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78.5″ · 1,994 mm
39.4″ · 1,000 mm wide · 1.38″ (35 mm) frame · 50.7 lb (23 kg)
Solar panelQcells

Qcells Q.PLUS L-G4.2 345

72 cells (6 × 12). Power classes 320–350 W in the CEC list; datasheet covers 340–350 W.

CEC listed · Jan 21, 2020UL 170312-yr product + 25-yr performance warrantySeen in 1 SoCal permit
Power class
  • Power (STC)345 WCEC nameplate
  • Efficiency≥17.3%datasheet minimum
  • %/°C Pmax−0.40CEC test: −0.398
  • Output at year 2583%performance warranty

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · Qcells datasheet · 7 models
ModelPmaxVoc, VIsc, AVmp, VImp, AEfficiencyPTC
Q.PLUS L-G4.2 320320 W46.179.3936.398.79≈16.0%296 W
Q.PLUS L-G4.2 325325 W46.439.4436.708.85≈16.3%301 W
Q.PLUS L-G4.2 330330 W46.689.4937.028.91≈16.5%305 W
Q.PLUS L-G4.2 335335 W46.819.5437.338.97≈16.8%308 W
Q.PLUS L-G4.2 340340 W47.079.5937.639.03≥17.1%312 W
Q.PLUS L-G4.2 345345 W47.329.6437.939.09≥17.3%317 W
Q.PLUS L-G4.2 350350 W46.829.6438.209.16≥17.6%322 W
≈ efficiency = Pmax ÷ panel area 1.994 m² (datasheet size) for classes outside the datasheet.
CEC note: Formerly listed under Hanwha Q CELLS

Build & dimensions

Qcells datasheet · Cali-Graf calculation

Heat & cold behaviour

Qcells datasheet · CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation
DatasheetCEC listing test
Pmax coefficient γ−0.40 %/°C−0.398 %/°C
Voc coefficient β−0.29 %/°C−0.294 %/°C
Isc coefficient α+0.04 %/°C+0.050 %/°C
Vmp coefficient—−0.398 %/°C
Operating cell temperatureNMOT 43 ± 3 °CNOCT 45.2 °C

At normal operating conditions (NMOT, 800 W/m²) — datasheet

ClassPmax, WVoc, VIsc, AVmp, VImp, A
340 W253.443.517.6935.717.10
345 W257.143.747.7335.957.15
350 W260.943.977.7736.197.21

Away from lab conditions — CEC listing test points

ClassPmax at NOCTVmp × Imp at NOCTPmax at 200 W/m²Low-light efficiency vs STC
320 W236.2 W33.6 V × 7.03 A61 W95%
325 W239.5 W33.88 V × 7.07 A62.2 W96%
330 W243.4 W34.18 V × 7.12 A63.1 W96%
335 W243.7 W34.37 V × 7.09 A63.8 W95%
340 W251.4 W34.65 V × 7.25 A65.8 W97%
345 W255.1 W34.93 V × 7.3 A66.8 W97%
350 W254.6 W35.17 V × 7.24 A66.7 W95%
Pmax = Vmp × Imp from the CEC listing; low-light efficiency = Pmax at 200 W/m² ÷ (20% of STC Pmax).

Electrical & strength ratings

Qcells datasheet
Packaging: 29 per pallet

Certifications

CEC PV Module List (Oct 7, 2026) · Qcells datasheet
UL 1703IEC 61215IEC 61730Fire rating Type 1 (UL 61730)

Warranty & degradation

Qcells datasheet
75%81%88%94%100%051015202583% yr 25years
Straight line from 100% to the end-of-warranty value — linear, per datasheet.
  • Product warranty12 years
  • Performance warranty25 years, linear
  • Year 25≥ 83%

Independent reliability testing

Kiwa PVEL Scorecard · RETC PV Module Index
11
PVEL Scorecards
Qcells named Top Performer, 2016–2026
2023, 2026
RETC Overall Highest Achiever
Qcells, manufacturer level
This exact series is not listed in published PVEL Top Performer tables. Results below are for the manufacturer.

RETC PV Module Index — Qcells

YearRecognition
2023Overall Highest Achiever; High Achievement in Performance (Module efficiency, Pan file performance); High Achievement in Reliability (Damp heat test, Pid resistance, Thermal cycle test)
2024High Achievement in Performance
2025Performance High Achiever
2026Overall 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

Qcells datasheet · CEC PV Module List (Oct 7, 2026) · NLR PVWatts v8 · inverter datasheets · NLR SAM inverter library · CEC Grid Support Inverter List (Oct 7, 2026)
50.5 V
Voc when cold
per panel
30.5 V
Vmp when hot
per panel
11
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.

