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Illustration · 132 half-cut cells
Solar panelSunpal Power

Sunpal Power SP660M-66H

132 half-cut cells. Power classes 630–690 W in the CEC list.

CEC listed · Aug 21, 2023UL 61730
Power class
  • Power (STC)660 WCEC nameplate
  • Efficiency≈21.2%calculated from area
  • %/°C Pmax−0.351CEC listing test
  • PTC / STC93.2%PTC 615 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 13 models
ModelPmaxVoc, VIsc, AVmp, VImp, AEfficiencyPTCCEC listed
SP630M-66H630 W44.5018.2336.6017.22≈20.3%586 WAug 21, 2023
SP635M-66H635 W44.7018.2836.8017.26≈20.4%591 WAug 21, 2023
SP640M-66H640 W44.9018.3337.0017.30≈20.6%596 WAug 21, 2023
SP645M-66H645 W45.1018.3837.2017.34≈20.7%601 WAug 21, 2023
SP650M-66H650 W45.3018.4337.4017.39≈20.9%605 WAug 21, 2023
SP655M-66H655 W45.5018.4837.6017.43≈21.1%610 WAug 21, 2023
SP660M-66H660 W45.7018.5337.8017.47≈21.2%615 WAug 21, 2023
SP665M-66H665 W45.9018.5838.0017.50≈21.4%620 WAug 21, 2023
SP670M-66H670 W46.1018.6338.2017.54≈21.5%625 WAug 21, 2023
SP675M-66H675 W46.3018.6838.4017.58≈21.7%629 WAug 21, 2023
SP680M-66H680 W46.5018.7338.6017.62≈21.9%634 WAug 21, 2023
SP685M-66H685 W46.7018.7838.8017.66≈22.0%639 WAug 21, 2023
SP690M-66H690 W46.9018.8339.0017.70≈22.2%644 WAug 21, 2023
≈ efficiency = Pmax ÷ CEC-listed area 3.11 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−0.351 %/°C
Voc coefficient β−0.286 %/°C
Isc coefficient α+0.065 %/°C
Operating cell temperatureNOCT 45.6 °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
630 W478.3 W34.18 V × 13.99 A123.2 W98%
635 W482.1 W34.37 V × 14.03 A124.2 W98%
640 W485.8 W34.56 V × 14.06 A125.2 W98%
645 W489.6 W34.74 V × 14.09 A126.1 W98%
650 W493.6 W34.93 V × 14.13 A127.2 W98%
655 W497.4 W35.12 V × 14.16 A128.2 W98%
660 W501.2 W35.3 V × 14.2 A129.1 W98%
665 W504.7 W35.49 V × 14.22 A130 W98%
670 W508.5 W35.68 V × 14.25 A131 W98%
675 W512.4 W35.87 V × 14.29 A132 W98%
680 W516.2 W36.05 V × 14.32 A133 W98%
685 W520 W36.24 V × 14.35 A134 W98%
690 W523.9 W36.43 V × 14.38 A135 W98%
Pmax = Vmp × Imp from the CEC listing; low-light efficiency = Pmax at 200 W/m² ÷ (20% of STC Pmax).

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)
48.7 V
Voc when cold
per panel
30.1 V
Vmp when hot
per panel
12
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 Vdatasheet2–12
Solis (Ginlong) S6-EH1P10K-H-US600 V80–520 Vdatasheet3–12
Solis (Ginlong) Solis-1P7.6K-4G-US600 V100–500 Vdatasheet4–12
Qcells Q.VOLT H7.6SX498 V234–498 VCEC test window8–10

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
CitykWh / kW / yrkWh / panel / yrkWh / system / yrSun, kWh/m²/day
Los Angeles1,6761,10612,1686.08
Palmdale1,8351,21113,3226.69
Chula Vista1,6961,11912,3136.11
Huntington Beach1,6431,08411,9285.89
Riverside1,6961,11912,3136.21
Santa Clarita1,7241,13812,5166.28
794Jan795Feb1,020Mar1,127Apr1,113May1,183Jun1,246Jul1,260Aug1,102Sep972Oct836Nov723DeckWh 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.

Questions & answers

How efficient is the Sunpal Power SP660M-66H?

Calculated from the panel area (3.11 m²): about 21.2% for the 660 W class. 660 W over 3.11 m² equals about 212 W per square meter.

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

PVWatts v8 with typical-year weather gives about 1,106 kWh per year per 660 W panel in Los Angeles and about 1,211 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.351 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 18.2% 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 2–12 panels per string (Voc at 2 °C = 48.7 V, Vmp at 74 °C cell = 30.1 V). Final design must follow the inverter manual and NEC 690.7.

Sources

  1. California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
  2. NLR (formerly NREL) — System Advisor Model CEC inverter library (version 2026.7.3).
  3. NLR (formerly NREL) — PVWatts v8, NSRDB PSM v3 typical-year weather for Los Angeles, Palmdale, Chula Vista, Huntington Beach, Riverside, Santa Clarita.
  4. Inverter datasheets — Solis (Ginlong), Tesla (manufacturer documents).
  5. Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).