Illustration · 144 half-cut cells

Solar panelQcells

Qcells Q.PEAK DUO L-G6.3/BFG 420

Name: Qcells Q.PEAK DUO L-G6.3/BFG 420
Brand: Qcells

144 half-cut cells, bifacial. Power classes 400–440 W in the CEC list.

CEC listed · Feb 1, 2021UL 61730BifacialPVEL Top Performer 2022

Power class

Power (STC)420 WCEC nameplate
Efficiency≈20.2%calculated from area
%/°C Pmax−0.334CEC listing test
PTC / STC93.4%PTC 392 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 9 models

Model	Pmax	Voc, V	Isc, A	Vmp, V	Imp, A	Efficiency	PTC	CEC listed
Q.PEAK DUO L-G6.3/BFG 400	400 W	47.89	10.60	39.63	10.09	≈19.3%	373 W	Feb 1, 2021
Q.PEAK DUO L-G6.3/BFG 405	405 W	48.14	10.65	39.95	10.14	≈19.5%	378 W	Feb 1, 2021
Q.PEAK DUO L-G6.3/BFG 410	410 W	48.39	10.70	40.27	10.18	≈19.7%	383 W	Feb 1, 2021
Q.PEAK DUO L-G6.3/BFG 415	415 W	48.63	10.74	40.58	10.23	≈20.0%	388 W	Feb 1, 2021
Q.PEAK DUO L-G6.3/BFG 420	420 W	48.88	10.79	40.89	10.27	≈20.2%	392 W	Feb 1, 2021
Q.PEAK DUO L-G6.3/BFG 425	425 W	49.13	10.83	41.20	10.32	≈20.5%	397 W	Feb 1, 2021
Q.PEAK DUO L-G6.3/BFG 430	430 W	49.38	10.88	41.50	10.36	≈20.7%	402 W	Feb 1, 2021
Q.PEAK DUO L-G6.3/BFG 435	435 W	49.63	10.92	41.81	10.41	≈21.0%	407 W	Feb 1, 2021
Q.PEAK DUO L-G6.3/BFG 440	440 W	49.87	10.97	42.11	10.45	≈21.2%	412 W	Feb 1, 2021

≈ efficiency = Pmax ÷ CEC-listed area 2.08 m².

CEC note: Formerly listed under Hanwha Q CELLS

Heat & cold behaviour

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

	CEC listing test
Pmax coefficient γ	−0.334 %/°C
Voc coefficient β	−0.263 %/°C
Isc coefficient α	+0.041 %/°C
Operating cell temperature	NOCT 45.5 °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
400 W	297.4 W	37 V × 8.04 A	76.1 W	95%
405 W	301.3 W	37.3 V × 8.08 A	77.1 W	95%
410 W	304.9 W	37.6 V × 8.11 A	78 W	95%
415 W	308.8 W	37.88 V × 8.15 A	79 W	95%
420 W	312.4 W	38.17 V × 8.18 A	79.9 W	95%
425 W	316.3 W	38.46 V × 8.22 A	80.9 W	95%
430 W	319.8 W	38.74 V × 8.25 A	81.8 W	95%
435 W	323.8 W	39.03 V × 8.29 A	82.9 W	95%
440 W	327.3 W	39.31 V × 8.33 A	83.8 W	95%

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

LID+LETID, PAN, TC

PVEL Scorecards

Qcells named Top Performer, 2016–2026

2023, 2026

RETC Overall Highest Achiever

Qcells, manufacturer level

PVEL Top Performer tests

Year	Product	Tests
2022	Q.PEAK DUO L-G6.3/BFG	LID+LETIDPANTC

Tested bill of materials

Cell technology (tested BOM)p-type PERC
Module design (tested BOM)Bifacial - glass//glass
Power class range tested405-450W

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

RETC PV Module Index — Qcells

Year	Recognition
2023	Overall Highest Achiever; High Achievement in Performance (Module efficiency, Pan file performance); High Achievement in Reliability (Damp heat test, Pid resistance, Thermal cycle test)
2024	High Achievement in Performance
2025	Performance High Achiever
2026	Overall Highest Achiever; High achievement in performance; High achievement in reliability; Performance discipline high achiever (Conversion efficiency, Iam, Letid, Lid, PTC-to-STC, Temperature coefficient); Quality discipline high achiever (BOM verification); Reliability discipline high achiever (Sdml, Tc, Uvid, Budt, Damp heat, Hdt, Pid)

