How to Identify High-Quality Monocrystalline PV Modules

To identify high-quality monocrystalline PV modules, check silicon purity (≤10¹⁶ atoms/cm³ oxygen content), EVA crosslinking degree (≥85%), PID resistance (≤5% attenuation in 96h at 85°C/85% humidity), and hot spot tolerance (≤170°C under STC conditions). Use EL testing to detect microcracks.

Key Material and Manufacturing Standards

Let me start with a scary statistic - last year, a second-tier manufacturer's silicon wafers were found to have an impurity concentration exceeding the standard of 47ppm, causing the power of the components to decay by 22% within three years, directly compensating farmers for more than $420,000. This incident made me understand that the purity of silicon materials must be determined by the oxygen content. The oxygen atom concentration of top-grade monocrystalline silicon must be reduced to below 10¹⁶ atoms/cm³. If measured by a secondary ion mass spectrometer, if it exceeds this number, photoinduced decay can increase power generation by 5%. A local boss bought a batch of silicon wafers with an oxygen content of 18×10¹⁶, and six months after installation, snowflake-like white spots appeared—later testing found that oxygen precipitation caused lattice distortion.

The cutting process is even more tricky. In 2020, TÜV Rheinland found that the fragmentation rate of silicon wafers cut with 180μm + diamond wire was 63% lower than traditional processes, but the cost was $0.017 more per watt. I compared two suppliers: Factory A used 120μm fine wire cutting, and the silicon wafer surface roughness Ra was ≤0.2μm; Factory B used 80μm wire hard cutting, and the roughness soared to 0.8μm—after the latter was made into a module, dust accumulation was 40% higher, and cleaning frequency had to increase from once a month to twice a week. A photovoltaic poverty alleviation project chose Factory B for its low price, but its three-year operation and maintenance cost exceeded the initial purchase price by 18%.

The tricks of backplane materials are another issue. Last year, a power station in Shandong experienced PET backplane cracking after only two years. Inspection revealed that the thickness of the UV barrier layer was below the standard—22μm instead of the required 35μm. Simulating five years of exposure in a UV aging box, the light transmittance of ordinary backplanes dropped to 82%, while DuPont Tedlar maintained 94%. Some manufacturers add 30% recycled materials to fluorine film, lowering its softening point—genuine fluorine film softens at 327°C, while the adulterated version deforms at 285°C.

A 0.1mm reduction in solder strip width makes a huge difference. In 2021, a TOP10 manufacturer was exposed for cutting the cross-sectional area of solder strips by 15%, increasing system resistance by 0.03Ω. Over 10 years, this power loss is equivalent to installing 8 fewer panels. Now the industry standard requires tinned copper strips to be ≥0.28mm thick, with a tin layer thickness of 20-40μm. I once weighed a qualified solder strip at 4.2g/m, while an inferior one was 3.5g/m. Opening the cross-section revealed the copper core was 0.15mm thinner.

The degree of crosslinking in EVA film determines longevity. Last year, a batch of five-year-old components at the Northwest Wind Farm showed yellowing and cracking when the crosslinking degree was only 65%, while those with a degree above 85% remained intact. Using a thermogravimetric analyzer, it was found that the genuine film lost only 5% weight at 380℃, while the inferior product collapsed at 320℃. Some manufacturers mix 5% POE into EVA to increase transmittance, but under wet heat tests, delamination occurs, and PID attenuation reaches 12%—three times the normal rate.

The hardness of frame aluminum is often tampered with. After Typhoon Meihua in 2022, the integrity rate of components using 6063-T5 aluminum alloy was 98%, while those using recycled aluminum bent at a rate of 37%. Using a Webster hardness tester, the hardness of new aluminum measured ≥12HW, while recycled aluminum was only 8HW. Measuring a nominal 2.0mm frame with a vernier caliper, it was actually 1.72mm—reducing wind pressure resistance from 2400Pa to 1600Pa, making it vulnerable to salt spray corrosion.

Junction box heat dissipation is a serious issue. Last year, a listed company's components caught fire due to heat dissipation area being 26% smaller than designed, causing the operating temperature to soar from 75℃ to 112℃. Now, regulations require diode junction temperatures ≤148℃ and a thermal resistance coefficient of ≤2.5℃/W. I compared two junction boxes: Type A, using 0.8mm copper sheet + ceramic substrate, had an 18℃ lower temperature rise than Type B, which used an aluminum substrate. Some manufacturers even add 40% calcium carbonate to the box cover—burning genuine PA66 emits white smoke, while adulterated versions drip black oil.

