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Illustration · 144 half-cut cells
Solar panelSilfab Solar

Silfab Solar SIL-405HU

144 half-cut cells. Power classes 385–430 W in the CEC list.

CEC listed · Aug 3, 2020UL 61730
Power class
  • Power (STC)405 WCEC nameplate
  • Efficiency≈20.7%calculated from area
  • %/°C Pmax−0.325CEC listing test
  • PTC / STC93.9%PTC 380 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 10 models
ModelPmaxVoc, VIsc, AVmp, VImp, AEfficiencyPTCCEC listed
SIL-385HU385 W48.1110.0539.809.68≈19.6%361 WAug 3, 2020
SIL-390HU390 W48.3110.1340.029.75≈19.9%366 WAug 3, 2020
SIL-395HU395 W48.5110.2140.239.82≈20.2%371 WAug 3, 2020
SIL-400HU400 W48.7110.2840.459.89≈20.4%376 WAug 3, 2020
SIL-405HU405 W48.9110.3640.679.96≈20.7%380 WAug 3, 2020
SIL-410HU410 W49.1210.4440.8810.03≈20.9%385 WAug 3, 2020
SIL-415HU415 W49.3210.5241.1010.10≈21.2%390 WAug 3, 2020
SIL-420HU420 W49.5210.6041.3210.17≈21.4%395 WAug 3, 2020
SIL-425HU425 W49.7210.6741.5310.23≈21.7%400 WAug 3, 2020
SIL-430HU430 W49.9210.7541.7510.30≈21.9%404 WAug 3, 2020
≈ efficiency = Pmax ÷ CEC-listed area 1.96 m².

Build & dimensions

CEC PV Module List (Oct 7, 2026)

Heat & cold behaviour

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation
CEC listing test
Pmax coefficient γ−0.325 %/°C
Voc coefficient β−0.241 %/°C
Isc coefficient α+0.021 %/°C
Operating cell temperatureNOCT 44.6 °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
385 W275.6 W36.08 V × 7.64 A73.7 W96%
390 W279 W36.27 V × 7.69 A74.6 W96%
395 W282.5 W36.47 V × 7.75 A75.5 W96%
400 W286 W36.67 V × 7.8 A76.5 W96%
405 W289.6 W36.86 V × 7.86 A77.4 W96%
410 W293.1 W37.06 V × 7.91 A78.4 W96%
415 W296.7 W37.26 V × 7.96 A79.3 W96%
420 W300.3 W37.45 V × 8.02 A80.3 W96%
425 W303.9 W37.65 V × 8.07 A81.3 W96%
430 W307.6 W37.85 V × 8.13 A82.2 W96%
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
7
PVEL Scorecards
Silfab Solar named Top Performer, 2017–2025
4
RETC PV Module Index
Silfab Solar recognized 2023–2026
This exact series is not listed in published PVEL Top Performer tables. Results below are for the manufacturer.

RETC PV Module Index — Silfab Solar

YearRecognition
2023High Achievement in Performance (Ptc-to-stc ratio, LeTID RESISTANCE, Module efficiency)
2024High Achievement in Performance
2025Performance High Achiever
2026Performance discipline high achiever (Lid); Quality discipline high achiever (BOM verification); Reliability discipline high achiever (Pid, Sdml); 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)
51.6 V
Voc when cold
per panel
33.8 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. 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 Vdatasheet2–11
Solis (Ginlong) S6-EH1P10K-H-US600 V80–520 Vdatasheet3–11
Solis (Ginlong) Solis-1P7.6K-4G-US600 V100–500 Vdatasheet3–11
Qcells Q.VOLT H7.6SX498 V234–498 VCEC test window7–9

Microinverters (one per panel)

MicroinverterRecommended module powerMax DC inputMPPTVoc cold / Vmp hotCheckDC/AC
Enphase IQ8PLUS-72-2-US235–440 W60 V29–45 V51.6 / 33.8 V✓ Within range1.4
Enphase IQ8X-80-M-US320–540 W79.5 V43–60 V51.6 / 33.8 V✗ Not a match: module voltage below MPPT range1.07
APsystems (Alt Power System) DS3-L265–570 W60 V28–45 V51.6 / 33.8 V✓ Within range0.52
Enphase IQ8M-72-2-US260–460 W60 V30–45 V51.6 / 33.8 V✓ Within range1.25
Enphase IQ8A-72-2-US295–500 W60 V32–45 V51.6 / 33.8 V✓ Within range1.16
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 Angeles1,67667911,5396.08
Palmdale1,83574312,6346.69
Chula Vista1,69668711,6776.11
Huntington Beach1,64366511,3125.89
Riverside1,69668711,6776.21
Santa Clarita1,72469811,8706.28
753Jan754Feb967Mar1,069Apr1,055May1,122Jun1,181Jul1,195Aug1,045Sep922Oct792Nov686DeckWh 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 405 W panels

CEC PV Module List (Oct 7, 2026) · Qcells datasheet · Kiwa PVEL Scorecard · building permits
PanelPmaxEfficiencyγ Pmax (CEC)Voc, VIsc, APVEL (product / brand)SoCal permits (series)
Silfab Solar SIL-405HU405 W≈20.7%−0.32548.9110.36brand 7×—
Qcells Q.PEAK DUO BLK ML-G10+ 405405 W≥20.6%−0.36245.3411.17product 2022, 2023221
JA Solar JAM54S31-405/MR405 W≈21.3%−0.32937.2313.87product 2023, 2024152
REC Group REC405AA Pure405 W≈22.6%−0.25648.910.3brand 9× (2016–2025)66
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 Silfab Solar

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

Other series by SoCal permits

SIL-xxxQD · 39SIL-xxxHC+ · 28SIL-xxxBK · 10SIL-xxxHC · 9SIL-xxxNX · 6SIL-xxxBG · 5

Questions & answers

How efficient is the Silfab Solar SIL-405HU?

Calculated from the panel area (1.96 m²): about 20.7% for the 405 W class. 405 W over 1.96 m² equals about 207 W per square meter.

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

PVWatts v8 with typical-year weather gives about 679 kWh per year per 405 W panel in Los Angeles and about 743 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.325 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 16.8% 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 = 51.6 V, Vmp at 74 °C cell = 33.8 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 51.6 V vs max input 60 V; Vmp when hot 33.8 V vs MPPT low 29 V; recommended module power 235–440 W. Confirm on the microinverter maker’s compatibility list.

Has this panel been reliability-tested?

This exact series is not in published PVEL Top Performer tables; Silfab Solar was named a Top Performer in 7 Scorecards (2017–2025).

Sources

  1. California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
  2. Qcells — manufacturer datasheet “Q.PEAK DUO BLK ML-G10+ ENDURING HIGH PERFORMANCE”.
  3. Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists 2017–2025.
  4. RETC — PV Module Index reports 2023–2026.
  5. NLR (formerly NREL) — System Advisor Model CEC inverter library (version 2026.7.3).
  6. NLR (formerly NREL) — PVWatts v8, NSRDB PSM v3 typical-year weather for Los Angeles, Palmdale, Chula Vista, Huntington Beach, Riverside, Santa Clarita.
  7. Inverter datasheets — APsystems (Alt Power System), Enphase, Solis (Ginlong), Tesla (manufacturer documents).
  8. Building permits — Southern California permit portals. Equipment matched from permit descriptions.
  9. Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).