'Bigger is not always much better'

Aug 28, 2020 01:22 PM ET
  • Longi will certainly hold off on added panel output increases past the 600 W+ range until it can settle a number of key difficulties, a firm speaker informed pv magazine. Those impressive issues consist of low cell manufacturing yield, system compatibility, concerns regarding module transport, as well as hotspot-related failure dangers, along with the need for mechanical loading examinations.
'Bigger is not always much better'
Image: Longi

Chinese monocrystalline PV module supplier Longi has yet to join the race to create photovoltaic panels with power results over 600 W, despite the growing number of announcements from huge competitors such as JinkoSolar, Trina Solar, Tongwei and JA Solar.

In a current chat with pv magazine, Hongbin Fang-- Longi's director of item marketing-- described that the decision is in line with a clear method. "Our development logic is to look at every element of PV project implementation with an alternative view," he stated. "We can't locate an overall service that connects not just to ingot, wafer, cell as well as module production procedures, yet additionally to module deployment procedures, such as transportation, setup, and system assimilation."

Longi's Hi-MO 5 module for large-scale solar plants is thus far its most effective commercial offering, with a power output of 540 W. It measures 2,256 mm x 1,133 mm, with a surface of 2.56 m2. "It can meet higher-quality as well as higher performance demand of the industry and also to reduce the LCOE of a solar energy plant," Fang claimed, including that the M10 wafer-based module is enhanced for shipping as well as setup.

Fang claimed that larger PV modules are not always far better items, asserting that the firm's modules are made from M6 and M10 for better power output as well as lower balance-of-system prices, with a reasonably higher module present and voltage. "Significantly greater current may enhance the risk of hot spots and junction box failing," he said. "Bigger is not always much better."

The producer is persuaded that criteria such as module width, location and also working present for its 72c Hi-MO 5 are ideal. "By raising cell number to 78 for 585W panels with greater open circuit voltage would certainly bring minimal value to our clients," Fang stated. "Higher open circuit voltage means fewer modules per string, which would not assist to reduce racking as well as cabling expense."

He claimed increasing the bifacial module width beyond 1.3 m would certainly make a crossbeam on the backside required to keep enough mechanical stamina. Crossbeams develop shielding on module behinds as well as minimize the power generation of bifacial modules. "This will also increase the price of module bringing restricted worth to consumers," he claimed.

One more essential problem for 600 W+ modules, according to Fang, is their working current, which is usually greater than 18 ampere. However with bifacial gains of 15% it can also reach 21 ampere. "Such high existing dramatically raises the afore-mentioned threat of hot-spot and junction box failure," he stated.

A limiting factor for transport-related issues is the door elevation of the conventional 40' High Cube delivery container, which restricts the width of the modules to regarding 1.13 m, Fang kept in mind. "Because a larger item is so broad, either picture loading or existing level package is needed for fitting into 40' High Cube, which will boost micro-crack threat," he included.

The 1.3 m size of the 600 W modules-- weighing in at 35 kg, with a surface area of 2.8 square meters-- is not convenient for manual installments by 2 individuals.

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