String inverters most named in SoCal permits

InverterMax DC inputMPPTWindow sourcePanels per string
Tesla 1538000-xx-y600 V60–480 Vdatasheet2–11
Solis (Ginlong) S6-EH1P10K-H-US600 V80–520 Vdatasheet3–11
Solis (Ginlong) Solis-1P7.6K-4G-US600 V100–500 Vdatasheet4–11
Qcells Q.VOLT H7.6SX498 V234–498 VCEC test window8–9

Microinverters (one per panel)

MicroinverterRecommended module powerMax DC inputMPPTVoc cold / Vmp hotCheckDC/AC
Enphase IQ8PLUS-72-2-US235–440 W60 V29–45 V50.5 / 30.5 V✓ Within range1.19
Enphase IQ8X-80-M-US320–540 W79.5 V43–60 V50.5 / 30.5 V✗ Not a match: module voltage below MPPT range0.91
APsystems (Alt Power System) DS3-L265–570 W60 V28–45 V50.5 / 30.5 V✓ Within range0.44
Enphase IQ8M-72-2-US260–460 W60 V30–45 V50.5 / 30.5 V✓ Within range1.06
Enphase IQ8A-72-2-US295–500 W60 V32–45 V50.5 / 30.5 V⚠ Works; below MPPT at peak heat0.99
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 Angeles1,67657811,5646.08
Palmdale1,83563312,6626.69
Chula Vista1,69658511,7026.11
Huntington Beach1,64356711,3375.89
Riverside1,69658511,7026.21
Santa Clarita1,72459511,8966.28
755Jan756Feb969Mar1,071Apr1,058May1,124Jun1,184Jul1,198Aug1,047Sep924Oct794Nov687DeckWh 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 345 W panels

CEC PV Module List (Oct 7, 2026) · Kiwa PVEL Scorecard · JinkoSolar datasheets · building permits
PanelPmaxEfficiencyγ Pmax (CEC)Voc, VIsc, APVEL (product / brand)SoCal permits (series)
Qcells Q.PLUS L-G4.2 345345 W≥17.3%−0.39847.329.64brand 11×1
LONGi LR4-60HPB-345M345 W≈19.5%−0.33940.211.06product 2021, 2022193
JinkoSolar JKM345M-60HBL345 W≈20.4%−0.40641.210.91brand 12× (2014–2026)45
REC Group REC345AA345 W≈20.5%−0.27943.410.12brand 9× (2016–2025)30
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

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.PLUS L-G4.2 345?

The Qcells datasheet guarantees at least 17.3% module efficiency for the 345 W class (up to 17.6% for 350 W). 345 W over 1.99 m² equals about 173 W per square meter.

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

PVWatts v8 with typical-year weather gives about 578 kWh per year per 345 W panel in Los Angeles and about 633 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.40 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 20.7% 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 = 50.5 V, Vmp at 74 °C cell = 30.5 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 50.5 V vs max input 60 V; Vmp when hot 30.5 V vs MPPT low 29 V; recommended module power 235–440 W. Confirm on the microinverter maker’s compatibility list.

What does the warranty cover?

12 years on the product and 25 years linear on performance: at least 83% after 25 years (manufacturer datasheet).

How big and heavy is it?

78.5 × 39.4 × 1.38 in (1,994 × 1,000 × 35 mm), 50.7 lb (23 kg).

Has this panel been reliability-tested?

This exact series is not in published PVEL Top Performer tables; Qcells was named a Top Performer in 11 Scorecards (2016–2026). RETC named Qcells Overall Highest Achiever in 2023, 2026.

Sources

  1. California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
  2. Qcells — manufacturer datasheet “Q.PLUS L-G4.2 340-350 Q.ANTUM SOLAR MODULE The Q.ANTUM solar module Q.PLUS L-G4.2 with power classes up to”.
  3. JinkoSolar — datasheet THE MOST DEPENDABLE SOLAR BRAND.
  4. JinkoSolar — manufacturer datasheet “Eagle HC 60M G2 315-335 Watt MONO PERC HALF CELL MODULE”.
  5. Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists 2016–2026.
  6. RETC — PV Module Index reports 2023–2026.
  7. NLR (formerly NREL) — System Advisor Model CEC inverter library (version 2026.7.3).
  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 — APsystems (Alt Power System), Enphase, Solis (Ginlong), Tesla (manufacturer documents).
  10. Building permits — Los Angeles County Public Works (EPIC-LA, unincorporated areas) (Jul 2020). Equipment matched from permit descriptions by model number.
  11. Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).