Illustration · 144 half-cut cells

Solar panelSuntech

Suntech STP390S-A72U/Vfh

Name: Suntech STP390S-A72U/Vfh
Brand: Suntech

144 half-cut cells. Power classes 370–415 W in the CEC list.

CEC listed · Oct 12, 2020UL 61730

Power class

Power (STC)390 WCEC nameplate
Efficiency≈19.6%calculated from area
%/°C Pmax−0.340CEC listing test
PTC / STC93.2%PTC 364 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
STP370S-A72U/Vfh	370 W	47.80	10.05	40.60	9.12	≈18.6%	344 W	Oct 12, 2020
STP375S-A72U/Vfh	375 W	48.00	10.12	40.80	9.20	≈18.8%	349 W	Oct 12, 2020
STP380S-A72U/Vfh	380 W	48.20	10.19	41.00	9.27	≈19.1%	354 W	Oct 12, 2020
STP385S-A72U/Vfh	385 W	48.40	10.26	41.20	9.35	≈19.3%	359 W	Oct 12, 2020
STP390S-A72U/Vfh	390 W	48.60	10.33	41.40	9.43	≈19.6%	364 W	Oct 12, 2020
STP395S-A72U/Vfh	395 W	48.80	10.40	41.60	9.50	≈19.8%	368 W	Oct 12, 2020
STP400S-A72U/Vfh	400 W	49.00	10.47	41.80	9.57	≈20.1%	373 W	Oct 12, 2020
STP405S-A72U/Vfh	405 W	49.20	10.54	42.00	9.65	≈20.4%	378 W	Oct 12, 2020
STP410S-A72U/Vfh	410 W	49.40	10.61	42.20	9.72	≈20.6%	383 W	Oct 12, 2020
STP415S-A72U/Vfh	415 W	49.60	10.68	42.40	9.79	≈20.9%	388 W	Oct 12, 2020

≈ efficiency = Pmax ÷ CEC-listed area 1.99 m².

Build & dimensions

CEC PV Module List (Oct 7, 2026)

Module area1.99 m² (21.4 ft²)CEC-listed area
Cells144 half-cut cells
Back coverWhite backsheet

Heat & cold behaviour

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

	CEC listing test
Pmax coefficient γ	−0.340 %/°C
Voc coefficient β	−0.263 %/°C
Isc coefficient α	+0.033 %/°C
Operating cell temperature	NOCT 45.5 °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
370 W	275.8 W	37.3 V × 7.39 A	71 W	96%
375 W	279.6 W	37.48 V × 7.46 A	71.9 W	96%
380 W	283.1 W	37.67 V × 7.52 A	72.8 W	96%
385 W	286.9 W	37.85 V × 7.58 A	73.8 W	96%
390 W	290.8 W	38.03 V × 7.65 A	74.8 W	96%
395 W	294.3 W	38.22 V × 7.7 A	75.7 W	96%
400 W	297.9 W	38.4 V × 7.76 A	76.7 W	96%
405 W	301.9 W	38.58 V × 7.82 A	77.7 W	96%
410 W	305.5 W	38.77 V × 7.88 A	78.6 W	96%
415 W	309.2 W	38.95 V × 7.94 A	79.6 W	96%

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

PVEL Scorecards

Suntech named Top Performer, 2014–2024

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

51.5 V

Voc when cold

per panel

33.9 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	3–11
Qcells Q.VOLT H7.6SX	498 V	234–498 V	CEC test window	7–9

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	51.5 / 33.9 V	✓ Within range	1.34
Enphase IQ8X-80-M-US	320–540 W	79.5 V	43–60 V	51.5 / 33.9 V	✗ Not a match: module voltage below MPPT range	1.03
APsystems (Alt Power System) DS3-L	265–570 W	60 V	28–45 V	51.5 / 33.9 V	✓ Within range	0.5
Enphase IQ8M-72-2-US	260–460 W	60 V	30–45 V	51.5 / 33.9 V	✓ Within range	1.2
Enphase IQ8A-72-2-US	295–500 W	60 V	32–45 V	51.5 / 33.9 V	✓ Within range	1.12

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	654	11,766	6.08
Palmdale	1,835	716	12,882	6.69
Chula Vista	1,696	661	11,906	6.11
Huntington Beach	1,643	641	11,534	5.89
Riverside	1,696	661	11,906	6.21
Santa Clarita	1,724	672	12,102	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 390 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)
Suntech STP390S-A72U/Vfh	390 W	≈19.6%	−0.340	48.6	10.33	brand 6×	—
Qcells Q.PEAK DUO BLK ML-G10+ 390	390 W	≥19.9%	−0.362	45.23	11.07	product 2022, 2023	221
JA Solar JAM54S31-390/MR	390 W	≈20.5%	−0.329	36.85	13.61	product 2023, 2024	152
REC Group REC390AA Pure	390 W	≈21.8%	−0.256	48.6	10.19	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 Suntech STP390S-A72U/Vfh?

Calculated from the panel area (1.99 m²): about 19.6% for the 390 W class. 390 W over 1.99 m² equals about 196 W per square meter.

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

PVWatts v8 with typical-year weather gives about 654 kWh per year per 390 W panel in Los Angeles and about 716 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.340 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 17.6% 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 = 51.5 V, Vmp at 74 °C cell = 33.9 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 51.5 V vs max input 60 V; Vmp when hot 33.9 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; Suntech was named a Top Performer in 6 Scorecards (2014–2024).

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 2014–2024.
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).