Illustration · 156 half-cut cells

Solar panelTalesun

Talesun TD7G78M 580

Name: Talesun TD7G78M 580
Brand: Talesun

156 half-cut cells, bifacial, transparent backsheet. Power classes 570–590 W in the CEC list.

CEC listed · Sep 1, 2023UL 61730BifacialPVEL Top Performer 2022

Power class

Power (STC)580 WCEC nameplate
Efficiency≈20.8%calculated from area
%/°C Pmax−0.335CEC listing test
PTC / STC94.2%PTC 546 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 5 models

Model	Pmax	Voc, V	Isc, A	Vmp, V	Imp, A	Efficiency	PTC	CEC listed
TD7G78M-570	570 W	53.30	13.65	44.68	12.76	≈20.4%	536 W	Sep 1, 2023
TD7G78M-575	575 W	53.44	13.72	44.82	12.83	≈20.6%	541 W	Sep 1, 2023
TD7G78M-580	580 W	53.59	13.79	44.97	12.90	≈20.8%	546 W	Sep 1, 2023
TD7G78M-585	585 W	53.73	13.86	45.11	12.97	≈20.9%	551 W	Sep 1, 2023
TD7G78M-590	590 W	53.87	13.93	45.25	13.04	≈21.1%	556 W	Sep 1, 2023

≈ efficiency = Pmax ÷ CEC-listed area 2.79 m².

Build & dimensions

CEC PV Module List (Oct 7, 2026)

Module area2.79 m² (30.1 ft²)CEC-listed area
Cells156 half-cut cells
Back coverTransparent backsheet

Heat & cold behaviour

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation

	CEC listing test
Pmax coefficient γ	−0.335 %/°C
Voc coefficient β	−0.255 %/°C
Isc coefficient α	+0.044 %/°C
Operating cell temperature	NOCT 43.3 °C

Vmp coefficient ≈ γ − α (CEC); used only for the hot-roof voltage estimate.

Away from lab conditions — CEC listing test points

Class	Pmax at NOCT	Vmp × Imp at NOCT	Pmax at 200 W/m²	Low-light efficiency vs STC
570 W	397 W	38.17 V × 10.4 A	104 W	91%
575 W	400.7 W	38.32 V × 10.46 A	105 W	91%
580 W	404.4 W	38.46 V × 10.51 A	105.9 W	91%
585 W	408.1 W	38.61 V × 10.57 A	106.9 W	91%
590 W	411.8 W	38.76 V × 10.63 A	107.9 W	91%

Pmax = Vmp × Imp from the CEC listing; low-light efficiency = Pmax at 200 W/m² ÷ (20% of STC Pmax).

Independent reliability testing

Kiwa PVEL Scorecard · RETC PV Module Index

2022

PVEL Top Performer

this series

Tests passed as Top Performer

DH, LID+LETID, PID

PVEL Scorecards

Talesun named Top Performer, 2017–2025

RETC PV Module Index

Talesun, 2024

PVEL Top Performer tests

Year	Product	Tests
2022	TD7G78M-xxx	DHLID+LETIDPID

Tested bill of materials

Cell technology (tested BOM)p-type PERC
Module design (tested BOM)Bifacial - glass//glass
Power class range tested555-600W

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

RETC PV Module Index — Talesun

Year	Recognition
2024	Test 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)

CityColdest air, °CHottest cell, °CString inverter

56.7 V

Voc when cold

per panel

36.6 V

Vmp when hot

per panel

Max panels / string

max DC 600 V

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

Inverter	Max DC input	MPPT	Window source	Panels per string
Tesla 1538000-xx-y	600 V	60–480 V	datasheet	2–10
Solis (Ginlong) S6-EH1P10K-H-US	600 V	80–520 V	datasheet	3–10
Solis (Ginlong) Solis-1P7.6K-4G-US	600 V	100–500 V	datasheet	3–10
Qcells Q.VOLT H7.6SX	498 V	234–498 V	CEC test window	7–8

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

PanelsCity for chartSystem size

City	kWh / kW / yr	kWh / panel / yr	kWh / system / yr	Sun, kWh/m²/day
Los Angeles	1,676	972	11,665	6.08
Palmdale	1,835	1,064	12,772	6.69
Chula Vista	1,696	984	11,804	6.11
Huntington Beach	1,643	953	11,435	5.89
Riverside	1,696	984	11,804	6.21
Santa Clarita	1,724	1,000	11,999	6.28

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 580 W panels

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

Panel	Pmax	Efficiency	γ Pmax (CEC)	Voc, V	Isc, A	PVEL (product / brand)	SoCal permits (series)
Talesun TD7G78M 580	580 W	≈20.8%	−0.335	53.59	13.79	product 2022	—
ZNShine Solar ZXM7-UHLDD144-580/N	580 W	≈22.7%	−0.281	51.5	14.35	product 2024, 2025, 2026	1
VSUN (Vietnam Sunergy) VSUN580N-144MH	580 W	≈22.5%	−0.309	52.02	13.83	brand 6× (2021–2026)	1
Phono Solar PS580M8GFH-24/TNH	580 W	≈22.7%	−0.293	52.7	13.66	product 2024, 2025	1

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

ManufacturerTalesun
Listed in CEC asSuzhou Talesun Solar Technologies Co., Ltd.
PVEL Top Performer (manufacturer)5 Scorecards (2017–2025)
RETC PV Module Index2024
Current panel series in CEC list34

Other series by SoCal permits

TM7G54M · 1TM3F48MTM3F66MTM3G48MTM3G66MTM7F54M

Questions & answers

How efficient is the Talesun TD7G78M 580?

Calculated from the panel area (2.79 m²): about 20.8% for the 580 W class. 580 W over 2.79 m² equals about 208 W per square meter.

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

PVWatts v8 with typical-year weather gives about 972 kWh per year per 580 W panel in Los Angeles and about 1,064 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.335 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 17.4% 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 = 56.7 V, Vmp at 74 °C cell = 36.6 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?

TD7G78M-xxx was a PVEL Top Performer in 2022 (DH, LID+LETID, PID).

Sources

California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists 2017–2025.
RETC — PV Module Index report.
NLR (formerly NREL) — System Advisor Model CEC module and inverter libraries (version 2026.7.3).
NLR (formerly NREL) — PVWatts v8, NSRDB PSM v3 typical-year weather for Los Angeles, Palmdale, Chula Vista, Huntington Beach, Riverside, Santa Clarita.
Inverter datasheets — Solis (Ginlong), Tesla (manufacturer documents).
Building permits — Southern California permit portals. Equipment matched from permit descriptions.
Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).