On July 16, CGN officially unveiled "Yuanyao I", the world's first molten-salt parabolic trough solar collector with an 8.6-meter aperture, in Xining, Qinghai Province. The model marks an important advance in solar-to-electricity conversion efficiency and full-chain self-reliance, providing core technical support for the large-scale development of China's concentrated solar power industry.

"'Yuanyao I' uses an 8.6 m large-aperture design. Four collectors form a single 732 m loop with a collector area of 5,970 square meters, equivalent to the combined area of 14 standard basketball courts. Compared with conventional heat-transfer-oil trough collectors with a 5.7 m aperture, its collector area per loop is about 83% greater, while its land footprint is 19% smaller," said Yin Hang, CGN's Chief Expert for Concentrated Solar Power Technology. With the same solar-field area, 'Yuanyao I' requires substantially less piping, fewer valves, and fewer local control systems, effectively reducing life-cycle costs for assembly, installation, commissioning, and maintenance.

To fully validate the model's performance limits, CGN built China's first standardized 8.6-meter-aperture molten-salt trough pilot loop in Delingha, Qinghai, and has completed full-condition process and performance testing on three representative weather days—winter solstice, spring equinox and summer solstice. A third-party laboratory accredited by the China National Accreditation Service for Conformity Assessment (CNAS) measured that the collector's thermal efficiency can reach over 70%. For the Delingha region, the converted annual average solar-thermal efficiency reached above 38% and an annual average solar-electricity conversion efficiency above 17% and it can keep stable operation at the temperatures as low as minus 23 degrees Celsius and in force-9 winds. An expert evaluation rated the complete molten-salt trough collector technology as internationally leading level.

"The model uses solar salt as the heat-transfer and storage medium, operating between 290 and 565 degrees Celsius. The strong temperature control capability of parabolic trough technology can keep the molten salt from ever overheating or degrading to extend the equipment's service life," said Wang Qiang, Director of the Operation Control Research Institute at CGN Solar Thermal Technology (Beijing) Co., Ltd. He noted that China's solar resource regions typically face highly variable irradiance, frequent high winds and low air cleanliness. The team spent three years addressing these challenges to complete the model, and the core parameters unveiled carry high industry value and it will be upgraded based on market feedback.

"Through systematic research spanning optics, thermodynamics, coordinated structural design, domestic development of key components, loop-level pilot validation and a full-process performance testing system, CGN built 'Yuanyao I' and, with it, a complete technical system covering design, manufacturing, installation, inspection, and operation and maintenance has been established," said Yang Hairui, professor at Tsinghua University's Department of Energy and Power Engineering. He noted that the project has secured 13 invention patents and reached an internationally advanced level overall and the collector's surface-shape inspection system is also rated internationally leading by scientific and technological achievement evaluation.

"To ensure the collector's optical performance, we first set the ambitious target of keeping surface-shape accuracy within 2 milliradians. We then developed dedicated high-precision assembly tooling, overcoming the challenge of precisely assembling oversized components 8.6 m wide and 18 m long. This kept "Yuanyao I"  overall assembly deviation strictly within 2 mm and achieved the intended target, improving precision by 20% compared with collectors with a 5.7 m aperture," said Zhang Ji, Director of the Concentrated Solar Collection Research Institute at CGN Solar Thermal Technology (Beijing) Co., Ltd.

To hold the surface-shape accuracy, CGN developed China's first collector surface-shape inspection system, measuring to within 0.2 millimeters, which is about the thickness of two sheets of A4 paper stacked together. The collector's control system tracks to within 1 milliradian and integrates intelligent functions for preheating, temperature control, overtemperature protection and high-wind protection, improving safety while easing the load on operators. For environmental resilience, the model's space-truss structure withstands force-12 winds, and a single-section flexible molten-salt connection eliminates the end-of-collector deformation that traditional rotary-joint compensation produces, cutting both construction difficulty and cost.

CGN also worked with companies across the supply chain to achieve 100% domestic production of components such as collector tubes and mirrors, and rolled out a full suite of technical solutions covering preheating, salt filling, commissioning, anti-freezing, thawing and maintenance, supporting the project across its entire life cycle.

In December 2025, the National Development and Reform Commission (NDRC) and the National Energy Administration (NEA) set a target for China's total installed concentrated solar power capacity to reach around 15 million kilowatts by 2030. Yang Kun, Executive Vice Chairman of the China Electricity Council, said the industry is entering a fast-growth phase under the 15th Five-Year Plan, and that "Yuanyao I" would help drive down costs and scale up the sector.

Hu Guangyao, Secretary of the Party Committee and Chairman of CGN New Energy, pointed out that "Yuanyao I" has outstanding features of strong resource adaptability, efficient operation and maintenance, high modularity and broad range of applications. Cost will be further reduced with the industry scales up. CGN's 350-megawatt Golmud concentrated solar power demonstration project has already broken ground, using a tower-trough hybrid molten-salt route that will bring "Yuanyao I" to large-scale application and has become a flagship for the model's wider rollout.