.
The project has been implemented by the state energy corporation China Three Gorges Group, which is known for its large-scale infrastructure projects. Construction was nearly completed by the end of 2024, and the plant is now operational. The innovative dual-tower configuration is anticipated to significantly enhance efficiency and power output compared to traditional setups.
Concentrated Solar Power: Operational Principles
Unlike conventional solar power plants using photovoltaic panels, the new facility in Gansu is categorized as a concentrated solar power (CSP) plant. In these systems, solar energy is converted not directly into electricity, but first into thermal energy. Thousands of mirrors focus sunlight onto a receiver located at the top of the tower, heating a special heat transfer fluid. In this project, molten salt is used as the heat transfer fluid, capable of storing vast amounts of heat.
- The heliostatic mirrors automatically track the sun and reflect concentrated light onto the receiver at the top of the tower.
- The concentrated radiation heats the circulating heat transfer fluid—molten salt mixed—with temperatures reaching several hundreds of degrees.
- The heated molten salt is sent to a heat exchanger, where it transfers the accumulated heat to water.
- Water is converted into superheated steam, which drives a steam turbine under high pressure to generate electricity.
- Excess heat is stored in insulated tanks with molten salt, allowing continuous electricity generation in the absence of sunlight (at night or during cloudy weather).
Thus, the concentrated solar technology with thermal storage smooths out the variability inherent in renewable energy generation and makes solar energy more reliable compared to traditional sources.
Innovative Mirror System and Dual Towers
One of the main innovations of the Chinese project is the unusual configuration of the mirror field. Instead of constructing separate heliostat fields for each tower (as was done in earlier CSP projects), engineers arranged all 30,000 mirrors in concentric circles, overlapping the operating zones of both towers simultaneously. This "overlapping" scheme allows solar flux to be redirected to either of the two receivers depending on the sun's position and the system's needs.
During the day, as the sun moves across the sky, sections of the mirror field optimally positioned toward the eastern or western tower switch between them to maximize energy capture. This approach allows a single mirror to be used more effectively, maintaining generation at optimal levels from morning till evening. Furthermore, both towers operate simultaneously on a single turbine, simplifying infrastructure and reducing energy losses.
Developers estimate that this solution enhances the solar energy utilization factor by about 24% compared to traditional single-tower architectures. The high efficiency of the installation is further facilitated by the quality of the heliostats: modern mirrors have a reflectivity of approximately 94%, meaning nearly all incoming solar energy is directed toward the receiver.
- Two solar towers: Approximately 200-meter-high towers with heat receivers operate in parallel, both supplying energy to a single turbine generator.
- A single field of 30,000 mirrors: Heliostats are arranged in concentric circles and can direct beams to either tower, depending on the sun’s position.
- Focus switching: The mirror control system redistributes solar flux between the towers, ensuring consistent and efficient energy generation throughout the day.
- High reflectivity: Mirrors with reflectivity of ~94% concentrate solar energy on the receivers more effectively.
- Thermal storage using molten salt: During the day, excess heat is stored in molten salt tanks, allowing the plant to continue generating electricity at night.
Record Production and Emission Reduction
Thanks to the large-scale heliostat field and the efficient dual-tower configuration, the plant in Gansu has achieved outstanding energy production metrics. Its estimated annual generation exceeds 1.8 billion kWh of electricity, placing it among the world’s most powerful solar stations in terms of output. For context, this amount of energy is sufficient to power around 170,000 households.
The environmental impact of the new project is also significant. By replacing a portion of the generation that would have otherwise relied on fossil fuels, the plant is expected to reduce CO2 emissions by about 1.53 million tons annually. This is equivalent to preventing the combustion of hundreds of thousands of tons of coal or the corresponding volume of petroleum products each year. Thus, this new facility will help improve the environmental situation in the region and contribute to fulfilling the country’s climate commitments.
Integration into the Energy Hub
The dual-tower solar power plant in Gansu does not operate in isolation—it has become part of a vast energy hub that integrates various renewable sources. Solar photovoltaic fields and arrays of wind turbines are also deployed on the same site. The combined operation of these three technologies (solar concentrators, solar panels, and wind) allows for the mutual compensation of their respective deficiencies and delivers more stable power to the energy system.
During daylight hours, photovoltaic panels generate electricity directly from sunlight, while the CSP plant concentrates heat for later use. In windy weather, the wind turbines add to generation regardless of the time of day. Such integration makes the energy hub more resilient: for example, if clouds cover the sun, the stored heat from the CSP station and wind energy compensates, while during calm weather and at night, energy stored in molten salt comes into play. This comprehensive approach optimizes the use of infrastructure (power lines, substations) and reduces the overall cost of clean energy production.
Aiming for Carbon Neutrality
China is the largest producer and consumer of energy in the world, and the transition to low-carbon technologies is critically important for the country. China has officially set a goal to peak greenhouse gas emissions by 2030 and achieve complete carbon neutrality by 2060. To meet these targets, the country is making substantial investments in renewable energy—from solar and wind power plants to hydropower and new energy storage technologies. China is currently a leader in installed renewable energy capacity, outpacing other nations in the deployment of solar and wind stations.
The launch of the dual-tower solar power plant in Gansu is a milestone on this path. The project demonstrates the Chinese energy sector's commitment to embracing innovations aimed at reducing dependence on coal, oil, and gas. Historically, Gansu has been a region where a significant portion of electricity was generated from coal-fired power plants. Now, the focus is shifting towards clean energy. Each of these facilities not only directly reduces CO2 emissions but also paves the way for new similar projects, bringing the national energy system closer to sustainable development goals.
Prospects for Investors and the Industry
For investors and other stakeholders in the energy sector, the emergence of such projects serves as a crucial signal of a shift towards clean energy: renewable sources are becoming increasingly competitive in terms of generation volumes and reliability. The Gansu project illustrates that innovative renewable energy solutions can provide electricity to hundreds of thousands of consumers while simultaneously reducing the carbon footprint and decreasing reliance on fuel prices.
Major fuel and oil companies, including operators of oil refineries and coal generation facilities, cannot ignore these trends. Many are already diversifying their businesses by investing in solar, wind, and other forms of alternative energy. Projects like the dual-tower solar power plant enhance market confidence in renewable energy technologies. Looking ahead, the growing share of renewable energy in the energy balance will impact the demand for oil, gas, and petroleum products, making participation in the energy transition strategically important for players in the energy sector.
