39.2″ · 996 mm wide · 1.38″ (35 mm) frame · 52.9 lb (24 kg)

Solar panelCanadian Solar

Canadian Solar CS1Y-390MS

Name: Canadian Solar CS1Y-390MS
Brand: Canadian Solar

Power classes 380–415 W in the CEC list; datasheet covers 390–405 W.

CEC listed · Jan 11, 2021UL 61730PERCInstalled in 6 SoCal permits

Power class

Power (STC)390 Wtolerance +10 / −0 W
Efficiency≥19.4%datasheet minimum
%/°C Pmax−0.36CEC test: −0.347
PTC / STC94%PTC 367 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · Canadian Solar datasheet · 8 models

Model	Pmax	Voc, V	Isc, A	Vmp, V	Imp, A	Efficiency	PTC	CEC listed
CS1Y-380MS	380 W	51.50	9.74	42.70	8.89	≈18.9%	357 W	Jan 11, 2021
CS1Y-385MS	385 W	51.70	9.78	42.90	8.97	≈19.1%	362 W	Jan 11, 2021
CS1Y-390MS	390 W	51.90	9.82	43.10	9.05	≥19.4%	367 W	Jan 11, 2021
CS1Y-395MS	395 W	52.10	9.86	43.30	9.13	≥19.6%	372 W	Jan 11, 2021
CS1Y-400MS	400 W	52.30	9.90	43.50	9.20	≥19.9%	376 W	Jan 11, 2021
CS1Y-405MS	405 W	52.50	9.94	43.70	9.27	≥20.1%	381 W	Jan 11, 2021
CS1Y-410MS	410 W	52.70	9.98	43.80	9.37	≈20.4%	386 W	Jan 11, 2021
CS1Y-415MS	415 W	52.80	10.02	44.00	9.44	≈20.6%	391 W	Jan 11, 2021

≈ efficiency = Pmax ÷ panel area 2.013 m² (datasheet size) for classes outside the datasheet.

CEC note: Formerly listed under Canadian Solar Inc.

Build & dimensions

Canadian Solar datasheet · Cali-Graf calculation

Dimensions79.6 × 39.2 × 1.38 in2,021 × 996 × 35 mm
Module area2.01 m² (21.7 ft²)length × width
Weight52.9 lb (24 kg)
Front glass3.2 mm tempered glass
Junction boxIP68, 3 bypass diodes
Cable / connector4.0 mm² (IEC), 12 AWG (UL) · T4 series or MC4

Heat & cold behaviour

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

	Datasheet	CEC listing test
Pmax coefficient γ	−0.36 %/°C	−0.347 %/°C
Voc coefficient β	−0.28 %/°C	−0.273 %/°C
Isc coefficient α	+0.05 %/°C	+0.043 %/°C
Vmp coefficient	≈ −0.41 %/°C	—
Operating cell temperature	NMOT 43 ± 3 °C	NOCT 42.9 °C

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

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

Class	Pmax, W	Voc, V	Isc, A	Vmp, V	Imp, A
390 W	289.0	48.60	7.92	39.90	7.25
395 W	293.0	48.80	7.96	40.10	7.31
400 W	297.0	49.00	7.99	40.30	7.37
405 W	300.0	49.20	8.02	40.40	7.43

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
380 W	286.1 W	40.01 V × 7.15 A	72.3 W	95%
385 W	290 W	40.2 V × 7.21 A	73.3 W	95%
390 W	293.9 W	40.39 V × 7.28 A	74.3 W	95%
395 W	297.9 W	40.58 V × 7.34 A	75.3 W	95%
400 W	301.6 W	40.76 V × 7.4 A	76.2 W	95%
405 W	305.3 W	40.95 V × 7.45 A	77.1 W	95%
410 W	309.3 W	41.05 V × 7.53 A	78.1 W	95%
415 W	313 W	41.23 V × 7.59 A	79.1 W	95%

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 fuse16 A
Module temperature−40 °F to +185 °F−40 °C to +85 °C
Power tolerance+10 / −0 W

