Illustration · 156 cells

Solar panelG-Star

G-Star GSD7S78T-630WT

Name: G-Star GSD7S78T-630WT
Brand: G-Star

156 cells. Power classes 610–655 W in the CEC list.

CEC listed · Mar 21, 2024UL 61730

Power class

Power (STC)630 WCEC nameplate
Efficiency≈22.7%calculated from area
%/°C Pmax−0.293CEC listing test
PTC / STC95.1%PTC 599 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 10 models

Model	Pmax	Voc, V	Isc, A	Vmp, V	Imp, A	Efficiency	PTC	CEC listed
GSD7S78T-610WT	610 W	56.02	13.61	47.04	12.97	≈22.0%	580 W	Mar 21, 2024
GSD7S78T-615WT	615 W	56.24	13.65	47.28	13.01	≈22.2%	585 W	Mar 21, 2024
GSD7S78T-620WT	620 W	56.46	13.69	47.51	13.05	≈22.4%	590 W	Mar 21, 2024
GSD7S78T-625WT	625 W	56.68	13.73	47.75	13.09	≈22.6%	595 W	Mar 21, 2024
GSD7S78T-630WT	630 W	56.90	13.77	47.99	13.13	≈22.7%	599 W	Mar 21, 2024
GSD7S78T-635WT	635 W	57.12	13.81	48.22	13.17	≈22.9%	604 W	Mar 21, 2024
GSD7S78T-640WT	640 W	57.34	13.85	48.48	13.21	≈23.1%	609 W	Mar 21, 2024
GSD7S78T-645WT	645 W	57.56	13.89	48.68	13.25	≈23.3%	614 W	Oct 1, 2025
GSD7S78T-650WT	650 W	57.78	13.93	48.91	13.29	≈23.5%	619 W	Oct 1, 2025
GSD7S78T-655WT	655 W	58.00	13.97	49.14	13.33	≈23.6%	624 W	Mar 11, 2026

≈ efficiency = Pmax ÷ CEC-listed area 2.77 m².

Build & dimensions

CEC PV Module List (Oct 7, 2026)

Module area2.77 m² (29.8 ft²)CEC-listed area
Cells156 cells
Back coverGlass (dual-glass module)

Heat & cold behaviour

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

	CEC listing test
Pmax coefficient γ	−0.293 %/°C
Voc coefficient β	−0.225 %/°C
Isc coefficient α	+0.044 %/°C
Operating cell temperature	NOCT 43.1 °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
610 W	466.7 W	45.12 V × 10.34 A	114.8 W	94%
615 W	470.5 W	45.35 V × 10.37 A	115.7 W	94%
620 W	474.2 W	45.57 V × 10.41 A	116.6 W	94%
625 W	478.1 W	45.8 V × 10.44 A	117.6 W	94%
630 W	482 W	46.03 V × 10.47 A	118.5 W	94%
635 W	485.7 W	46.25 V × 10.5 A	119.5 W	94%
640 W	489.9 W	46.5 V × 10.53 A	120.5 W	94%
645 W	493.4 W	46.7 V × 10.57 A	121.3 W	94%
650 W	497.2 W	46.92 V × 10.6 A	122.3 W	94%
655 W	501 W	47.14 V × 10.63 A	123.2 W	94%

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)

CityColdest air, °CHottest cell, °CString inverter

59.8 V

Voc when cold

per panel

40.1 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	2–10
Solis (Ginlong) S6-EH1P10K-H-US	600 V	80–520 V	datasheet	2–10
Solis (Ginlong) Solis-1P7.6K-4G-US	600 V	100–500 V	datasheet	3–10
Qcells Q.VOLT H7.6SX	498 V	234–498 V	CEC test window	6–8

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

PanelsCity for chartSystem size

City	kWh / kW / yr	kWh / panel / yr	kWh / system / yr	Sun, kWh/m²/day
Los Angeles	1,676	1,056	11,615	6.08
Palmdale	1,835	1,156	12,717	6.69
Chula Vista	1,696	1,068	11,753	6.11
Huntington Beach	1,643	1,035	11,386	5.89
Riverside	1,696	1,068	11,753	6.21
Santa Clarita	1,724	1,086	11,947	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 630 W panels

CEC PV Module List (Oct 7, 2026) · Kiwa PVEL Scorecard · datasheets

Panel	Pmax	Efficiency	γ Pmax (CEC)	Voc, V	Isc, A	PVEL (product / brand)
G-Star GSD7S78T-630WT	630 W	≈22.7%	−0.293	56.9	13.77	—
Canadian Solar CS7N-630MB-AG	630 W	≈20.5%	−0.390	44.2	18.23	product 2024
Hyundai Energy Solutions HiS-T630NJ	630 W	≈22.8%	−0.294	57.36	13.9	brand 5× (2017–2025)
Waaree BiN-17-630	630 W	≥22.5%	−0.308	57.02	13.94	product 2025, 2026

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 G-Star GSD7S78T-630WT?

Calculated from the panel area (2.77 m²): about 22.7% for the 630 W class. 630 W over 2.77 m² equals about 227 W per square meter.

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

PVWatts v8 with typical-year weather gives about 1,056 kWh per year per 630 W panel in Los Angeles and about 1,156 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.293 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 15.2% 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 2–10 panels per string (Voc at 2 °C = 59.8 V, Vmp at 74 °C cell = 40.1 V). Final design must follow the inverter manual and NEC 690.7.

Sources

California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
Hyundai Energy Solutions — datasheet [US] NJ(HiS) Series (N TOPCon Bifacial) 635~645W.
Waaree — datasheet ELITE SERIES BiN-17-615-645 WEL-EPD-615-645-156-BiN-HC-04-27.05.2024 35mm.
Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists.
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 — Solis (Ginlong), Tesla (manufacturer documents).
Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).