At the recently concluded Intersolar Europe 2024, LONGi Solar officially introduced its latest TaiRay wafer-based M11, or 182.2 x 191.6mm size Hybrid Passivated Back Contact (HPBC) cell Hi-MO X6 Max module portfolio for the European market. The Hi-MO X6 Max series modules touted to be the industry’s new benchmark, boast an efficiency of up to 23.3% with a wide range of power classes of up to 630W. These latest offerings have multiple system-level applications.

The key features of the latest BC module series can be characterized by multiple key metrics – technological progress, reliability, and system-level advancements, says LONGi.

Technological progress

Thanks to the combined key features of TaiRay wafers and back-contact HPBC cell technology, these new models boast a high efficiency of up to 23.3%,  says the company. LONGi’s improved Recharge Czochralski (RCz) process-based TaiRay wafer sliced out from a longer silicon ingot with uniform resistivity from head to tail offers more concentrated cell efficiency distribution, yielding more high-efficiency cells. Alongside the TaiRay wafer, the high cell efficiency can be attributed to its back-contact HPBC cell’s key characteristics. Some key factors are reduced electron-hole pair recombination at passivated back contact, enhanced light absorption by moving the front contact to the back, and better performance in diffuse light conditions. Its industry-leading first-year 1% degradation coupled with an optimized temperature coefficient of -0.28%/°C ensures additional power generation at higher module operating temperature, shares LONGi.

Reliability & safety

LONGi has ensured one of the critical metrics of the end customer- the module’s long-term durability and reliability through its module design, wafer quality, and cell interconnection. The TaiRay wafer’s high mechanical bending strength is attributable to its lower susceptibility to lattice structure dislocations under external pressure. The wafer’s 16% higher tested bending strength compared to conventional wafers leads to the module’s improved microcrack resistance- one of the potential failure modes of the module. LONGi explained that in addition to enhanced mechanical properties, the single-line cell-to-cell soldering interconnection with a 48% lower cell edge stress, the probability of hidden crack formation is reduced by over 80%. The high-quality wafer and improved back-contact structure also addressed one of the critical potential module failure modes, by optimizing overall PID degradation of the module.

System-level advancements

The latest model’s system-level advancements can be attributed to the M11 wafer size-based module’s dimensions that lead to reduced transportation cost, improved 40’ HC container space utilization, and reduced balance of system (BoS) cost. These advancements are substantiated by LONGi’s internal test results – the Hi-MO X6 Max 72-cell version’s reduced transportation costs of 0.61$/kW, a 4.4% improvement in 40’ HC container utilization compared to its Hi-MO X6 older version. Whereas, the 3.57% reduction in the balance of system (BoS) cost is contributed by its enhanced power generation compared to equivalent power classes. The company explained that its HPBC cell-based module’s lower short-circuit current contributes to 9% lower system-level DC transmission loss, leading to 0.1% improved power generation in comparison to standard 210R modules.

The crux of LONGi’s latest adoption of M11 or 182.2 x 191.6mm size wafer with 262.5mm diagonal, is in its pursuit for standardization of module dimensions. Its 72-cell module has a size of 2382 × 1134mm and a 54-cell module has a size of 1800 x 1134mm, complying with industry-wide consensus on size standardization reached by 9 manufacturers and the subsequent agreement on wafer size standards reached by 6 manufacturers in July and August 2023, respectively.

Hi-MO X6 Max product portfolio

Hi-MO X6 Max Explorer series with an efficiency of up to 22.8% offers 465W and 615W modules in 54-cell and 72-cell configurations, respectively. The Hi-MO X6 Scientist model with superior aesthetics offers efficiency of up to 23.3% and power of up to 630W in 72 cell configuration, suitable for Europe’s residential and C&I segments.  For heavy dust-prone applications, the company has introduced the Hi-MO X6 Max Guardian Anti-Dust model with 630W power output and efficiency of up to 23.3%, scheduled to be commercially available from Q4 2024. Acknowledging the high demand for humid and heat-specific applications, LONGi has introduced the Hi-MO X6 Max Guardian Anti-Humidity & Heat series with a maximum power output of 625W and a module efficiency of 23.1%.

Senior Sales Manager UK & Ireland, Sean McSorley said,“The Max represents a significant upgrade to the existing back contact technology route and is yet another example of how LONGi embodies LONGi’s customer-centric approach to delivering maximum customer value.”