Finally, let’s talk about glass transmittance. The nominal transmittance of 3.2mm coated glass is 93.5%, but real-world measurements show reflection losses increase by 7% when the panel angle exceeds 60°. However, 2.5mm velvet-treated glass improves annual power generation by 3.8%. Some manufacturers claim iron content is 0.02%, but spectrometer tests reveal 0.035%—raising panel operating temperatures by 5°C, which worsens power loss due to temperature coefficients (-0.35%/°C).

Process analysis

Do you know what will happen if you use 1 second less in the silicon wafer cleaning process? In 2021, a large factory cut the pickling time from 600 seconds to 550 seconds. As a result, the surface metal impurities remained 13ppm more, causing the efficiency of the cell to drop by 0.3%—based on a 100MW power station, this is equivalent to generating 540,000 kWh less electricity per year. Now the top production lines all use a triple combination of SC1+SC2+ozone cleaning. The temperature must be controlled at 65±2℃, and if the hydrofluoric acid concentration error exceeds 0.5%, the surface texturing will fail. Once, when visiting a workshop, I found that workers almost skipped the megasonic cleaning. As a result, the EL test showed that the dark piece proportion soared to 7%, and the entire batch was scrapped.

The temperature curve of diffusion junction making is a metaphysics. Last year, the industry revealed that a manufacturer secretly reduced the phosphorus diffusion temperature from 830℃ to 805℃, and the junction depth was reduced from 0.35μm to 0.28μm—it looked fine on the IV curve, but three years later, the PID attenuation reached 18%, four times higher than the normal value. TÜV SÜD conducted a comparative experiment: the efficiency retention rate of the cells made by the 835℃/25-minute process was 97.2% after five years, while the 810℃ process group only retained 89.7%. Some manufacturers even mixed recycling boats in the quartz tube, causing the square resistance to fluctuate by ±5Ω/□, and the power dispersion of the entire batch soared to 4.8%.

The thickness error of the coating process can be fatal. In 2022, a leading factory was exposed for having uneven thickness of PECVD silicon nitride film—the design value was 80nm, but the actual range fluctuated between 72-88nm, causing a 12% drop in power generation under low morning radiation. Using an ellipsometer, it was found that the reflectivity changed by 1.8% for every 5nm deviation from the standard. Once, an operator was seen adjusting the RF power from 3800W to 4000W, resulting in film layer stress exceeding standards, leading to cracking and delamination after three months—the EL image resembled a starry sky.

The accuracy of screen printing grid lines determines life and death. Last year, a manufacturer reduced the main grid count from 12 to 9, and the fine grid width from 35μm to 28μm—seemingly saving 8% of silver paste costs, but series resistance increased by 0.15Ω·cm², and the fill factor dropped by 2.3%. Using a 3D microscope, the grid line aspect ratio must be ≥0.3, and the breakpoint rate after sintering must be <0.1/piece. In a batch of goods, back field printing was offset by 0.2mm, causing the power distribution of 72 components to shift from normal to bimodal—the highest and lowest values differed by 21W, making series connection impossible.

The temperature control of the lamination process is an invisible battlefield. In 2023, a CPVT inspection found that some manufacturers reduced the EVA cross-linking temperature from 148℃ to 142℃, and shortened the time by 2 minutes—the cross-linking degree plummeted from 85% to 63%, and the delamination area reached 17% after a wet heat aging test. Differential scanning calorimetry monitoring found that temperature fluctuations exceeding ±1.5℃ caused film casting speed anomalies. Even worse, a production line secretly adjusted the vacuum degree of the laminator from -95kPa to -85kPa, increasing bubble formation by 5 times. After two years of outdoor exposure, the cell fragmentation rate reached 3.2%.

The accuracy of laser scribing directly affects microcracks. To increase production, a manufacturer raised the pulse frequency from 80kHz to 100kHz, expanding the heat-affected zone by 15μm—EL testing showed that the hidden crack rate soared from 0.3% to 2.1%. Using confocal microscopy, the qualified scratch depth should be 1/3±5μm of the silicon wafer thickness, and the edge taper angle must be 30°±2°. Once, I saw an operator increase the spot diameter by 0.2mm, causing the cutting path width to exceed the standard, forcing the cell layout spacing to increase by 1mm, leading to a 2.3% increase in glass consumption.

