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82.6″ · 2,098 mm
44.6″ · 1,133 mm wide · 1.38″ (35 mm) frame · 57.8 lb (26.2 kg)
Solar panelSilfab Solar

Silfab Solar SIL-520QM

132 cells, N-type. Power classes 510–540 W in the CEC list.

CEC listed · Jul 1, 2024UL 6173025-yr product + 30-yr performance warrantyN-type
Power class
  • Power (STC)520 WCEC nameplate
  • Efficiency≈21.9%calculated from area
  • %/°C Pmax−0.29CEC test: −0.296
  • Output at year 3089.3%performance warranty

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 7 models
ModelPmaxVoc, VIsc, AVmp, VImp, AEfficiencyPTCCEC listed
SIL-510QM510 W47.3013.5939.9212.78≈21.5%483 WJul 1, 2024
SIL-515QM515 W47.4113.6240.2012.81≈21.7%487 WJul 1, 2024
SIL-520QM520 W47.5213.6540.4812.85≈21.9%492 WJul 1, 2024
SIL-525QM525 W47.6313.6840.7712.88≈22.1%497 WJul 1, 2024
SIL-530QM530 W47.7413.7141.0512.91≈22.3%502 WJul 1, 2024
SIL-535QM535 W47.8513.7441.3412.95≈22.5%507 WJul 1, 2024
SIL-540QM540 W47.9613.7741.6312.97≈22.7%512 WJul 1, 2024
≈ efficiency = Pmax ÷ panel area 2.377 m² (datasheet size).

Build & dimensions

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

Heat & cold behaviour

Silfab Solar datasheet · CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation
DatasheetCEC listing test
Pmax coefficient γ−0.29 %/°C−0.296 %/°C
Voc coefficient β−0.24 %/°C−0.242 %/°C
Isc coefficient α+0.04 %/°C+0.032 %/°C
Vmp coefficient≈ −0.33 %/°C—
Operating cell temperatureNMOT 45 °CNOCT 44.6 °C
Vmp coefficient ≈ γ − α (datasheet); used only for the hot-roof voltage estimate.

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

ClassPmax, WVoc, VIsc, AVmp, VImp, A
520 W384.043.7110.9637.2410.31

Away from lab conditions — CEC listing test points

ClassPmax at NOCTVmp × Imp at NOCTPmax at 200 W/m²Low-light efficiency vs STC
510 W384.3 W36.48 V × 10.53 A96.3 W94%
515 W388 W36.74 V × 10.56 A97.2 W94%
520 W391.8 W37 V × 10.59 A98.2 W94%
525 W395.5 W37.26 V × 10.61 A99.1 W94%
530 W399.3 W37.52 V × 10.64 A100 W94%
535 W403.1 W37.79 V × 10.67 A101 W94%
540 W406.8 W38.05 V × 10.69 A101.9 W94%
Pmax = Vmp × Imp from the CEC listing; low-light efficiency = Pmax at 200 W/m² ÷ (20% of STC Pmax).

Electrical & strength ratings

Silfab Solar datasheet
Packaging: 29 per pallet

Certifications

CEC PV Module List (Oct 7, 2026) · Silfab Solar datasheet
UL 61730IEC 61215IEC 61730IEC 61701IEC 62716IEC 62790ISO 9001

Warranty & degradation

Silfab Solar datasheet

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

Silfab Solar datasheet · Cali-Graf calculation · NLR PVWatts v8 · CEC PV Module List (Oct 7, 2026) · inverter datasheets · NLR SAM inverter library · CEC Grid Support Inverter List (Oct 7, 2026)
50.1 V
Voc when cold
per panel
33.9 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 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 IQ8X-80-M-US320–540 W79.5 V43–60 V50.1 / 33.9 V✗ Not a match: module voltage below MPPT range1.37
APsystems (Alt Power System) DS3-L265–570 W60 V28–45 V50.1 / 33.9 V✓ Within range0.67
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 Angeles1,67687211,3306.08
Palmdale1,83595412,4056.69
Chula Vista1,69688211,4656.11
Huntington Beach1,64385411,1075.89
Riverside1,69688211,4656.21
Santa Clarita1,72489611,6546.28
740Jan740Feb950Mar1,049Apr1,036May1,101Jun1,160Jul1,174Aug1,026Sep905Oct778Nov673DeckWh 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 520 W panels

CEC PV Module List (Oct 7, 2026) · datasheets · Kiwa PVEL Scorecard · building permits
PanelPmaxEfficiencyγ Pmax (CEC)Voc, VIsc, ASizePVEL (product / brand)SoCal permits (series)
Silfab Solar SIL-520QM520 W≈21.9%−0.29647.5213.6582.6 × 44.6 inbrand 7×—
SEG Solar SEG-520-BTD-BG520 W≈26.6%−0.29040.916.1367.8 × 44.6 inproduct 2023, 2024, 2025, 20268
Canadian Solar CS6W-520MB-AG520 W≈20.2%−0.32448.413.789.2 × 44.6 inproduct 20241
LONGi LR5-72HBD-520M520 W≈20.3%−0.32348.913.5788.8 × 44.6 inproduct 20261
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.

Documents

manufacturer documents

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-520QM?

Calculated from the panel area (2.38 m²): about 21.9% for the 520 W class. 520 W over 2.38 m² equals about 219 W per square meter.

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

PVWatts v8 with typical-year weather gives about 872 kWh per year per 520 W panel in Los Angeles and about 954 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.29 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 15% 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 = 50.1 V, Vmp at 74 °C cell = 33.9 V). Final design must follow the inverter manual and NEC 690.7.

Does it work with APsystems (Alt Power System) DS3-L microinverters?

Voltage check against the APsystems (Alt Power System) datasheet: Voc when cold 50.1 V vs max input 60 V; Vmp when hot 33.9 V vs MPPT low 28 V; recommended module power 265–570 W. Confirm on the microinverter maker’s compatibility list.

What does the warranty cover?

25 years on the product and 30 years on performance: at least 89.3% after 30 years (manufacturer datasheet).

How big and heavy is it?

82.6 × 44.6 × 1.38 in (2,098 × 1,133 × 35 mm), 57.8 lb (26.2 kg).

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. Silfab Solar — datasheet NTC SIL-520 QM CELL TECHNOLOGY.
  3. SEG Solar — manufacturer datasheet “XXXTFHTPMBSDPN YUKON/Series )BMG$FMM/5ZQF501$PO”.
  4. Canadian Solar — datasheet BiHiKu6 BIFACIAL MONO PERC CS6W-520|525|530|535|540|545|550MB-AG.
  5. LONGi — manufacturer datasheet “LR5-72HBD Suitable for distributed projects Advanced module technology delivers superior”.
  6. Silfab Solar — document library on the manufacturer’s website (links above).
  7. Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists 2017–2025.
  8. RETC — PV Module Index reports 2023–2026.
  9. NLR (formerly NREL) — System Advisor Model CEC inverter library (version 2026.7.3).
  10. NLR (formerly NREL) — PVWatts v8, NSRDB PSM v3 typical-year weather for Los Angeles, Palmdale, Chula Vista, Huntington Beach, Riverside, Santa Clarita.
  11. Inverter datasheets — APsystems (Alt Power System), Enphase, Solis (Ginlong), Tesla (manufacturer documents).
  12. Building permits — Southern California permit portals. Equipment matched from permit descriptions.
  13. Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).