What makes the LONGi Hi-MO 9 HydroClear stand out?
- HydroClear anti-dust: a design that reduces dust build-up — on average ≥2% more energy per month and over 30% fewer cleaning and maintenance visits
- High output: 635-670W per panel, up to 24.8% module efficiency with BC cells + TaiRay wafer
- Slow degradation: <1% in year one, then 0.35%/year through year 30 — still producing ≥88.85% at year 30
- Long warranty: 12-year product / 30-year linear power warranty; dual-glass construction rated 5400/2400Pa
If you're comparing top-tier solar panels, the LONGi Hi-MO 9 (model code LR8-66HYD 635~670M) is LONGi's flagship module, and its signature feature is HydroClear anti-dust technology — built to solve the classic solar problem: dirty panels produce less power. This page summarises the key specs from the manufacturer's datasheet so you can compare it against other panels with ease (see our panel-brand overview in Thai, or browse all the equipment we install).
What Kind of Panel Is the Hi-MO 9?
The Hi-MO 9 is a large-format 132-cell panel (arranged 6×22) with a dual-glass construction (2.0+2.0 mm) and an anodised aluminium frame. Output per panel ranges from 635-670W (with a 0~+3% power tolerance — you never get less than the rated figure). At its heart are BC (Back Contact) cells paired with TaiRay wafers, which the manufacturer credits with higher efficiency and reliability plus lower cell operating temperatures, pushing module efficiency as high as 24.8% (670W version). The panel is also bifacial, generating from rear-side light with a bifaciality of 75±5%.
The HydroClear Advantage: An Anti-Dust Panel That Needs Less Cleaning
Dust on the panel face is the silent enemy of any solar system — the dirtier the panel, the more power you lose. HydroClear is LONGi's anti-dust design that helps rainwater rinse the panel face more effectively, reducing dirt build-up. The manufacturer's figures state:
- At least 2% more energy per month on average, compared with a panel left to soil naturally
- Maintenance and panel-cleaning frequency cut by more than 30% — meaning lower upkeep costs over the long run
- High-blocking encapsulation with mechanical load ratings of 5400Pa front and 2400Pa rear
What also makes this model attractive as a long-term investment is its very low degradation rate: no more than 1% in the first year, then just 0.35% per year through years 2-30, backed by a 30-year linear power warranty — at year 30 the panel is still guaranteed to produce at least 88.85% of its day-one output.
Key Specs (From the Manufacturer's Datasheet)
| Item | LONGi Hi-MO 9 (LR8-66HYD) spec |
|---|---|
| Rated power (Pmax) | 635-670W (0~+3% tolerance) |
| Max module efficiency | 24.8% (the 645W version is 23.9%) |
| Cell type | BC (Back Contact) + TaiRay wafer, 132 cells (6×22), bifacial 75±5% |
| Power degradation | Year one <1% · years 2-30 at 0.35%/year |
| Warranty | Product/workmanship 12 years · 30-year linear power (≥88.85% at year 30) |
| Construction | Dual glass, 2.0+2.0 mm heat-strengthened glass, anodised aluminium frame |
| Mechanical load | Front 5400Pa · rear 2400Pa · hail tested with 25 mm hail at 23 m/s |
| Dimensions / weight | 2382 × 1134 × 30 mm / 32.6 kg |
| Junction box | IP68 with 3 diodes, 4 mm² cable |
| Operating temperature range | -40°C to +85°C · Pmax temp. coefficient -0.260%/°C |
| Max system voltage | DC 1500V (IEC/UL) · Protection Class II |
| Certifications | IEC 61215, IEC 61730, UL 61730 · ISO 9001/14001/45001 |
Need the full spec sheet for every power grade (635-670W)? Download the original manufacturer document here:
Who Is It For?
The Hi-MO 9 suits homes, villas and businesses that want high output per panel and minimal cleaning — especially in Phuket, where the dry season brings dust and seaside locations coat panels quickly with salt spray. A panel that limits dirt build-up on its own means less production lost between cleaning rounds and fewer maintenance bills (read more on how coastal conditions affect equipment in Thai).
With its large format (2382×1134 mm) and high output per panel, this model pays off most where roof space is limited but you want maximum installed capacity — villas with large systems, or hotels and businesses with heavy daytime loads. To match the right panel to your roof structure and budget, our team assesses everything on a real site survey. Ask for pricing — it costs nothing.