Illustration · 108 half-cut cells

Solar panelJA Solar

JA Solar JAM54S31-395/MR

Name: JA Solar JAM54S31-395/MR
Brand: JA Solar

108 half-cut cells. Power classes 385–405 W in the CEC list.

CEC listed · Oct 11, 2021UL 61730PVEL Top Performer 2023, 2024Installed in 152 SoCal permits

Power class

Power (STC)395 WCEC nameplate
Efficiency≈20.8%calculated from area
%/°C Pmax−0.329CEC listing test
PTC / STC93.3%PTC 369 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
JAM54S31-385/MR	385 W	36.71	13.52	30.46	12.64	≈20.3%	359 W	Oct 11, 2021
JAM54S31-390/MR	390 W	36.85	13.61	30.64	12.73	≈20.5%	364 W	Oct 11, 2021
JAM54S31-395/MR	395 W	36.98	13.70	30.84	12.81	≈20.8%	369 W	Oct 11, 2021
JAM54S31-400/MR	400 W	37.07	13.79	31.01	12.90	≈21.1%	374 W	Oct 11, 2021
JAM54S31-405/MR	405 W	37.23	13.87	31.21	12.98	≈21.3%	378 W	Oct 11, 2021

≈ efficiency = Pmax ÷ CEC-listed area 1.9 m².

Build & dimensions

CEC PV Module List (Oct 7, 2026)

Module area1.9 m² (20.5 ft²)CEC-listed area
Cells108 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	−0.329 %/°C
Voc coefficient β	−0.259 %/°C
Isc coefficient α	+0.045 %/°C
Operating cell temperature	NOCT 46.2 °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
385 W	287.5 W	28.71 V × 10.02 A	74.1 W	96%
390 W	291.3 W	28.88 V × 10.09 A	75.1 W	96%
395 W	295 W	29.07 V × 10.15 A	76.1 W	96%
400 W	298.7 W	29.23 V × 10.22 A	77 W	96%
405 W	302.5 W	29.42 V × 10.29 A	78 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 · RETC PV Module Index

2023, 2024

PVEL Top Performer

this series

Tests passed as Top Performer

HSS, LID+LETID, TC

PVEL Scorecards

JA Solar named Top Performer, 2014–2026

2023, 2024, 2025, 2026

RETC Overall Highest Achiever

JA Solar, manufacturer level

PVEL Top Performer tests

Year	Product	Tests
2023	JAM54S31-xxx/MR	LID+LETID
2024	JAM54S31-xxx/MR	HSSLID+LETIDTC

Tested bill of materials

PVEL-tested factoryChina
Cell technology (tested BOM)p-type PERC
Module design (tested BOM)monofacial - glass//backsheet
Power class range tested380-425W
Hail test ice ball50 mm

Details describe the tested sample, not every module of the series.

RETC PV Module Index — JA Solar

Year	Recognition
2023	Overall Highest Achiever; High Achievement in Performance (Ptc-to-stc ratio, Pan file performance, Module efficiency, LeTID RESISTANCE); High Achievement in Quality (Hail durability test, Thresher test); High Achievement in Reliability (Thermal cycle test, SDML, Pid resistance, Damp heat test)
2024	Overall Highest Achiever
2025	Overall Highest Achiever
2026	Overall Highest Achiever; High achievement in performance; High achievement in reliability; Performance discipline high achiever (Conversion efficiency, Iam, Letid, Lid, PAN file, PTC-to-STC, Temperature coefficient); Quality discipline high achiever (BOM verification); Reliability discipline high achiever (Damp heat, Pid, Sdml, Tc)

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

39.2 V

Voc when cold

per panel

25.2 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	3–15
Solis (Ginlong) S6-EH1P10K-H-US	600 V	80–520 V	datasheet	4–15
Solis (Ginlong) Solis-1P7.6K-4G-US	600 V	100–500 V	datasheet	4–15
Qcells Q.VOLT H7.6SX	498 V	234–498 V	CEC test window	10–12

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	39.2 / 25.2 V	⚠ Works; below MPPT at peak heat	1.36
Enphase IQ8X-80-M-US	320–540 W	79.5 V	43–60 V	39.2 / 25.2 V	✗ Not a match: module voltage below MPPT range	1.04
APsystems (Alt Power System) DS3-L	265–570 W	60 V	28–45 V	39.2 / 25.2 V	⚠ Works; below MPPT at peak heat	0.51
Enphase IQ8M-72-2-US	260–460 W	60 V	30–45 V	39.2 / 25.2 V	⚠ Works; below MPPT at peak heat	1.22
Enphase IQ8A-72-2-US	295–500 W	60 V	32–45 V	39.2 / 25.2 V	✗ Not a match: module voltage below MPPT range	1.13

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	662	11,916	6.08
Palmdale	1,835	725	13,047	6.69
Chula Vista	1,696	670	12,059	6.11
Huntington Beach	1,643	649	11,682	5.89
Riverside	1,696	670	12,059	6.21
Santa Clarita	1,724	681	12,258	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.

