. From module design, through mass production to post-sales support, LONGi adheres to its core concept of ‘Customer Value First' and ensures that quality practices are incorporated at every stage of production and application.
Reliable technology: multiple assurances in innovation, management and customer values
The LONGi Lifecycle Quality concept was created from a blank canvas. Adhering to an innovative concept based on reliability, LONGi aims to rapidly transform its technological innovations into large-scale production capacity, further reducing LCOE. With this objective in mind, the company’s R&D team has re-doubled the efforts which have enabled LONGi to consecutively break industry world records, with a view to the company’s lifecycle quality concept becoming the benchmark for the PV industry.
- First-class R&D Centre
LONGi's Product R&D Centre has been carrying out in-depth cooperative research with scientific institutions such as the University of New South Wales, Sun Yat-sen University and the China Electric Institute (CEI). In terms of raw material testing, the company owns the first exclusive testing centre in the industry, the specific laboratory having been approved by the China National Accreditation Service for Conformity Assessment (CNAS), and its reliability testing centre is in strategic cooperation with multiple international certification bodies including TÜV Rheinland, TÜV SÜD, TÜV NORD, CGC and CSA.
- Multi-dimensional analysis of module design
In the discipline of module design, LONGi integrates theoretical models with experimental results and takes into account power output, efficiency, power generation and reliability under various scenarios. Specifically, the company carries out product development under the six ‘pillars’ of high optical utilization, reasonable electrical design, high encapsulation density, low degradation, stable supply chain guarantee and transportation compatibility. The optical, electrical and mechanical models related to module design are established at an early stage, with simulation calculation carried out simultaneously to select the optimal solution.
As shown in the figure above, through testing of raw materials, external applications and different installation methods, LONGi defines optimal module and silicon wafer size for its Hi-MO 5 (182mm silicon wafer-based) product.
- Thresher tests carried out to eliminate potential risks
By adopting differentiated test methods under different application scenarios and extreme climatic conditions during module design, it is possible to effectively monitor both products and materials to ensure their suitability and reliability in challenging environments. In addition to 2 & 3 times IEC thresher testing for end products, HATC, DH & UV aging tests, all above industry standards, will be carried out in order for module quality to meet installation and usage requirements when confronted with extreme conditions.
LONGi is also at the forefront of wind tunnel testing to validate the design of its modules, which are subjected to a maximum wind speed of 60m/s, equivalent to a 17 magnitude hurricane. In hail test, LONGi goes as far as enlarging the size of hailstones to more than 35mm to ensure that a module is capable of resisting catastrophic weather.
Reliable material introduction: stringent testing conducted to select the best
In terms of management standards, LONGi applies the most stringent criteria to BOM, reliability monitoring and the material introduction process. For raw materials such as glass, ribbon, EVA, backsheets, frames and junction boxes, etc., only those suppliers meeting the LONGi BOM standards can be considered. Only those that pass this rigorous testing process can be introduced into mass production. In this way, LONGi has referred to industrial criteria of 824 items, taking the reliability of LONGi’s standard BOM to a new level.
On the basis of superior product design and material introduction, LONGi was awarded ‘High Achiever' status by RETC for the third consecutive year for its thresher testing of products (i.e. three times the IEC standard) and receive top marks in all nine categories. It was also rated as a ‘Top Performer' by PVEL for the fifth consecutive year, achieve this ranking in all six available categories.
The extreme nature of product and material testing is in order to achieve the highest standards of reliability. Selection of reliable materials is the cornerstone of module quality for PV manufacturers and, going forward, LONGi commits to there being no compromises on materials or quality standards in order to increase power or reduce costs.
Reliable manufacturing: comprehensive quality control ensuring lean manufacturing
Quality control systems, including ISO9001, ISO45001, ISO14000 and IEC TS 62941, are observed to comprehensively control LONGi’s manufacturing quality. The company has also established a comprehensive quality control system covering raw material control, manufacturing process and end-product reliability monitoring. Specifically, LONGi has introduced several advanced digital management platforms that are present throughout the whole quality control process, making the implementation and traceability of management standards more efficient and transparent. With LONGi module factories being based around the world, the process has allowed consistent control of materials, quality and testing standards to ensure that all modules are manufactured to the same standard and quality, regardless of location.
In LONGi's automated and intelligent workshops, by delicacy management, there are 22 manufacturing procedures, 153 items under quality inspection to ensure standardization of the production process, ensuring that every module produced by the company is of the same excellent quality.
LONGi conducts comprehensive annual, quarterly and monthly product performance monitoring. For example, a high-frequency monitoring approach is applied for monthly tests, such as PID, LID and LETID, covering all product models and each set of BOM. Hail test, salt mist, fire protection.
To protect the rights and interests of its customers, LONGi adopts digital methods to handle the anti-counterfeiting validation of each module and has also set up post-sales services. To solve global customers’ problems in a timely fashion, LONGi has set up over 10 marketing and service centers in its global core markets to provide a local service 24/7. LONGi not only responds to its customers’ needs in a timely manner during the after-sales phase but, at the very beginning of business communication, the company also provides efficient and professional advice in terms of product selection, cooperation planning, business support, logistics and transportation.