Finally, let me say something counterintuitive—the irradiance compensation during IV testing must be accurate to ±15W/m². During the acceptance inspection of a power station last year, it was found that the power measured by the manufacturer under 800W/m² was 4.7% less under the actual 1000W/m² conditions. Later, it was found that the temperature coefficient compensation algorithm was fake—they falsely marked the value as -0.28%/℃, but the actual component power at 75℃ was 6.3% lower than its nominal value. Now, top laboratories use dual-light source solar simulators, and spectral matching must reach Class A (±25%)—otherwise, it's like using a weight scale to measure height, making all data unreliable.

Parameters

Do you think high conversion efficiency is the key? In 2022, a manufacturer claimed a 24.5% efficiency in the lab, but mass production yielded only 22.8%. Outdoor tests later revealed that the temperature coefficient was falsely marked—the nominal -0.35%/℃ turned out to be -0.41%/℃, causing 7.3% lower power generation at noon in summer than competitors. Now, top-tier components must maintain an operating temperature of 45±3℃. For every 1℃ increase, power per watt drops by $0.005. A ground power station test showed that Longi Hi-MO 7 lost only 8.2% power at 45℃, while second-tier brands lost 14.7%—over ten years, this electricity loss could fund half a new power station.

The power tolerance issue can be deceptive. Last year, a manufacturer quietly changed the positive tolerance from 0~+5W to -3~+5W, causing 23% of modules in that batch to produce less power than their nominal values. Using an EL detector, the power dispersion of qualified cells must be ≤2.5%, while inferior ones can differ by 8%—mixing such uneven modules in the same string is like forcing a crippled runner to compete with Bolt, dragging the overall output down by more than 12%. Always demand a full IV curve inspection report and reject any batch where peak power fluctuation exceeds ±1.5%.

The annual attenuation rate is often misleading. A manufacturer claimed a 1% first-year attenuation, but Qinghai power station recorded a 0.8% drop within three months—later, it was found that they had altered the test conditions from 25℃ to 20℃, making their data seem 0.3% better. Premium products now promise ≤0.5% attenuation in year one, ≤0.45% in year two, and a 30-year linear warranty ensuring ≤16% degradation. A tear-down analysis of 10-year-old panels revealed that top-brand backplanes still had 91.2% transmittance, whereas OEM ones had fallen to 78.4%, with actual annual attenuation reaching 1.8%—turning expensive solar panels into scrap.

The PID effect (potential-induced attenuation) is a hidden killer. In a 2021 offshore PV project, power loss reached 22% within three months due to salt spray exposure. Tests showed that at system voltages above 1500V, the PID failure rate soared to 37%. Now, qualified modules must survive 85℃/85% humidity for 96 hours, with ≤5% degradation. One counterexample: A manufacturer using ordinary EVA film saw efficiency drop 18% after PID testing, while another using anti-PID film + advanced packaging controlled degradation to 2.3%—this difference extended the payback period by 2.8 years.

Low-light performance is crucial for real revenue. At 6 AM, under 200W/m² irradiance, a second-tier brand’s efficiency plummeted to 9.7%, while Trina Solar's Supreme Series maintained 17.3%. In rainy areas like Jiangsu, Zhejiang, and Shanghai, this can mean 15% more annual power. Using a spectral response tester, top-tier modules achieve ≥85% quantum efficiency in the 300-500nm wavelength range—otherwise, performance on hazy days will fluctuate like a roller coaster. A real-world comparison showed that high-efficiency modules earned $3.20/MW more daily, adding up to a free Tesla in one year.

Load capacity directly impacts system reliability. During a typhoon, a power station’s string current spiked to 14.2A, and a low-grade inverter burned out. The root cause? The module’s nominal max current was 13A, but actual performance tests showed 12.3A hotspots. Reliable modules now require 1.25x overload tolerance for 2 hours, and junction box temperatures must stay ≤85℃. Some manufacturers falsely claim 1500V system voltage tolerance, yet leakage current alarms start at 1380V—deploying such subpar products in utility-scale plants is a disaster waiting to happen.

Certification Standards

You shall not think that you can rest easy once you get an IEC 61215 certification. In 2023, TÜV found that one certified module from an individual manufacturer lasted only 72 hours in the double 85 test (85℃/85% humidity), far below the 1,000-hour standard. After two years of operation at the Hainan power station, for example, the backplane delamination rate reached 19%, and power attenuation was 3.7 times higher than the standard. Now, fire-resistant components must resist the more severe tests under IEC TS 63209, including -40℃ hail impact and 5,400Pa mechanical load. Products passing this test have a five-year failure rate 68% lower compared to ordinary certified components.

