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Illustration · 156 half-cut cells
Solar panelTalesun

Talesun TM7G78M 620

156 half-cut cells, bifacial. Power classes 605–640 W in the CEC list.

CEC listed · Jun 21, 2024UL 61730Bifacial
Power class
  • Power (STC)620 WCEC nameplate
  • Efficiency≈22.1%calculated from area
  • %/°C Pmax−0.320CEC listing test
  • PTC / STC94.6%PTC 586 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 8 models
ModelPmaxVoc, VIsc, AVmp, VImp, AEfficiencyPTCCEC listed
TM7G78M-605605 W55.3813.5946.8712.91≈21.6%572 WJun 21, 2024
TM7G78M-610610 W55.5913.6447.0512.97≈21.8%577 WJun 21, 2024
TM7G78M-615615 W55.7913.6947.2413.02≈22.0%582 WJun 21, 2024
TM7G78M-620620 W55.9913.7447.4213.08≈22.1%586 WJun 21, 2024
TM7G78M-625625 W56.1813.7947.6113.13≈22.3%591 WJun 21, 2024
TM7G78M-630630 W56.3713.8447.8013.18≈22.5%596 WJun 21, 2024
TM7G78M-635635 W56.5513.8947.9713.24≈22.7%601 WJun 21, 2024
TM7G78M-640640 W56.7313.9448.1513.30≈22.9%606 WMay 21, 2025
≈ efficiency = Pmax ÷ CEC-listed area 2.8 m².

Heat & cold behaviour

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation
CEC listing test
Pmax coefficient γ−0.320 %/°C
Voc coefficient β−0.238 %/°C
Isc coefficient α+0.046 %/°C
Operating cell temperatureNOCT 43.3 °C
Vmp coefficient ≈ γ − α (CEC); used only for the hot-roof voltage estimate.

Away from lab conditions — CEC listing test points

ClassPmax at NOCTVmp × Imp at NOCTPmax at 200 W/m²Low-light efficiency vs STC
605 W453.9 W43.96 V × 10.33 A118.1 W98%
610 W457.7 W44.13 V × 10.37 A119.1 W98%
615 W461.4 W44.31 V × 10.41 A120 W98%
620 W465.3 W44.47 V × 10.46 A121.1 W98%
625 W468.9 W44.65 V × 10.5 A122 W98%
630 W472.6 W44.83 V × 10.54 A123 W98%
635 W476.4 W44.99 V × 10.59 A124 W98%
640 W480.4 W45.16 V × 10.64 A125 W98%
Pmax = Vmp × Imp from the CEC listing; low-light efficiency = Pmax at 200 W/m² ÷ (20% of STC Pmax).

Certifications

CEC PV Module List (Oct 7, 2026) · Clean Energy Council (Australia)
UL 61730IEC 61215:2021 / IEC 61730:2023

Independent reliability testing

Kiwa PVEL Scorecard · RETC PV Module Index
2025
PVEL Top Performer
closely related product name
2
Tests passed as Top Performer
DH, PID
5
PVEL Scorecards
Talesun named Top Performer, 2017–2025
1
RETC PV Module Index
Talesun, 2024

PVEL Top Performer tests

YearProductTests
2025TM7G78M/xxxM (closely related product name)DHPID

Tested bill of materials

Details describe the tested sample, not every module of the series.

RETC PV Module Index — Talesun

YearRecognition
2024Test Category High Achiever

Inverter compatibility & string sizing

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · NLR PVWatts v8 · inverter datasheets · NLR SAM inverter library · CEC Grid Support Inverter List (Oct 7, 2026)
59.1 V
Voc when cold
per panel
38.9 V
Vmp when hot
per panel
10
Max panels / string
max DC 600 V
2
Min panels / string
MPPT from 60 V
Defaults come from NLR TMY weather (coldest hour, hottest modeled cell). Code calculations (NEC 690.7) use the ASHRAE extreme annual minimum, which is usually colder — enter it above. β is the CEC-measured coefficient; NEC 690.7 calculations use the datasheet value.

