Illustration · 72 cells

Solar panelGCL System Integration Technol…

GCL System Integration Technology GCL-M6/72DH 375

Name: GCL System Integration Technology GCL-M6/72DH 375
Brand: GCL System Integration Technology

72 cells. Power classes 365–385 W in the CEC list.

CEC listed · Feb 11, 2020UL 61730

Power class

Power (STC)375 WCEC nameplate
Efficiency≈18.9%calculated from area
%/°C Pmax−0.398CEC listing test
PTC / STC92.6%PTC 347 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 5 models

Model	Pmax	Voc, V	Isc, A	Vmp, V	Imp, A	Efficiency	PTC	CEC listed
GCL-M6/72DH365	365 W	47.93	9.80	39.13	9.33	≈18.4%	338 W	Feb 11, 2020
GCL-M6/72DH370	370 W	48.13	9.88	39.32	9.41	≈18.7%	342 W	Feb 11, 2020
GCL-M6/72DH375	375 W	48.33	9.96	39.52	9.49	≈18.9%	347 W	Feb 11, 2020
GCL-M6/72DH380	380 W	48.53	10.04	39.72	9.57	≈19.2%	352 W	Feb 11, 2020
GCL-M6/72DH385	385 W	48.73	10.12	39.92	9.65	≈19.4%	357 W	Feb 11, 2020

≈ efficiency = Pmax ÷ CEC-listed area 1.98 m².

Heat & cold behaviour

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

	CEC listing test
Pmax coefficient γ	−0.398 %/°C
Voc coefficient β	−0.309 %/°C
Isc coefficient α	+0.033 %/°C
Operating cell temperature	NOCT 43.9 °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
365 W	268.9 W	35.08 V × 7.66 A	71.7 W	98%
370 W	272.5 W	35.25 V × 7.73 A	72.7 W	98%
375 W	276.2 W	35.43 V × 7.8 A	73.6 W	98%
380 W	279.9 W	35.61 V × 7.86 A	74.6 W	98%
385 W	283.7 W	35.79 V × 7.93 A	75.6 W	98%

Pmax = Vmp × Imp from the CEC listing; low-light efficiency = Pmax at 200 W/m² ÷ (20% of STC Pmax).

Certifications

CEC PV Module List (Oct 7, 2026)

UL 61730IEC 61215

UL 61730CEC listing
IEC 61215design qualification on file with CEC · Oct 29, 2019

Independent reliability testing

Kiwa PVEL Scorecard

PVEL Scorecards

GCL System Integration Technology named Top Performer, 2017–2026

This exact series is not listed in published PVEL Top Performer tables. Results below are for the manufacturer.

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

31.2 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	4–11
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 / 31.2 V	✓ Within range	1.29
Enphase IQ8X-80-M-US	320–540 W	79.5 V	43–60 V	51.8 / 31.2 V	✗ Not a match: module voltage below MPPT range	0.99
APsystems (Alt Power System) DS3-L	265–570 W	60 V	28–45 V	51.8 / 31.2 V	✓ Within range	0.48
Enphase IQ8M-72-2-US	260–460 W	60 V	30–45 V	51.8 / 31.2 V	✓ Within range	1.15
Enphase IQ8A-72-2-US	295–500 W	60 V	32–45 V	51.8 / 31.2 V	⚠ Works; below MPPT at peak heat	1.07

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	628	11,942	6.08
Palmdale	1,835	688	13,074	6.69
Chula Vista	1,696	636	12,084	6.11
Huntington Beach	1,643	616	11,706	5.89
Riverside	1,696	636	12,084	6.21
Santa Clarita	1,724	646	12,284	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 375 W panels

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

Panel	Pmax	Efficiency	γ Pmax (CEC)	Voc, V	Isc, A	PVEL (product / brand)	SoCal permits (series)
GCL System Integration Technology GCL-M6/72DH 375	375 W	≈18.9%	−0.398	48.33	9.96	brand 8×	—
Qcells Q.PEAK DUO BLK ML-G10+ 380	380 W	≈19.4%	−0.362	45.16	11.01	product 2022, 2023	221
LONGi LR4-60HPB-370M	370 W	≈20.9%	−0.339	41.2	11.5	product 2021, 2022	193
REC Group REC380AA Pure	380 W	≈21.2%	−0.256	48.4	10.17	brand 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.

Questions & answers

How efficient is the GCL System Integration Technology GCL-M6/72DH 375?

Calculated from the panel area (1.98 m²): about 18.9% for the 375 W class. 375 W over 1.98 m² equals about 189 W per square meter.

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

PVWatts v8 with typical-year weather gives about 628 kWh per year per 375 W panel in Los Angeles and about 688 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.398 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 20.6% 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 = 31.2 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 31.2 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; GCL System Integration Technology was named a Top Performer in 8 Scorecards (2017–2026).

Sources

California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
Qcells — manufacturer datasheet “Q.PEAK DUO BLK ML-G10+ ENDURING HIGH PERFORMANCE”.
Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists 2017–2026.
NLR (formerly NREL) — System Advisor Model CEC inverter library (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).