Illustration · 120 half-cut cells

Solar panelSuntech

Suntech STP370S-B60/Wnhb

Name: Suntech STP370S-B60/Wnhb
Brand: Suntech

120 half-cut cells. Power classes 355–375 W in the CEC list.

CEC listed · Jul 1, 2021UL 61730Seen in 2 SoCal permits

Power class

Power (STC)370 WCEC nameplate
Efficiency≈20.3%calculated from area
%/°C Pmax−0.375CEC listing test
PTC / STC93.5%PTC 346 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
STP355S-B60/Wnhb	355 W	41.30	11.08	33.80	10.51	≈19.5%	331 W	Jul 1, 2021
STP360S-B60/Wnhb	360 W	41.50	11.15	34.00	10.59	≈19.8%	336 W	Jul 1, 2021
STP365S-B60/Wnhb	365 W	41.70	11.22	34.20	10.68	≈20.1%	341 W	Jul 1, 2021
STP370S-B60/Wnhb	370 W	41.90	11.29	34.40	10.76	≈20.3%	346 W	Mar 21, 2022
STP375S-B60/Wnhb	375 W	42.10	11.36	34.60	10.84	≈20.6%	351 W	Mar 21, 2022

≈ efficiency = Pmax ÷ CEC-listed area 1.82 m².

Build & dimensions

CEC PV Module List (Oct 7, 2026)

Module area1.82 m² (19.6 ft²)CEC-listed area
Cells120 half-cut cells
Back coverBlack backsheet

Heat & cold behaviour

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

	CEC listing test
Pmax coefficient γ	−0.375 %/°C
Voc coefficient β	−0.281 %/°C
Isc coefficient α	+0.067 %/°C
Operating cell temperature	NOCT 43.2 °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
355 W	269.2 W	32.07 V × 8.39 A	68.5 W	96%
360 W	272.8 W	32.26 V × 8.46 A	69.4 W	96%
365 W	276.8 W	32.45 V × 8.53 A	70.4 W	96%
370 W	280.5 W	32.64 V × 8.59 A	71.3 W	96%
375 W	284.2 W	32.83 V × 8.66 A	72.3 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

44.6 V

Voc when cold

per panel

26.9 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	3–13
Solis (Ginlong) S6-EH1P10K-H-US	600 V	80–520 V	datasheet	3–13
Solis (Ginlong) Solis-1P7.6K-4G-US	600 V	100–500 V	datasheet	4–13
Qcells Q.VOLT H7.6SX	498 V	234–498 V	CEC test window	9–11

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	44.6 / 26.9 V	⚠ Works; below MPPT at peak heat	1.28
Enphase IQ8X-80-M-US	320–540 W	79.5 V	43–60 V	44.6 / 26.9 V	✗ Not a match: module voltage below MPPT range	0.97
APsystems (Alt Power System) DS3-L	265–570 W	60 V	28–45 V	44.6 / 26.9 V	⚠ Works; below MPPT at peak heat	0.47
Enphase IQ8M-72-2-US	260–460 W	60 V	30–45 V	44.6 / 26.9 V	⚠ Works; below MPPT at peak heat	1.14
Enphase IQ8A-72-2-US	295–500 W	60 V	32–45 V	44.6 / 26.9 V	⚠ Works; below MPPT at peak heat	1.06

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	620	11,782	6.08
Palmdale	1,835	679	12,900	6.69
Chula Vista	1,696	628	11,923	6.11
Huntington Beach	1,643	608	11,550	5.89
Riverside	1,696	628	11,923	6.21
Santa Clarita	1,724	638	12,120	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 370 W panels

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

Panel	Pmax	Efficiency	γ Pmax (CEC)	Voc, V	Isc, A	PVEL (product / brand)	SoCal permits (series)
Suntech STP370S-B60/Wnhb	370 W	≈20.3%	−0.375	41.9	11.29	brand 6×	2
LONGi LR4-60HPB-370M	370 W	≈20.9%	−0.339	41.2	11.5	product 2021, 2022	193
Canadian Solar CS3N-375MS {Blk}	375 W	≈19%	−0.342	43.5	11.2	product 2023	46
REC Group REC370AA	370 W	≈21.9%	−0.258	44.1	10.55	brand 9× (2016–2025)	30

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 STP370S-B60/Wnhb?

Calculated from the panel area (1.82 m²): about 20.3% for the 370 W class. 370 W over 1.82 m² equals about 203 W per square meter.

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

PVWatts v8 with typical-year weather gives about 620 kWh per year per 370 W panel in Los Angeles and about 679 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.375 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 19.4% 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 3–13 panels per string (Voc at 2 °C = 44.6 V, Vmp at 74 °C cell = 26.9 V). Final design must follow the inverter manual and NEC 690.7.

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).
Canadian Solar — manufacturer datasheet “HiKu Mono PERC CS3N-400|405|410|415|420|425MS MORE POWER”.
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 — Los Angeles County Public Works (EPIC-LA, unincorporated areas) (Sep 2022 – Oct 2022). Equipment matched from permit descriptions by model number.
Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).