UL 61730 fire rating conceals bitter lessons. In the 2021 California wildfire, there was an OEM module that used substandard materials in the Class C fire test and accelerated the fire spread by 47 seconds per square meter, which destroyed the power station and caused a $23 million loss. Now, high-end products must have Class A fireproof certification, that is, the flame spread index ≤ 25 and smoke density index ≤ 50. One of the most important tests is to measure the material heat release using an oxygen bomb calorimeter; a qualified backplane must be ≤ 18MJ/ kg, while poor-quality PET materials can go up to 28MJ/kg and turn into gasoline upon exposure to fire.

The Tricks of Salt Spray Testing Can Corrode Profits. A coast power station once purchased modules which declared to pass IEC 61701 Level 6 anti-corrosion test, but after one year, the rust of the junction box caused failures of 14% strings. Later on, it was found out that this manufacturer cut corners by diluting the salt spray concentration from 5% NaCl to 3% and shorten the test time by 200 hours. The hardcore anticorrosion standard is actually: MIL-STD-810G-under the condition of less than 35℃, depositing 1.5ml/80cm²/h of salt spray for 720 hrs, the corroded area needs to be ≤0.5%. After an aquaculture-photovoltaic project in Zhejiang replaced products whose certification was qualified, O&M costs decreased 41%.

Voltage threshold of PID test is a magical mirror. A 2022 industry scandal exposed a manufacturer that used 1,500V system voltage for testing, but the actual product had a 5.8% power attenuation at 1,100V—they exploited a ±10% voltage fluctuation loophole in the standard. Now, leading manufacturers voluntarily test at 2,000V/96 hours, requiring a decay rate of ≤2%. Comparison data: after 85℃/85% humidity/192 hours, LONGi Hi-MO 6 maintained an efficiency of 98.3%, while that for an OEM product was 89.7%-a difference of 2.3 years to recover the investment.

The particle size in dust testing determines life and death. Last year, at a Xinjiang power station, modules that failed the IEC 60068-2-68 dust test suffered a 13% drop in light transmittance due to glass erosion from sandstorms. The inspection revealed that the manufacturer used ≤75μm dust particles, while real desert sand contains 32% particles ≥150μm. Now, strict certification requires Arizona Road Dust standard sand, continuous sandblasting for 8 hours at 15m/s wind speed, and a glass wear depth ≤3μm. After an Inner Mongolia project switched to certified components, annual power generation increased by 9.8%, and the cleaning frequency dropped from once per week to once per month.

The hot spot test contains a fatal trap. A second-tier module was rated for 15A reverse current tolerance, but solder strips melted at just 12A—they manipulated test results by preheating battery cells to 60℃ to reduce resistance. Now, authoritative certification requires hot spot testing to be conducted under STC conditions, with infrared thermal imaging to monitor temperature. Any area exceeding 170℃ is immediately scrapped. A fire at a Qinghai power station was later traced to hot spots in failed modules—the measured temperature reached 243℃, while the certification report falsely claimed a maximum of 158℃.

Appearance inspection

Don't think that everything is fine if the surface of the component is smooth—during the acceptance of a power station last year, a worker used a flashlight to shine diagonally and found a hidden crack with a width of 0.2mm. After disassembling it for inspection, it turned out to cause a power attenuation of 5.3%! This kind of crack will appear as black dendrite-like lines under the EL detector, usually within 3mm of the edge of the battery cell. There is a trick: use 800V voltage + 900mA current for electroluminescence detection, and the dark crack will show its original shape under blue light, which is 20 times more accurate than naked eye observation. What's more, a manufacturer mixed 0.5mm diameter bubbles during lamination, which expanded into 8cm delamination after two years of outdoor exposure, and directly scrapped the entire board.

Solder point oxidation is an invisible killer. In 2023, CPVT spot checks found that the thickness of the oxide layer on the surface of a component's solder strip reached 12μm (standard requires ≤5μm), resulting in an increase in series resistance of 0.08Ω—this is equivalent to 83 kWh less electricity per string per year. When viewed with a 30× magnifying glass, qualified solder joints should present a bright silver metallic luster, and those that are oxidized and blackened should be directly scrapped. A fishing light project in Zhejiang Province suffered a loss—the solder joints were not connected properly, causing hot spots, and the highest temperature soared to 187℃, burning the EVA film with scorch marks.

