Longi Solar panel review




LonGi are a very Chinese large panel manufacturer making hundreds of millions of panels a year.
Solar4Ever were one of the first installers in Perth to try out LonGi, many years ago, and our client feedback has been excellent. The panels are consistently well-made, although the same can be said for all of the Tier 1 brands. There really is so little difference between any of them, and with no moving parts apart from electrons whizzing around producing electrical current, there's little to go wrong with a robot-made panel.

The particular small advantage I like about the LonGi 370W is the lower than normal open circuit voltage. It's about 4V lower than other 370W panels and allows us to install an extra panel (13) per string.

The best selling LonGi panels is the 370W, because as with all other 370W panels, if you connect 18 of them you get a 6.66kW system, which is the maximum allowed in WA for single phase installs until you connect a battery (9.62kW of panel power allowed with the Huawei 5kW inverters and 8.88kW with the Fronius GEN24Plus when you plug in their batteries). There is also a LonGi 450W model. Physically larger and the same efficiency as the 370W, but not sure why people install this panel, intended for commercial installs on their homes, because you end up with a 6.3kW system as 14 panels is 6.3kW but add a 14th and you are 6.75kW and over the 6.66kW limit.

The efficiency of the 370W LonGi HiMo4m panel is 20% which is the same as with any other 370W panel from JinKo, Leapton, Trina, Canadian etc.

12 year defect warranty. A bit low when most others are 15 years and Leapton now 25 years.

The 370W HiMo 4m panel dimensions are 1755mm x 1038mm and they have a black frame.

It is a 120 half-cell 'P' type monocrystalline design. Normal.

Salt mist/ammonia severity resistance rating is 5. The highest level possible is 6.

The temperature power loss factor is -0.27% per °C . It means that for every °C the temperature rises, the output reduces by 0.27%. That's fractionally (0.01%) better than the usual 0.28%, but we are talking a cup of coffee a year in value.

Price is normal at approx $185 per panel, less STC subsidy of $185 = Free.

LonGi have an office in Sydney. Call 02 8484 5806


Would I put LonGi panels on my own roof?
Actually I did put one on my roof, years ago when they first came out, with an optimiser fitted, to check on how it performed before we sold any, and it did exactly what it claimed to do, as have all the others we have installed on customer rooftop's around Perth since. There is an all-black version, pictured above, achieved in the same way as LG make an all-black, by overlapping the cells so the white backsheet is hidden. It's in and out of stock, unreliable supply, and as with all other 'all-blacks' slightly less efficient at 350W but if we can get hold of them, its a nice aesthetically pleasing choice especially if visible from the road.
We have installed LonGis for a couple of years with no issues at all.
If you want a quote for solar with LonGi panels then call us on...

(08) 6102 2527


or email

LonGi 370W brochure



This review was written by Andrew MacKeith, Solar4Ever service manager since 2011.
Most recent update April 2021