Who installs JAM54S31-xxx/MR panels in SoCal

building permits · CSLB License Master

152

Permits naming this series

Aug 2021 – Jan 2026

Licensed installers

CSLB license on the permit

Jurisdictions so far

LA County (unincorp.) (131), Palmdale (19), Huntington Beach (2)

Bright Ops

Worcester · CSLB #1020761

9 installsAug 2025 – Nov 2025Palmdale

Sunrun

Lehi · CSLB #750184

6 installsDec 2023 – Jun 2025Palmdale, Huntington Beach

Homelink Solar

Chino · CSLB #1117534

4 installsOct 2025 – Jan 2026Palmdale

South West Builders

Simi Valley · CSLB #1012298

1 installOct 2025Palmdale

Permits over time

Power class named in permit

395 W

405 W

400 W

390 W

Top ZIP codes

ZIP 9060427
ZIP 9138424
ZIP 9355013
ZIP 906069
ZIP 906058
ZIP 913117
ZIP 917247
ZIP 913616
Other ZIP codes11

Typical system

median 6.5 kW, 16 panels (n = 140)

Only installer and ZIP level is shown — no homeowner names, street addresses or permit numbers. Permits from LA County (unincorp.) come without a contractor license, so they count toward totals but not toward installers. Counts grow as more permit portals are loaded.

Installed together with

building permits

Microinverters

Enphase IQ8+

Power Center Dxxx-M2

Inverters

SolarEdge SE…H (HD-Wave)

Delta Electronics Ex-TL-US

Growatt MIN xxxxTL-XH-US

SolarEdge (model not specified)

Delta Electronics (model not specified)

Optimizers

SolarEdge Power Optimizer

Batteries

Tesla Powerwall 3

Tesla Powerwall

SolarEdge Home Battery

Tesla Powerwall 3 Expansion

LG Energy Solution RESU 10H Prime

Number of permits naming both this panel series and the product; 149 of 152 permits list other equipment.

Compare with similar 395 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)
JA Solar JAM54S31-395/MR	395 W	≈20.8%	−0.329	36.98	13.7	product 2023, 2024	152
Qcells Q.PEAK DUO BLK ML-G10+ 395	395 W	≥20.1%	−0.362	45.27	11.1	product 2022, 2023	221
REC Group REC395AA Pure	395 W	≈22%	−0.256	48.7	10.2	brand 9× (2016–2025)	66
LONGi LR5-54HABB-395M	395 W	≈20.8%	−0.342	36.81	13.65	brand 9× (2017–2026)	64

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.

About JA Solar

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

ManufacturerJA Solar
Listed in CEC asJA Solar
PVEL Top Performer (manufacturer)11 Scorecards (2014–2026)
RETC PV Module Index2023, 2024, 2025, 2026
Current panel series in CEC list22

Other series by SoCal permits

JAM54D41-xxx/MB · 17JAM72D30-xxx/MB · 3JAM54S30-xxx/MR · 1JAM66D45-xxx/LBJAM54D30-xxx/MBJAM72D40-xxx/MB

Questions & answers

How efficient is the JA Solar JAM54S31-395/MR?

Calculated from the panel area (1.9 m²): about 20.8% for the 395 W class. 395 W over 1.9 m² equals about 208 W per square meter.

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

PVWatts v8 with typical-year weather gives about 662 kWh per year per 395 W panel in Los Angeles and about 725 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.329 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 17% 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 3–15 panels per string (Voc at 2 °C = 39.2 V, Vmp at 74 °C cell = 25.2 V). Final design must follow the inverter manual and NEC 690.7.

Has this panel been reliability-tested?

JAM54S31-xxx/MR was a PVEL Top Performer in 2023, 2024 (HSS, LID+LETID, TC).

Who installs it in Southern California?

Building permits name this series 152 times (Aug 2021 – Jan 2026). The most active licensed installers are Bright Ops, Sunrun, Homelink Solar.

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 2014–2026.
RETC — PV Module Index reports 2023–2026.
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 — Los Angeles County Public Works (EPIC-LA, unincorporated areas) (Aug 2021 – Dec 2025); City of Palmdale (Dec 2023 – Jan 2026); City of Huntington Beach (Aug 2024 – Jun 2025). Equipment matched from permit descriptions by model number.
Contractors State License Board — License Master (contractor names and license status), as of Oct 5, 2026.
Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).