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Trina Solar TSM-DEG21C.20-660
Trina Solar Brand review

TSM-DEG21C.20-660

660 Wp PERC Bifacial 70%
ComparePV verdict

Middle of its segment, heavy for its output

Rank 3,228 of 14,005
Compare panels Datasheet PDF
Power (Wp)
660
Typical for its class
Efficiency (%)
21.20
Typical · median 21.25%
Density (Wp/m²)
212.5
Typical · median 212.5
Temp (%/°C)
-0.340
Typical · median -0.340
Weight (kg)
38.3
Weak · 3.8 kg above median
Warranty (yrs)
30
Typical · median 30 yrs

Trina Solar's Vertex TSM-DEG21C.20 645-665W series is designed specifically for maximizing energy yield in large-scale installations, where every square meter and every hour of the installation team's work matters. The modules utilize monocrystalline wafers in a large-format architecture and high-density interconnection technology, which translates to better light utilization even under low irradiance and on cloudy days.

The key advantage of this series is the low-voltage, high-power string concept - it simplifies string configuration design, making equipment selection easier and reducing the cost of Balance of System (BOS) components. In practice, this means simpler PV farm design and greater system performance predictability.

Vertex DEG21C.20 also boasts enhanced resistance to microcracks thanks to precise cutting methods and increased reliability in challenging conditions (e.g., high humidity, salinity, dust). This makes it an excellent choice for utility-scale solar farms, commercial and industrial installations, and tracker projects where stable performance and longevity are essential.

Ranking

320 panels in the segment PERC 650-700 W
Metric This panel Median Position in segment Overall rank
Module efficiency 21.20% 21.25% Typical 9,076
Power density 212.5 212.5 Typical 8,959
Temperature coefficient -0.340 -0.340 Typical 8,778
Weight per kWp 58.0 52.3 Weak · bottom 22% 11,529
Performance warranty 30 yrs 30 yrs Typical 21
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Signals from the data

0 positive · 1 caution
Best for

Utility-scale and commercial.

Not ideal for

Weight-limited structures.

Watch-outs
58.0 kg per kWp

Bottom 22% of the PERC 650-700 W segment, against a median of 52.3.

Notes from the database
  • At 21.2% efficiency, this panel is on par with typical PERC 650-700W modules
  • Power density of 212.5 W/m² matches the PERC 650-700W median
  • At -0.34%/°C, hot weather performance is typical for PERC 650-700W panels
  • Weight of 38.3 kg is 3.8 kg above PERC 650-700W median (34.5 kg) - verify structural support
  • Bifacial design (70% factor) captures reflected light - adds 4-10% yield on ground-mount or white roof

Specifications

Open datasheet PDF
Nominal power (Pmax) 660 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 21.20 % Typical Segment median 21.25%
Vmpp · Impp 38.10 V · 17.35 A Operating point at max power
Voc · Isc 45.90 V · 18.45 A Sizes the string length
Max system voltage 1500 V Longer strings than 1000 V modules
Dimensions 2384×1303×33 mm · 3.11 m² of roof
Weight 38.3 kg Weak Weak · 3.8 kg above median
Cells 132 · PERC Monocrystalline
Bifaciality 70 % Rear output as a share of front
Coefficient Pmax -0.340 %/°C Typical median -0.340 of its segment
Coefficient Voc · Isc -0.250 · 0.040 %/°C
NOCT 43 °C At 800 W/m², 20 °C ambient
Product warranty 12 years Hardware defects only
Performance warranty 30 years Typical median 30 yrs · median 30 yrs
End-of-warranty output 85.0 % Equals 561 W guaranteed
Degradation 2.00 → 0.45 % First year, then annual

Simulations

Live - change any input
Lifetime output & value
30 years at 1200 kWh/kWp/year and €0.50 per kWh
Power in year 30
-
Lifetime energy
-
Energy value
-
With bifacial gain
-

Degradation from this panel's own datasheet figures. No inverter, soiling or shading losses.

Heat losses
-0.340 %/°C against a segment median of -0.340
-
Bifacial gain
Rear gain over light concrete: -
-

Model: bifaciality × albedo × 0.6 view factor. A first-order estimate, not a yield simulation.

