When the vast Gobi Desert meets the boundless sunlight,thousands of silver mirrors unfold in sequence, precisely tracking the sun,painting the most moving green landscape of the great northwest.
On October 1, CCTV-4's program "Traveling Across China" presented its National Day special "Beloved China," visiting CGN's Qinghai Delingha 200 MW tower-type concentrated solar power (CSP) project. The program revealed the story behind this desert solar plant — a special group of energy guardians who, with meticulous craftsmanship, maintain tens of thousands of sun-tracking mirrors, converting boundless sunlight into light for millions of homes.
In many people's eyes, the vast mirror field is crystal-clear and magnificent. But for the operations and maintenance staff of CGN's Delingha 200 MW tower CSP project, this 640,000-square-meter silver "flower sea" is a demanding and meticulous "super-sized household chore."
The mirror field is home to 21,534 heliostats, covering a total area equivalent to 90 standard football fields. Each mirror is a 30-square-meter light-collecting unit, shouldering the core mission of capturing sunlight and concentrating thermal energy. Like faithful sun-followers, they track the sun's trajectory at all times, precisely focusing scattered sunlight onto the central receiver tower.
The receiver tower, shaped like a giant "thermos flask," stores abundant solar heat during the day and continuously converts it into clean electricity around the clock, enabling stable, uninterrupted power generation. Whether this top-tier CSP system can operate efficiently at full capacity depends critically on the cleanliness of the tens of thousands of mirrors.
"When the mirrors are dirty, less light reaches the tower, and the heat output drops. The power difference between clean and dirty mirrors can be as much as one-third," said Tang Dongyu, an operator at the Delingha 200 MW tower CSP project, highlighting the key to this "household chore." What seems like simple mirror cleaning is in fact the first line of defense for green power output — there is no room for carelessness.
Unlike everyday household cleaning, maintaining a giant CSP mirror field is a dual test of physical strength and precision. A single mirror measures 6.2 meters long and 4.8 meters wide — more spacious than an ordinary living room. It must not be scratched or bumped during cleaning, and the work must be done quickly without interrupting power generation — a task beyond human efficiency.
To this end, the project is equipped with an intelligent cleaning vehicle developed in China, serving as the mirror field's dedicated "super cleaner," precisely tackling the challenge of mirror cleaning. The intelligent cleaning vehicle can wash 2,155 mirrors per day, completing full coverage of the entire mirror field in just ten days, efficiently matching the plant's operation rhythm.
The cleaning process showcases clever engineering: a robotic arm precisely adjusts its angle, simulating a "bowing to wash the face" posture to fit the mirror surface. It also uses specially purified water, completely eliminating water stains left by ordinary water, ensuring mirror cleanliness on all fronts — so that every beam of sunlight can be concentrated without loss and used efficiently.
Polishing the mirrors is only the foundation; precise light control and intelligent operation are the true core strengths of this super CSP plant. In the past, core equipment for CSP plants was highly dependent on imports — not only expensive, but also poorly adaptable, with maintenance and modifications restricted, leaving China constrained at every turn. Upholding the original aspiration of independent innovation and self-reliance, the CGN team delved into CSP technology development, achieving full localization of core equipment including heliostats, sun-tracking systems, and the receiver tower. From equipment manufacturing and fault repair to process optimization and system commissioning, everything is independently controlled.
On top of this hardcore domestically produced hardware sits a smart "housekeeper brain" that coordinates the entire plant. In the project's main control room, an intelligent operation and maintenance system monitors the status of all equipment in real time, precisely coordinating mirror angle adjustment, equipment start-up and shutdown, and mirror cleaning schedules.
Tens of thousands of heliostats fine-tune their angles every second, with error strictly controlled within 0.114 degrees, maintaining the optimal focusing angle with the sun around the clock. This extreme precision ensures the stable operation of the concentrating and heat collection system, maximizing the conversion of every ray of sunlight into clean electricity. From meteorological monitoring and system preheating to concentrated power generation and energy storage release, the entire process is intelligently controlled, precise and efficient.
Meticulous operations, hardcore independent innovation, and intelligent system management allow CGN's Delingha tower CSP project to unleash powerful green energy. Leveraging the stable energy storage advantages of CSP, the project effectively compensates for the intermittency of renewable generation and offers excellent grid peak-shaving capability. It can steadily produce 263.88 million kWh of green electricity annually, meeting the electricity needs of more than 70,000 households for an entire year — lighting up countless homes with a continuous stream of clean power.