Longi unveils Hi-MO X12 back-contact modules up to 690 W with a conductive backsheet
Victoria Shinder1 min readLongi presented its Hi-MO X12 series of back-contact solar modules at All Energy Australia 2026 in Melbourne on 28 and 29 October, pv magazine reported on 2 November. The modules are aimed at residential and commercial and industrial rooftops and use the company's hybrid passivated back contact (HPBC) 2.0 cells.
The main change is the interconnection. Instead of soldered ribbons, the cells connect directly to an integrated conductive backsheet with metal foil circuits embedded in the rear encapsulation. Longi says this removes more than 15,000 potential solder-joint failure points per module and increases the current-carrying cross-section by 85%, worth 6 W to 8 W. A second feature, which Longi calls Full-Screen Technology, combines shingled cells with hidden busbars to cut inactive area and front shading, for another 8 W to 12 W by the manufacturer's account.
The larger LR7-72WVD module for commercial roofs is rated from 660 W to 690 W with a maximum efficiency above 25.54%, according to Longi. The smaller 108-cell LR7-54WVD comes in four classes from 495 W to 510 W at 24.25% to 24.99%; its datasheet lists 1,800 by 1,134 by 30 mm, 23.5 kg, a temperature coefficient of -0.26% per degree, a 1,500 V maximum system voltage and hail resistance to 25 mm stones at 23 m/s.
What it means
The power figures are the manufacturer's claims; the more interesting claim is about failure modes. Longi's argument is that fewer solder joints mean fewer points that can fail, so if the backsheet design holds up, its value shows in years of output rather than in the nameplate watts, and that will only be visible in independent reliability testing.