If there are two new innovations that are threatening to take over the PV module market, they are half-cut cells and bifacial cells and modules. LONGi, arguably the most innovative of large Chinese PV makers, has for some time been putting out products that combine both of these innovations in a single module through its Hi-MO series.

Today at Intersolar Europe LONGi unveiled the latest and most powerful module in this series to date, the Hi-MO 4. The new module offers efficiencies of 18.5-19.2%, with power ratings up to 430 watts, which LONGi credits to upgrades in its Passivated Emitter and Rear Cell (PERC) technology.

Of course, this is not counting the gain from the back side, which is expressed not in watts but in energy output. And while there is still a lack of standardized systems for measuring this across the industry, LONGi claims an 8-20% gain from its bifacial modules.

LONGi has been a champion of bifacial and has manufactured and deployed more than anyone known to pv magazine, with an estimated 1.5 GW deployed to date.

Higher power, lower BOS costs

In terms of efficiencies, Hi-MO 4 is a modest improvement on LONGi’s Hi-MO 3 series launched in 2018, which offered efficiencies from 17.9-19.1% and, like the Hi-MO 4, featured a six-busbar design. However the Hi-MO 4 offers up to 45 watts of additional power, which appears to come mostly from the module’s slightly larger form factor; the LR4-72HBD’s (Hi-MO 4 series) dimensions are 2131 x 1052 mm, as opposed to 2020 x 996 mm for the LR6-72HBD (Hi-MO 3).

This is inevitably due to larger wafers used for making the half-cut cells. While we were unable to find the exact wafer sizes by press time, it is notable that as the world’s largest monocrystalline ingot and wafer maker, LONGi has been influential in the move to larger diameter wafers. Such larger wafers and cells are showing up in the products of competitors including Jinko Solar and SunPower, with its NGT cells and A-Series.

The LR4-72HBD/Hi-MO 4 still only weighs 28.5 kg, 3 kg more than the LR6, which should not be prohibitive for a two-person carry. LONGi says that this higher power rating allows a 7% reduction in per-watt balance of system costs over the Hi-MO 3.

The launch of the Hi-MO 4 was introduced by pv magazine Managing Director Eckhart Gouras at the Intersolar Europe trade show in Munich. It is only one of several high-powered modules to be introduced at the show, so watch pv-magazine.com and pv-magazine-usa.com for more updates on new products.