Illustration · 156 half-cut cells

Solar panelJA Solar

JA Solar JAM78D10-440/MB

Name: JA Solar JAM78D10-440/MB
Brand: JA Solar

156 half-cut cells, bifacial. Power classes 435–445 W in the CEC list.

CEC listed · Jan 11, 2022UL 61730Bifacial

Power class

Power (STC)440 WCEC nameplate
Efficiency≈20.5%calculated from area
%/°C Pmax−0.329CEC listing test
PTC / STC93.6%PTC 412 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 3 models

Model	Pmax	Voc, V	Isc, A	Vmp, V	Imp, A	Efficiency	PTC	CEC listed
JAM78D10-435/MB	435 W	52.74	10.32	44.31	9.82	≈20.2%	407 W	Jan 11, 2022
JAM78D10-440/MB	440 W	53.01	10.37	44.68	9.85	≈20.5%	412 W	Jan 11, 2022
JAM78D10-445/MB	445 W	53.29	10.42	44.96	9.90	≈20.7%	417 W	Jan 11, 2022

≈ efficiency = Pmax ÷ CEC-listed area 2.15 m².

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	−0.263 %/°C
Isc coefficient α	+0.038 %/°C
Operating cell temperature	NOCT 45.4 °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
435 W	323.9 W	41.33 V × 7.84 A	82.5 W	95%
440 W	327.6 W	41.68 V × 7.86 A	83.4 W	95%
445 W	331.3 W	41.94 V × 7.9 A	84.4 W	95%

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

PVEL Scorecards

JA Solar named Top Performer, 2014–2026

2023, 2024, 2025, 2026

RETC Overall Highest Achiever

JA Solar, manufacturer level

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

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

56.2 V

Voc when cold

per panel

36.6 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	3–10
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	7–8

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	56.2 / 36.6 V	✓ Within range	1.52
Enphase IQ8X-80-M-US	320–540 W	79.5 V	43–60 V	56.2 / 36.6 V	⚠ Works; below MPPT at peak heat	1.16
APsystems (Alt Power System) DS3-L	265–570 W	60 V	28–45 V	56.2 / 36.6 V	✓ Within range	0.56
Enphase IQ8M-72-2-US	260–460 W	60 V	30–45 V	56.2 / 36.6 V	✓ Within range	1.35
Enphase IQ8A-72-2-US	295–500 W	60 V	32–45 V	56.2 / 36.6 V	✓ Within range	1.26

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	737	11,799	6.08
Palmdale	1,835	807	12,918	6.69
Chula Vista	1,696	746	11,940	6.11
Huntington Beach	1,643	723	11,567	5.89
Riverside	1,696	746	11,940	6.21
Santa Clarita	1,724	759	12,137	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 440 W panels

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

Panel	Pmax	Efficiency	γ Pmax (CEC)	Voc, V	Isc, A	Warranty	PVEL (product / brand)	SoCal permits (series)
JA Solar JAM78D10-440/MB	440 W	≈20.5%	−0.329	53.01	10.37	—	brand 11×	—
Qcells Q.TRON BLK M-G2+ 440	440 W	≥22.5%	−0.276	39.88	13.9	25 / 25 yr	brand 11× (2016–2026)	40
Silfab Solar SIL-440QD	440 W	≈22.6%	−0.294	38.97	14.25	25 / 30 yr	brand 7× (2017–2025)	39
Hyundai Energy Solutions HiN-T440NF(BK)	440 W	≈22.7%	−0.298	38.8	14.39	25 / 30 yr	brand 5× (2017–2025)	37

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

JAM54S31-xxx/MR · 152JAM54D41-xxx/MB · 17JAM72D30-xxx/MB · 3JAM54S30-xxx/MR · 1JAM66D45-xxx/LBJAM54D30-xxx/MB

Questions & answers

How efficient is the JA Solar JAM78D10-440/MB?

Calculated from the panel area (2.15 m²): about 20.5% for the 440 W class. 440 W over 2.15 m² equals about 205 W per square meter.

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

PVWatts v8 with typical-year weather gives about 737 kWh per year per 440 W panel in Los Angeles and about 807 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 2–10 panels per string (Voc at 2 °C = 56.2 V, Vmp at 74 °C cell = 36.6 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 56.2 V vs max input 60 V; Vmp when hot 36.6 V vs MPPT low 29 V; recommended module power 235–440 W. Confirm on the microinverter maker’s compatibility list.

Is it bifacial?

Yes. Rear gain depends on mounting height and ground reflectance.

Has this panel been reliability-tested?

This exact series is not in published PVEL Top Performer tables; JA Solar was named a Top Performer in 11 Scorecards (2014–2026). RETC named JA Solar Overall Highest Achiever in 2023, 2024, 2025, 2026.

Sources

California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
Qcells — manufacturer datasheet “Q.TRON BLK M-G2+ SERIES 415–440 Wp”.
Silfab Solar — datasheet NTC SIL-420 QD CELL TECHNOLOGY.
Hyundai Energy Solutions — datasheet [US] NF(BK)(HiN) Series (N TOPCon Bifacial) 435~445W.
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 module and inverter libraries (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).