The Renogy 640W (2 x 320W) N-Type 18BB Rigid Solar Panel 2-Pack and the SUNGOLDPOWER 1800W (4 x 450W) Monocrystalline PERC Rigid Solar Panel 4-Pack (SG450WM, UL 61730) are evenly matched, rated 4.0 and 4.0. The Renogy 640W (2 x 320W) N-Type 18BB Rigid Solar Panel 2-Pack leads on efficiency. The SUNGOLDPOWER 1800W (4 x 450W) Monocrystalline PERC Rigid Solar Panel 4-Pack (SG450WM, UL 61730) wins on value. The Renogy 640W (2 x 320W) N-Type 18BB Rigid Solar Panel 2-Pack costs $650.01 less ($599.99 vs $1,250).
A large-panel pair for a cabin, shed or ground-mount array with a high-voltage MPPT controller. Too big and too high-voltage for most van and small RV setups.
Amazon $599.99 Renogy $599.99A budget 4-pack of large 450 W panels for a home roof, shed or ground-mount array on a 24 V or 48 V MPPT system. Too big for RVs and vans.
Amazon $1,250 SUNGOLDPOWER $1,250Prices were last checked October 21, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Each factor is scored 0-100 against the same fixed reference points for every 150 w and up rigid solar panel; a clear win is highlighted. How we rank explains each one.
| Factor weight | Renogy 640W (2 x 320W) N-Type 18BB Rigid Solar Panel 2-Pack | SUNGOLDPOWER 1800W (4 x 450W) Monocrystalline PERC Rigid Solar Panel 4-Pack (SG450WM, UL 61730) |
|---|---|---|
| Overall rating | 4.0/5 | 4.0/5 |
| Value 45% | 54 $0.94 per rated watt | 77 $0.69 per rated watt |
| Tested output 15% | 50 not yet independently tested (neutral score used) | 50 not yet independently tested (neutral score used) |
| Durability 25% | 100 IP68, 10-year warranty | 100 IP68, 12-year warranty |
| Efficiency 15% | 100 25% claimed efficiency | 30 20.8% claimed efficiency |
| Renogy 640W (2 x 320W) N-Type 18BB Rigid Solar Panel 2-Pack | SUNGOLDPOWER 1800W (4 x 450W) Monocrystalline PERC Rigid Solar Panel 4-Pack (SG450WM, UL 61730) | |
|---|---|---|
| Output | ||
| Rated power | 640 W | 1,800 W |
| Efficiency | 25% (cell efficiency, "up to"; datasheet module efficiency 22.2%) | 20.8% (module efficiency) |
| Cells | Monocrystalline (N-type, 18BB (per Renogy's product page and Amazon; the datasheet says only monocrystalline, 60 cells)) | Monocrystalline (PERC, 120 half-cut 182 mm cells) |
| Bifacial | No | No |
| Electrical | ||
| Open-circuit voltage (Voc) | 43.8 V | 41.7 V |
| Voltage at max power (Vmp) | 37.9 V | 34.2 V |
| Short-circuit current (Isc) | 8.9 A | 13.8 A |
| Current at max power (Imp) | 8.5 A | 13.2 A |
| Voc temperature coefficient | -0.3%/°C | -0.3%/°C |
| Series / parallel | - | Yes |
| Connections | ||
| Output connector | Solar connectors (IP68) | - |
| Build | ||
| Weight | - | 54 lb (24.5 kg) |
| Dimensions | 64.6 x 34.7 x 1.4 in (each panel) | 75.16 x 44.65 x 1.38 in (each panel) |
| Frame | anodized aluminum alloy | anodized aluminum alloy |
| Glass | 3.2 mm tempered | 3.2 mm tempered |
| Junction box rating | IP68 | IP68 |
| Warranty | 10 years | 12 years |
| Output warranty | 95% output for 5 years, 90% for 10 years, 80% for 25 years | 95% output at 5 years, 90% at 10 years, 80% at 25 years |
