Illustration · 144 half-cut cells

Solar panelTesla

Tesla T425S

Name: Tesla T425S
Brand: Tesla

144 half-cut cells. Power classes 420–430 W in the CEC list.

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

Power class

Power (STC)425 Wtolerance +5 / −0 W
Efficiency≥19.6%datasheet minimum
%/°C Pmax−0.33CEC test: −0.331
Degradation / yr0.54%after year 1 (warranty)

Power classes

CEC PV Module List (Oct 7, 2026) · Tesla datasheet · 3 models

Model	Pmax	Voc, V	Isc, A	Vmp, V	Imp, A	Efficiency	PTC	CEC listed
T420S	420 W	48.50	11.16	40.90	10.27	≥19.3%	392 W	Jul 1, 2021
T425S	425 W	48.65	11.24	41.05	10.36	≥19.6%	397 W	Jul 1, 2021
T430S	430 W	48.80	11.32	41.20	10.44	≥19.8%	402 W	Jul 1, 2021

Build & dimensions

CEC PV Module List (Oct 7, 2026) · Tesla datasheet

Module area2.11 m² (22.7 ft²)CEC-listed area
Weight55.8 lb (25.3 kg)
Cells144 half-cut cells
Front glass3.2 mm ARC Glass
Back coverBlack backsheet
FrameBlack Anodized Aluminum Alloy
Junction boxIP68, 3 diodes
Cable / connector4 mm2 | 12 AWG, 1400 mm | 55.1 in. Length · Staubli MC4 or EVO2

Heat & cold behaviour

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

	Datasheet	CEC listing test
Pmax coefficient γ	−0.33 %/°C	−0.331 %/°C
Voc coefficient β	−0.26 %/°C	−0.260 %/°C
Isc coefficient α	+0.04 %/°C	+0.040 %/°C
Vmp coefficient	≈ −0.37 %/°C	—
Operating cell temperature	NMOT 45.7 °C	NOCT 45.6 °C

Vmp coefficient ≈ γ − α (datasheet); used only for the hot-roof voltage estimate.

At normal operating conditions (NOCT, 800 W/m²) — datasheet

Class	Pmax, W	Voc, V	Isc, A	Vmp, V	Imp, A
420 W	313.7	45.47	9.02	38.08	8.24
425 W	317.4	45.61	9.09	38.22	8.30
430 W	321.1	45.75	9.15	38.36	8.37

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
420 W	314.4 W	38.12 V × 8.25 A	81.7 W	97%
425 W	318.3 W	38.26 V × 8.32 A	82.7 W	97%
430 W	322 W	38.4 V × 8.38 A	83.7 W	97%

Pmax = Vmp × Imp from the CEC listing; low-light efficiency = Pmax at 200 W/m² ÷ (20% of STC Pmax).

Electrical & strength ratings

Max system voltage1,000 V
Max series fuse20 A
Fire rating (UL 61730)Type 1
Module temperature−40 °F to +185 °F−40 °C to +85 °C
Hail25 mm (0.98 in) at 23 km/h
Power tolerance+5 / −0 W

Certifications

CEC PV Module List (Oct 7, 2026) · Tesla datasheet

UL 61730Fire rating Type 1 (UL 61730)

UL 61730CEC listing
Fire rating Type 1 (UL 61730)datasheet

Warranty & degradation

Tesla datasheet

Then≤ 0.54% / year

Inverter compatibility & string sizing

Tesla datasheet · Cali-Graf calculation · NLR PVWatts v8 · CEC PV Module List (Oct 7, 2026) · inverter datasheets · NLR SAM inverter library · CEC Grid Support Inverter List (Oct 7, 2026)

CityColdest air, °CHottest cell, °CString inverter

51.6 V

Voc when cold

per panel

33.6 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.

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	51.6 / 33.6 V	✓ Within range	1.47
Enphase IQ8X-80-M-US	320–540 W	79.5 V	43–60 V	51.6 / 33.6 V	✗ Not a match: module voltage below MPPT range	1.12
APsystems (Alt Power System) DS3-L	265–570 W	60 V	28–45 V	51.6 / 33.6 V	✓ Within range	0.54
Enphase IQ8M-72-2-US	260–460 W	60 V	30–45 V	51.6 / 33.6 V	✓ Within range	1.31
Enphase IQ8A-72-2-US	295–500 W	60 V	32–45 V	51.6 / 33.6 V	✓ Within range	1.22

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	712	11,397	6.08
Palmdale	1,835	780	12,478	6.69
Chula Vista	1,696	721	11,533	6.11
Huntington Beach	1,643	698	11,172	5.89
Riverside	1,696	721	11,533	6.21
Santa Clarita	1,724	733	11,723	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 425 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)
Tesla T425S	425 W	≥19.6%	−0.331	48.65	11.24	—	—	1
Canadian Solar CS3N-425MS	425 W	≥20.9%	−0.332	45.5	11.8	25 yr	product 2023	46
Qcells Q.TRON BLK M-G2+ 425	425 W	≥21.8%	−0.276	39.03	13.66	25 / 25 yr	brand 11× (2016–2026)	40
Silfab Solar SIL-425QD	425 W	≈21.8%	−0.294	38.88	13.68	25 / 30 yr	brand 7× (2017–2025)	39

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 Tesla T425S?

The Tesla datasheet guarantees at least 19.6% module efficiency for the 425 W class (up to 19.8% for 430 W). 425 W over 2.11 m² equals about 201 W per square meter.

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

PVWatts v8 with typical-year weather gives about 712 kWh per year per 425 W panel in Los Angeles and about 780 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.33 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 17.1% 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 = 51.6 V, Vmp at 74 °C cell = 33.6 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 51.6 V vs max input 60 V; Vmp when hot 33.6 V vs MPPT low 29 V; recommended module power 235–440 W. Confirm on the microinverter maker’s compatibility list.

What fire rating does it have?

UL 61730 fire rating Type 1 per datasheet.

Sources

California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
Tesla — manufacturer datasheet “Tesla Photovoltaic Module T420S, T425S, and T430S”.
Canadian Solar — manufacturer datasheet “HiKu Mono PERC CS3N-400|405|410|415|420|425MS MORE POWER”.
Qcells — manufacturer datasheet “Q.TRON BLK M-G2+ SERIES 415–440 Wp”.
Silfab Solar — datasheet NTC SIL-420 QD CELL TECHNOLOGY.
Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists.
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) (Oct 2021). 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).