Backboard wrinkles are more deadly than imagined. Last year, a batch of components on the backboard of a wind farm in Inner Mongolia had wavy wrinkles, with a height difference of more than 1.5mm—under the action of outdoor wind vibration, the cracking rate reached 23% after three years. Industry standards stipulate that the wrinkle depth shall not be greater than 0.8mm, and the number per square meter shall be ≤3. There is a wild way to detect this: take an A4 paper and lay it flat on the backboard. The wrinkled area where the paper cannot fit completely is the detonation point for future cracking.

Frame scratches hide great risks. In 2022, a project used an aluminum frame with a 0.3mm deep scratch. As a result, the salt spray corrosion rate accelerated by 4 times. Two years later, the wall thickness of the profile was corroded from 2.0mm to 1.2mm, and the wind pressure resistance plummeted from 2,400Pa to 800Pa. Using a surface roughness meter, frames with Ra values >3.2μm are chronic suicide in coastal areas. Even more insidious is that some manufacturers falsify the thickness of the anodized film. The nominal 15μm is actually only 8μm, and it will be exposed when poked with an eddy current thickness gauge. Uneven glue filling of the junction box can be fatal. After heavy rain last year, a power station had a leakage. After disassembling it, it was found that the glue coverage rate of the junction box was only 60% (required ≥95%), and moisture intrusion caused the diode to short-circuit. Scanned with an X-ray detector, the bubble diameter of qualified glue filling must be <0.5mm and the density ≤3/cm³. The height difference of the glue filling of some batches reached 2.3mm, and the sealing ring was directly torn after thermal expansion and contraction. This kind of component will not survive more than three years in a hot and humid environment.

Scratched glass is not just a face-saving issue. A 20cm long scratch appeared on the surface of a mountain power station component. It was calculated that it caused a 7% loss in incident light scattering—equivalent to a $21 per panel loss per year. Scanning with a transmittance tester, the transmittance of the scratched area will drop sharply from 93.5% to 81.3%. What's even worse is that some manufacturers use ordinary glass to impersonate coated glass. When exposed to ultraviolet light, real coated glass will show purple-red interference fringes, while fake ones will appear dead white.

Brand comparison

Do you think the leading brands are unreasonably expensive? Disassembling Longi Hi-MO 7 found that its silicon consumption per watt is 12% lower than that of second-tier brands—a single module earns $0.11 more. Based on a 100MW power station, the material cost alone saves $110,000. But don't rush to pay. JinkoSolar Tiger Neo has a bifacial rate of 85%, which is 9% higher than similar products of Trina Solar, and its annual power generation is 7.3% higher in a snow-reflective environment. There is measured data from a Qinghai power station: the power attenuation of the bifacial modules of Longi, JinkoSolar, and Canadian Solar after five years is 2.1%, 2.8%, and 3.5% respectively—the gap is enough to buy five-year operation and maintenance insurance.

Behind the price war is the technology generation gap. A third-tier brand claims a conversion efficiency of 21.5%, but it is actually a single-chip data in the laboratory, and the average mass-produced module is only 19.8%—while the mass-produced efficiency of JA Solar DeepBlue 4.0 Pro is stable at 22.4%, costing $0.02 more per watt, but generating 5.7% more electricity per year. What's even more ruthless is that the heterojunction modules launched by Risen Energy have a power output 6% higher than PERC modules at a high temperature of 50°C, but the cost per watt is $0.04 more expensive—this account must be calculated clearly: the payback period in the southern region can be shortened by 1.8 years, while the north may lose money.

The value of certification is a magic mirror. In 2023, TÜV found that although a third-tier brand passed IEC 61215, the diameter of the ice ball used in the hail resistance test was only 25mm (the standard requires 35mm), and the damage rate in the hailstorm in Yunnan was 17 times higher than that of Longi. In contrast, First Solar’s thin-film modules, although the efficiency is only 18.6%, have passed the UL 61730 Class A fireproof certification, and the smoke toxicity when on fire is 63% lower than that of crystalline silicon modules—this is a life-saving talisman for rooftop power stations.

The devil’s details are hidden in the after-sales warranty. A third-tier brand promised a 12-year product warranty, but the terms and conditions stated "only for non-coastal areas"—when a project in Qingdao claimed compensation, it was discovered that the corrosion failure was classified as "force majeure". In contrast, Trina Solar’s worry-free warranty clearly includes compensation for salt spray corrosion, and replacement is required if the attenuation rate exceeds the tolerance. Statistics from a fishery-photovoltaic complementary project in Zhejiang: 23 repairs were reported in five years using a third-tier brand, while JinkoSolar components were only repaired twice—the difference in operation and maintenance costs was $25,000/MW.

