LONGi 550W vs 650W Solar Panel: Hi-MO 5 LR5-72HBD or Hi-MO 9 LR8-66HYD
A LONGi 550 W panel and a LONGi 650 W panel are the two ratings buyers most often type as a number, and in this catalogue they are two different generations: the Hi-MO 5 LR5-72HBD 550W and the Hi-MO 9 LR8-66HYD 650W. This page reads both product records side by side. The headline is not only the extra rated power. The Hi-MO 9 record states 24.1% module efficiency against 21.3% on the Hi-MO 5, in a frame 2382 mm long instead of 2278 mm at the same 1134 mm width. And the two behave differently at the inverter: their open-circuit voltages are almost equal, while the Hi-MO 9 delivers a markedly higher current. That last point, more than the wattage, is what decides whether a panel suits the inverter already on the wall.
Specifications side by side
Every figure in this table is read from the product’s own record — the same rows each product page shows.
| Specification | LONGi Hi-MO 5 LR5-72HBD 550W | LONGi Hi-MO 9 LR8-66HYD 650W |
|---|---|---|
| Maximum Power (Pmax) | 550 W | 650 W |
| Open Circuit Voltage (Voc) | 49.8 V | 49.42 V |
| Module Efficiency | 21.3 % | 24.1 % |
| Temperature Coefficient of Pmax | -0.34 % | -0.26 % |
| Short Circuit Current (Isc) | 13.99 A | 16.3 A |
| Voltage at Maximum Power (Vmpp) | 41.25 V | 40.58 V |
| Current at Maximum Power (Impp) | 13.21 A | 15.61 A |
| Temperature Coefficient of Voc | -0.26 % | -0.2 % |
| Temperature Coefficient of Isc | 0.05 % | 0.05 % |
| Maximum System Voltage | 1500 V | 1500 V |
| Maximum Series Fuse Rating | 30 A | 35 A |
| Dimensions (W×H×D) | 2278×1134×30 mm | 2382×1134×30 mm |
| Weight | 31.8 kg | 33.5 kg |
| Frame Material | Anodized aluminum alloy frame | Weather-resistant anodized aluminum frame |
| Glass | Dual glass, 2.0+2.0mm heat strengthened glass | Dual glass, weather-resistant semi-tempered glass |
| Front Side Maximum Static Loading | 5400 Pa | 5400 Pa |
| Rear Side Maximum Static Loading | 2400 Pa | 2400 Pa |
| Operating Temperature | -40 ~ 85 °C | -40 ~ 85 °C |
| Warranty | 12 Years Product, 30 Years Performance | 12 Years Product, 30 Years Performance |
| Price | AED 341 | AED 403 |
Power, Efficiency and Size
The Hi-MO 5 LR5-72HBD record states a maximum power (Pmax) of 550 W at 21.3% module efficiency, in a 2278×1134×30 mm frame weighing 31.8 kg. The Hi-MO 9 LR8-66HYD record states a maximum power (Pmax) of 650 W at 24.1% module efficiency, in a 2382×1134×30 mm frame weighing 33.5 kg. Both are 1134 mm wide and 30 mm deep, so they sit on the same rail spacing across the short side; the Hi-MO 9 is the longer and the heavier of the two. Where roof area is the limit, the higher efficiency of the Hi-MO 9 is the figure that matters: more rated power from each square metre the array covers.
Voltage and Current: the Inverter Question
Here the two records part ways. Hi-MO 5 LR5-72HBD: a Voc of 49.8 V, a Vmp of 41.25 V, an Isc of 13.99 A and an Imp of 13.21 A. Hi-MO 9 LR8-66HYD: a Voc of 49.42 V, a Vmp of 40.58 V, an Isc of 16.3 A and an Imp of 15.61 A. With nearly the same open-circuit voltage, the number of panels a string can hold is decided the same way for both. The current is not the same: before choosing the Hi-MO 9, check the maximum input current per MPPT of your inverter against its Isc of 16.3 A. The maximum series fuse rating follows the same pattern — 30 A on the Hi-MO 5 record, 35 A on the Hi-MO 9 record. Both are rated for a 1500 V system.
Heat, Glass and What Each Record Describes
The temperature coefficient of Pmax is -0.34%/°C on the Hi-MO 5 record and -0.26%/°C on the Hi-MO 9 record, so the Hi-MO 9 gives up less of its rating as the module heats. Both are dual-glass modules: the Hi-MO 5 record states 2.0+2.0 mm heat strengthened glass and a bifaciality of 70%, and describes an M10 gallium-doped wafer with 9-busbar half-cut cells. The Hi-MO 9 record describes a build for high-corrosion scenarios such as offshore areas — a humidity-resistant junction box and connector, dual-layer coated glass and a special aluminum frame for salt corrosion resistance — with BC-cell technology for a lower operating temperature. Static loads are the same on both: 5400 Pa front, 2400 Pa rear.
Which One for Which Project
Take the Hi-MO 5 LR5-72HBD 550W when the inverter is already chosen and its MPPT input current is sized around 14 A-class modules, or when an existing array of the same format is being extended. Take the Hi-MO 9 LR8-66HYD 650W when roof area is the constraint, when the site is hot, or when it is coastal and humid — the conditions its record is written for — and the inverter accepts the higher current. Both carry the same warranty, 12 years on the product and 30 years on performance, and both are priced on this site by the same rule of USD 0.169 per watt, so neither rating carries a premium per watt.
The models in this comparison
LONGi Hi-MO 5 LR5-72HBD 550W
AED 341
LONGi Hi-MO 9 LR8-66HYD 650W
AED 403
Winner
Hi-MO 9 LR8-66HYD 650W for area-limited, hot or coastal roofs with an inverter that accepts an Isc of 16.3 A; Hi-MO 5 LR5-72HBD 550W for inverters sized around lower-current modules and for extending arrays of its format.
Conclusion
The LONGi 550 W and 650 W panels are separated by more than a rating. The Hi-MO 9 LR8-66HYD reaches 24.1% efficiency against 21.3% on the Hi-MO 5 LR5-72HBD, holds its power better in heat at -0.26%/°C against -0.34%/°C, and is built for corrosive, humid sites. It is also 2382 mm long against 2278 mm, weighs 33.5 kg against 31.8 kg, and pushes an Isc of 16.3 A where the Hi-MO 5 states 13.99 A. Check the inverter's input current first; if it fits, the Hi-MO 9 is the stronger panel for a constrained roof, and the Hi-MO 5 remains the fit for systems designed around its current.