425 W TOPCon solar panel with 108 cells. Voc 38.11 V · Isc 14.03 A · TcVoc -0.26%/°C.
Select the panel you want to replace
Panel not in the catalogue?
148 of the 4,444 panels in the catalogue can replace TommaTech TT425-108TNFB10 Dark Series. Before you buy, check your pick in the string calculator with your inverter.
CloseNoticeableLarge differenceTap or click a difference to see what it means for your string.
Near-identical electrics — a drop-in swap for the same string.
Match 96 % · 3 models
Small differences within tolerance — safe once verified in the calculator with your inverter.
Match 80–94 % · 17 models
Noticeable differences — the string voltage and current need a careful check.
Match 61–79 % · 41 models
Large differences — a real risk of a mismatched string; prefer a closer panel.
Match 29–59 % · 87 models
String Compatibility Calculator
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Panel Matcher
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How the Algorithm Works
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Voc
38.11 V
Vmpp
32.14 V
Isc
14.03 A
Impp
13.23 A
TcVoc
-0.26 %/°C
TcPmax
-0.3 %/°C
Pmax
425 W
Cells
108
Length
1722 mm
Width
1134 mm
Thickness
30 mm
Weight
21.45 kg
The TommaTech TT425-108TNFB10 Dark Series is a 425 W solar panel. Finding a compatible replacement requires matching the original electrical characteristics — particularly Voc, Vmpp, Isc, and temperature coefficients — to ensure safe operation within the same string.
Use the form above to find panels that match these specifications. Then verify the replacement in the String Compatibility Calculator with your inverter.
| Model | Power | Voc | Isc |
|---|---|---|---|
| TT415-108TNFB10 Dark Series | 415 W | 37.71 V | 13.88 A |
| TT420-108TNFB10 Dark Series | 420 W | 37.91 V | 13.95 A |
| TT430-108TNFB10 Dark Series | 430 W | 38.31 V | 14.1 A |
| TT435-108TNFB10 Dark Series | 435 W | 38.51 V | 14.17 A |
| TT440-108TNFB10 Dark Series | 440 W | 38.71 V | 14.24 A |
| TT445-108TNFB10 Dark Series | 445 W | 38.91 V | 14.31 A |
| TT450-108TNFB10 Dark Series | 450 W | 39.11 V | 14.38 A |
The most critical specs to match are: cell count (must be exactly 108), Voc close to 38.11 V (within ±5%), and temperature coefficient TcVoc close to -0.26%/°C. If Voc differs significantly, the string voltage at extreme temperatures may shift outside the inverter's MPPT range. The replacement finder above pre-screens all candidates by these criteria.
A higher wattage panel usually has a higher Vmpp or Isc, which can affect string voltage and current. Small increases (up to 10–15%) are typically safe if the other electrical specs align. The replacement finder shows a compatibility score — 'Exact match' means the specs align closely. Always verify the replacement in the String Compatibility Calculator with your inverter before installation.
If the replacement has a significantly different Voc or Vmpp, the string voltage may shift outside the inverter's MPPT range, reducing energy production or causing faults. This effect is amplified at temperature extremes: at low temperatures, voltage rises by the TcVoc coefficient. The replacement finder automatically accounts for this — it scores candidates by how closely the electrical specs match the original TommaTech TT425-108TNFB10 Dark Series.