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

51.8 V

Voc when cold

per panel

33.4 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	2–11
Solis (Ginlong) S6-EH1P10K-H-US	600 V	80–520 V	datasheet	3–11
Solis (Ginlong) Solis-1P7.6K-4G-US	600 V	100–500 V	datasheet	3–11
Qcells Q.VOLT H7.6SX	498 V	234–498 V	CEC test window	8–9

Microinverters (one per panel)

Microinverter	Recommended module power	Max DC input	MPPT	Voc cold / Vmp hot	Check	DC/AC
Enphase IQ8PLUS-72-2-US	235–440 W	60 V	29–45 V	51.8 / 33.4 V	✓ Within range	1.45
Enphase IQ8X-80-M-US	320–540 W	79.5 V	43–60 V	51.8 / 33.4 V	✗ Not a match: module voltage below MPPT range	1.11
APsystems (Alt Power System) DS3-L	265–570 W	60 V	28–45 V	51.8 / 33.4 V	✓ Within range	0.54
Enphase IQ8M-72-2-US	260–460 W	60 V	30–45 V	51.8 / 33.4 V	✓ Within range	1.29
Enphase IQ8A-72-2-US	295–500 W	60 V	32–45 V	51.8 / 33.4 V	✓ Within range	1.2

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	704	11,967	6.08
Palmdale	1,835	771	13,102	6.69
Chula Vista	1,696	712	12,109	6.11
Huntington Beach	1,643	690	11,731	5.89
Riverside	1,696	712	12,109	6.21
Santa Clarita	1,724	724	12,309	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 420 W panels

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

Panel	Pmax	Efficiency	γ Pmax (CEC)	Voc, V	Isc, A	PVEL (product / brand)	SoCal permits (series)
Qcells Q.PEAK DUO L-G6.3/BFG 420	420 W	≈20.2%	−0.334	48.88	10.79	product 2022	—
LONGi LR5-54HABB-415M	415 W	≈21.8%	−0.342	37.77	13.94	brand 9× (2017–2026)	64
Canadian Solar CS3N-420MS	420 W	≥20.7%	−0.332	45.3	11.74	product 2023	46
Silfab Solar SIL-420QD	420 W	≈21.5%	−0.294	38.84	13.49	brand 7× (2017–2025)	39

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 Qcells

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

ManufacturerQcells
Listed in CEC asHanwha Qcells (Qidong) Co. Ltd., Qcells North America
Parent companyHanwha
Websiteq-cells.com
PVEL Top Performer (manufacturer)11 Scorecards (2016–2026)
RETC PV Module Index2023, 2024, 2025, 2026
Current panel series in CEC list81

Other series by SoCal permits

Q.PEAK DUO BLK ML-G10+ · 221Q.PEAK DUO BLK ML-G10.C+ · 124Q.TRON BLK M-G2+ · 40Q.TRON BLK M-G2.H+ · 33Q.TRON BLK M-G2.C+ · 24Q.TRON M-G2+ · 20

Questions & answers

How efficient is the Qcells Q.PEAK DUO L-G6.3/BFG 420?

Calculated from the panel area (2.08 m²): about 20.2% for the 420 W class. 420 W over 2.08 m² equals about 202 W per square meter.

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

PVWatts v8 with typical-year weather gives about 704 kWh per year per 420 W panel in Los Angeles and about 771 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.334 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 17.3% 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 2–11 panels per string (Voc at 2 °C = 51.8 V, Vmp at 74 °C cell = 33.4 V). Final design must follow the inverter manual and NEC 690.7.

Does it work with Enphase IQ8PLUS-72-2-US microinverters?

Voltage check against the Enphase datasheet: Voc when cold 51.8 V vs max input 60 V; Vmp when hot 33.4 V vs MPPT low 29 V; recommended module power 235–440 W. Confirm on the microinverter maker’s compatibility list.

Is it bifacial?

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

Has this panel been reliability-tested?

Q.PEAK DUO L-G6.3/BFG was a PVEL Top Performer in 2022 (LID+LETID, PAN, TC).

Sources

California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
Canadian Solar — manufacturer datasheet “HiKu Mono PERC CS3N-400|405|410|415|420|425MS MORE POWER”.
Silfab Solar — datasheet NTC SIL-420 QD CELL TECHNOLOGY.
Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists 2016–2026.
RETC — PV Module Index reports 2023–2026.
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 — APsystems (Alt Power System), Enphase, 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).