String inverters most named in SoCal permits

InverterMax DC inputMPPTWindow sourcePanels per string
Tesla 1538000-xx-y600 V60–480 Vdatasheet2–10
Solis (Ginlong) S6-EH1P10K-H-US600 V80–520 Vdatasheet3–10
Solis (Ginlong) Solis-1P7.6K-4G-US600 V100–500 Vdatasheet3–10
Qcells Q.VOLT H7.6SX498 V234–498 VCEC test window7–8

Microinverters (one per panel)

No microinverter in the reference set lists this power class in its recommended module power range.
Voltage check against the microinverter datasheets — confirm the pairing on the manufacturer’s module compatibility list. Rows appear only when the panel’s power is inside the microinverter’s recommended module power range.
SolarEdge and other optimizer-based systems size strings by the optimizer rules — use the manufacturer’s designer. Reference inverters: most named in SoCal permits since Oct 2024.

Expected production in Southern California

NLR PVWatts v8 · Cali-Graf calculation
CitykWh / kW / yrkWh / panel / yrkWh / system / yrSun, kWh/m²/day
Los Angeles1,6761,03911,4306.08
Palmdale1,8351,13812,5156.69
Chula Vista1,6961,05211,5676.11
Huntington Beach1,6431,01911,2055.89
Riverside1,6961,05211,5676.21
Santa Clarita1,7241,06911,7586.28
746Jan747Feb958Mar1,058Apr1,046May1,111Jun1,170Jul1,184Aug1,035Sep913Oct785Nov679DeckWh per month · Los Angeles
Estimate for comparison, not a quote: shading, roof orientation and local losses change real output. Roof mount, 20° tilt, south, 14% system losses.

Compare with similar 620 W panels

CEC PV Module List (Oct 7, 2026) · Kiwa PVEL Scorecard · datasheets
PanelPmaxEfficiencyγ Pmax (CEC)Voc, VIsc, APVEL (product / brand)
Talesun TM7G78M 620620 W≈22.1%−0.32055.9913.74brand 5×
ZNShine Solar ZXM7-UHLDD144-615/N615 W≈24%−0.28152.914.72product 2024, 2025, 2026
JinkoSolar JKM620N-66HL4M-BDV620 W≈23%−0.29949.0816.08product 2025
Waaree BiN-21-620620 W≥22.9%−0.28849.116.02product 2026
Same fields from the same sources for every row; ≈ efficiency is calculated from the listed area. Comparable series: other brands, same product group, power range covering this class.

About Talesun

CEC PV Module List (Oct 7, 2026) · Kiwa PVEL Scorecard · RETC PV Module Index · building permits

Other series by SoCal permits

TM7G54M · 1TM3F48MTM3F66MTM3G48MTM3G66MTM7F54M

Questions & answers

How efficient is the Talesun TM7G78M 620?

Calculated from the panel area (2.8 m²): about 22.1% for the 620 W class. 620 W over 2.8 m² equals about 221 W per square meter.

How much energy does one panel produce in Los Angeles or Palmdale?

PVWatts v8 with typical-year weather gives about 1,039 kWh per year per 620 W panel in Los Angeles and about 1,138 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.320 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 16.6% below the STC rating.

How many panels fit on one string?

With the Tesla 1538000-xx-y (max DC 600 V, MPPT from 60 V, datasheet) in Los Angeles the calculator gives 2–10 panels per string (Voc at 2 °C = 59.1 V, Vmp at 74 °C cell = 38.9 V). Final design must follow the inverter manual and NEC 690.7.

Is it bifacial?

Yes. Rear gain depends on mounting height and ground reflectance.

Has this panel been reliability-tested?

TM7G78M/xxxM was a PVEL Top Performer in 2025 (DH, PID) — a closely related product name.

Sources

  1. California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
  2. JinkoSolar — datasheet THE MOST DEPENDABLE SOLAR PRODUCT.
  3. Waaree — datasheet ELITE-R-SERIES-BiN-21-600-635-WEL-EPD-600-635-132-BiN-HC.
  4. Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists 2017–2025.
  5. RETC — PV Module Index report.
  6. NLR (formerly NREL) — System Advisor Model CEC module and inverter libraries (version 2026.7.3).
  7. Clean Energy Council (Australia) — Approved PV modules list (as of Oct 8, 2026).
  8. NLR (formerly NREL) — PVWatts v8, NSRDB PSM v3 typical-year weather for Los Angeles, Palmdale, Chula Vista, Huntington Beach, Riverside, Santa Clarita.
  9. Inverter datasheets — Solis (Ginlong), Tesla (manufacturer documents).
  10. Building permits — Southern California permit portals. Equipment matched from permit descriptions.
  11. Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).