Filter these
Size
Panel Power Eff. Temp. Weight Difference
Trina Solar TSM-DEG21C.20-660 660 W 21.20% -0.340 38.3 kg You are here
AIKO-A650-MAE72Mw 650 W 25.20% -0.260 27.0 kg Cooler, lighter, +4.0 pp
AIKO-A680-MDE72Mw 680 W 25.20% -0.260 29.0 kg Cooler, lighter, +4.0 pp
AIKO-A675-MDE72Mw 675 W 25.00% -0.260 29.0 kg Cooler, lighter, +3.8 pp
AIKO-A645-MAE72Mw 645 W 25.00% -0.260 27.0 kg Cooler, lighter, +3.8 pp
AIKO-A700-MAE78Dw 700 W 25.00% -0.260 34.5 kg +40 W, cooler, +3.8 pp
AIKO-A695-MAE78Dw 695 W 24.90% -0.260 34.5 kg Cooler, lighter, +3.7 pp
AIKO-G670-MCH72Mw 670 W 24.80% -0.260 28.2 kg Cooler, lighter, +3.6 pp
TSM-DEG21C.20-645 645 W 20.80% -0.340 38.3 kg -15 W, -0.4 pp
TSM-DEG21C.20-650 650 W 20.90% -0.340 38.3 kg -10 W, -0.3 pp
TSM-DE21-655W 655 W 21.10% -0.340 32.3 kg Lighter, -5 yr warranty
TSM-DE21-665W 665 W 21.40% -0.340 32.3 kg Lighter, -5 yr warranty
TSM-DE21-670W 670 W 21.50% -0.340 32.3 kg Lighter, +0.3 pp, -5 yr warranty
TSM-DE21-675W 675 W 21.70% -0.340 32.3 kg Lighter, +0.5 pp, -5 yr warranty
AIKO-A805-GRH78Dw 805 W 25.10% -0.260 39.8 kg +145 W, cooler, +3.9 pp
AIKO-A800-GRH78Dw 800 W 24.90% -0.260 39.8 kg +140 W, cooler, +3.7 pp
AIKO-A795-GRH78Dw 795 W 24.80% -0.260 39.8 kg +135 W, cooler, +3.6 pp

Found 1390 panels of the same or similar size to this one, within ±10 mm. See them here Found 1400 panels of the same or similar size to this one, within ±25 mm. See them here Found 1400 panels of the same or similar size to this one, within ±50 mm. See them here Found 1432 panels of the same or similar size to this one, within ±100 mm. See them here

Common questions

6 answered
What warranty comes with the Trina Solar Vertex TSM-DEG21C.20 645-665W series?
The series carries a 12-year product warranty and a 30-year power output warranty. This means Trina Solar commits to repairing or replacing modules with manufacturing defects for 12 years, while guaranteeing a defined performance level for 30 years. This is one of the longer warranty periods on the market, reducing investment risk for large-scale installations.
Do the bifacial DEG21C.20 modules require special mounting structures?
Bifacial modules in this series perform best on structures that allow light reflection onto the rear side, such as trackers, ground-mount systems raised above the surface, or light-colored ground (gravel, white roofing). No dedicated clamps are required, but leaving minimum clearance under the panel and avoiding dark, absorptive surfaces helps maximize the extra rear-side energy gain.
What is the low-voltage, higher-power-string concept behind Vertex DEG21C.20?
Thanks to higher per-module power (up to 665 Wp), a string of the same total capacity can be built from fewer panels while keeping voltage within a safe range for typical inverters. This means fewer connectors, shorter DC cabling, and simpler PV plant design, lowering balance-of-system (BoS) costs and reducing installation time on large projects.
Is PERC cell technology in the Vertex DEG21C.20 outdated compared to TOPCon?
PERC remains a proven, mature technology with a strong price-to-performance ratio, though newer TOPCon cells offer slightly higher efficiency and slower annual degradation. For large commercial installations, PV farms, and tracker-based projects where predictable cost and stable supply matter most, the PERC-based Vertex DEG21C.20 series remains a solid, competitive choice, especially at high purchase volumes.
What types of installations is the Trina Vertex TSM-DEG21C.20 645-665W series best suited for?
This series is designed for large-scale projects: solar farms, commercial and industrial rooftops, and single-axis tracker installations. The large module format and high unit power up to 665 Wp reduce the number of panels needed per megawatt, shortening installation crew time and lowering mounting structure costs compared to smaller residential modules.
Does Trina Solar's Tier 1 status add extra security for investors?
Yes, Trina Solar is a China-based manufacturer classified as Tier 1, reflecting long-term financial stability, large-scale production capacity, and a track record of honoring warranties. For investors in commercial installations and PV farms, this lowers the risk of the manufacturer exiting the market before the 30-year power warranty expires and ensures easier access to service and replacement parts.
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