The cost game of second-tier brands can kill people. A manufacturer reduced the frame thickness from 2.0mm to 1.6mm, saving $1.10 per component, but the wind pressure resistance dropped from 2,400Pa to 1,600Pa—after the typhoon, the repair fee was compensated at $5.50/unit. What's more, some manufacturers used 0.5mm thick copper sheets (industry standard ≥0.8mm) in the junction box, which caused poor heat dissipation and burning, and a single string failure caused a 7% power generation loss. Sungrow’s smart components come with chip-level monitoring that can warn of failures 14 days in advance—this is a technology premium that smaller manufacturers won’t be able to catch up with in a decade.

Maintenance points

Don't think that wiping the surface is enough—a power station in Qinghai cleans the components every month, but ignores the dust on the back. As a result, the gain of the back of the bifacial components plummeted from 18% to 6%, with an annual loss of $51,500/MW. The correct approach is to use pure water with a conductivity of ≤50μS/cm, combined with a 30° inclination for flushing, which can reduce the dust reflectivity from 23% to 7%. Even more ruthless is that the Gansu wind farm uses drones to spray dust-proof coatings, extending the cleaning cycle from 15 days to 45 days, and reducing operation and maintenance costs by 62%.

Hot spot detection must be played for real. In 2023, a rooftop power station in Shandong caught fire, and the hot spot temperature was found to be 198℃ after tracing the source—the infrared thermal imager they used had an accuracy of only ±5℃, and missed 3 hidden dangers. Now it is necessary to use the FLIR T840 with an accuracy of ±1℃ to scan when the irradiance is >800W/m², and immediately check areas with abnormal temperatures ≥15℃. A project in Zhejiang Province used this method to reduce the hot spot failure rate from 7% to 0.3% within three years, saving $167,000 in insurance claims.

Loose electrical connections can kill people. In 2022, the Ningxia power station suffered a 14% drop in string efficiency due to poor contact of the MC4 plug—the multimeter measured the contact resistance from 0.2Ω to 1.8Ω. Now it is required to check with a torque wrench every quarter, the DC side connector must reach 35N·m torque, and the AC terminal must reach 25N·m. There is a trick: apply power composite grease at the connection, which can delay the increase in resistance caused by oxidation by 3 times.

Anti-corrosion is not just about painting. In an offshore photovoltaic project in the Bohai Bay, the bracket without zinc block sacrificial anode protection had a three-year corrosion rate of 0.8mm/year, which is 4 times faster than that with protection. It is now mandatory to require the thickness of the galvanized layer at the grounding point in coastal areas to be ≥85μm, and to use a coating thickness gauge to detect it every six months, and to re-coat it immediately if the loss exceeds 30%. What's more, a power station in Guangdong put fluororubber sleeves on the bolts, reducing the thread corrosion failure rate from 22% to 1.1%.

Data monitoring is more reliable than people. In 2024, a smart operation and maintenance system warned of inverter failure 14 days in advance, avoiding 9 hours of downtime—based on a 10MW power station, the loss was reduced by $7,500. Now the advanced solution is to monitor the IV curve of the group string level, which can capture 0.5% of the power anomaly. A certain agricultural photovoltaic project in Jiangsu used Huawei FusionSolar system to reduce the fault location time from 3 hours to 8 minutes, and the operation and maintenance efficiency increased by 23 times.

Don't underestimate physical damage inspection. A power station in Inner Mongolia was hit by sand and stone, with a 0.3mm deep glass scratch, and the light transmittance decreased by 0.7% every month—later it was filled with polyurethane repair glue to bring the annual attenuation rate back to normal levels. Now it is necessary to equip a 200x portable microscope, sample 5% of the components every month, and replace them immediately if the crack length is >15cm. An operation and maintenance company has developed an AI crack recognition system, which has a detection efficiency 17 times higher than manual detection and reduces the missed detection rate to 0.08%.

Seasonal maintenance is a mystery. A power station in Northeast China did not adjust the bracket inclination before winter, and the snow load bent 7% of the components—in fact, adjusting the inclination from 35° to 50° can speed up the sliding of snow by 3 times. In summer, the inverter needs to be equipped with a sunscreen partition, which can reduce the internal temperature by 12°C and reduce the failure rate by 41%. The most amazing thing is that a project in Yunnan applied a hydrophobic coating before the rainy season, which increased the self-cleaning efficiency of rainwater by 28%, which is equivalent to earning 9 days of power generation for free.