Jackery JS-42A

Name: Jackery JS-42A
Brand: Jackery

16 cells. Power classes 36–45 W in the CEC list.

CEC listed · Jun 23, 2025UL 61730Building-integrated (BIPV)

Power class

Power (STC)42 WCEC nameplate
Efficiency≈14.3%calculated from area
%/°C Pmax−0.379CEC listing test
PTC / STC92.4%PTC 39 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 4 models

Model	Pmax	Voc, V	Isc, A	Vmp, V	Imp, A	Efficiency	PTC	CEC listed
JS-36A	36 W	5.54	8.85	4.53	7.95	≈12.3%	33 W	Jun 23, 2025
JS-38A	38 W	5.54	9.14	4.53	8.38	≈13.0%	35 W	Jun 23, 2025
JS-42A	42 W	5.54	10.32	4.53	9.56	≈14.3%	39 W	Jun 23, 2025
JS-45A	45 W	5.54	10.36	4.53	9.93	≈15.4%	42 W	Jun 23, 2025

≈ efficiency = Pmax ÷ CEC-listed area 0.29 m².

Build & dimensions

CEC PV Module List (Oct 7, 2026)

Module area0.29 m² (3.2 ft²)CEC-listed area
Cells16 cells
FrameBlack frame

Heat & cold behaviour

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

	CEC listing test
Pmax coefficient γ	−0.379 %/°C
Voc coefficient β	−0.260 %/°C
Isc coefficient α	+0.037 %/°C
Operating cell temperature	NOCT 44.1 °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
36 W	36 W	4.37 V × 8.24 A	—	—
38 W	37.9 W	4.37 V × 8.69 A	—	—
42 W	38.8 W	4.32 V × 8.99 A	—	—
45 W	40.3 W	4.32 V × 9.34 A	—	—

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

CityColdest air, °CHottest cell, °C

5.9 V

Voc when cold

per panel

3.6 V

Vmp when hot

per panel

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.

Integrated roof products are wired per the manufacturer’s system design.

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	70	11,755	6.08
Palmdale	1,835	77	12,871	6.69
Chula Vista	1,696	71	11,896	6.11
Huntington Beach	1,643	69	11,524	5.89
Riverside	1,696	71	11,896	6.21
Santa Clarita	1,724	72	12,092	6.28

PVWatts models a standard roof-mounted module; integrated roof products are not modeled separately.

Estimate for comparison, not a quote: shading, roof orientation and local losses change real output. Roof mount, 20° tilt, south, 14% system losses.

Questions & answers

How efficient is the Jackery JS-42A?

Calculated from the panel area (0.29 m²): about 14.3% for the 42 W class. 42 W over 0.29 m² equals about 143 W per square meter.

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

PVWatts v8 with typical-year weather gives about 70 kWh per year per 42 W panel in Los Angeles and about 77 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.379 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 19.6% below the STC rating.

Sources

California Energy Commission — Solar Equipment Lists, PV Module List (snapshot Oct 7, 2026).
NLR (formerly NREL) — PVWatts v8, NSRDB PSM v3 typical-year weather for Los Angeles, Palmdale, Chula Vista, Huntington Beach, Riverside, Santa Clarita.
Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).