Certifications

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

UL 61730IEC 61215IEC 61730IEC 61701IEC 62716ISO 14001ISO 45001ISO 9001

UL 61730CEC listing
IEC 61215datasheet
IEC 61730datasheet
IEC 61701datasheet
IEC 62716datasheet
ISO 14001factory, datasheet
ISO 45001factory, datasheet
ISO 9001factory, datasheet

Independent reliability testing

Kiwa PVEL Scorecard · RETC PV Module Index

PVEL Scorecards

Canadian Solar named Top Performer, 2020–2026

RETC PV Module Index

Canadian Solar, 2025

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

RETC PV Module Index — Canadian Solar

Year	Recognition
2025	Reliability High Achiever

Inverter compatibility & string sizing

Canadian Solar 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

55.2 V

Voc when cold

per panel

34.4 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	2–10
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	7–9

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	55.2 / 34.4 V	✓ Within range	1.34
Enphase IQ8X-80-M-US	320–540 W	79.5 V	43–60 V	55.2 / 34.4 V	⚠ Works; below MPPT at peak heat	1.03
APsystems (Alt Power System) DS3-L	265–570 W	60 V	28–45 V	55.2 / 34.4 V	✓ Within range	0.5
Enphase IQ8M-72-2-US	260–460 W	60 V	30–45 V	55.2 / 34.4 V	✓ Within range	1.2
Enphase IQ8A-72-2-US	295–500 W	60 V	32–45 V	55.2 / 34.4 V	✓ Within range	1.12

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	654	11,766	6.08
Palmdale	1,835	716	12,882	6.69
Chula Vista	1,696	661	11,906	6.11
Huntington Beach	1,643	641	11,534	5.89
Riverside	1,696	661	11,906	6.21
Santa Clarita	1,724	672	12,102	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 CS1Y-xxxMS panels in SoCal

building permits

Permits naming this series

Oct 2021 – Jan 2025

Jurisdictions so far

LA County (unincorp.) (6)

Permits over time

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

Inverters

Sol-Ark (model not specified)

SolarEdge SE…H (HD-Wave)

Batteries

Humless (model not specified)

Number of permits naming both this panel series and the product; 6 of 6 permits list other equipment.

Compare with similar 390 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)
Canadian Solar CS1Y-390MS	390 W	≥19.4%	−0.347	51.9	9.82	brand 5×	6
Qcells Q.PEAK DUO BLK ML-G10+ 390	390 W	≥19.9%	−0.362	45.23	11.07	product 2022, 2023	221
JA Solar JAM54S31-390/MR	390 W	≈20.5%	−0.329	36.85	13.61	product 2023, 2024	152
REC Group REC390AA Pure	390 W	≈21.8%	−0.256	48.6	10.19	brand 9× (2016–2025)	66

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 Canadian Solar

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

ManufacturerCanadian Solar
Listed in CEC asCSI Energy Storage Co., Ltd., CSI Solar Co., Ltd., Canadian Solar
Websitecanadiansolar.com
PVEL Top Performer (manufacturer)5 Scorecards (2020–2026)
RETC PV Module Index2025
Current panel series in CEC list38

Other series by SoCal permits

CS6R-xxxMS-HL · 46CS3N-xxxMS · 46CS6.1-54TM-xxxH · 9CS3W-xxxMS · 6CS3W-xxxMB-AG · 5CS7N-xxxMB-AG · 2

Questions & answers

How efficient is the Canadian Solar CS1Y-390MS?

The Canadian Solar datasheet guarantees at least 19.4% module efficiency for the 390 W class (up to 20.1% for 405 W). 390 W over 2.01 m² equals about 194 W per square meter.

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

PVWatts v8 with typical-year weather gives about 654 kWh per year per 390 W panel in Los Angeles and about 716 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.36 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 18.6% 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 = 55.2 V, Vmp at 74 °C cell = 34.4 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 55.2 V vs max input 60 V; Vmp when hot 34.4 V vs MPPT low 29 V; recommended module power 235–440 W. Confirm on the microinverter maker’s compatibility list.

How big and heavy is it?

79.6 × 39.2 × 1.38 in (2,021 × 996 × 35 mm), 52.9 lb (24 kg).

Has this panel been reliability-tested?

This exact series is not in published PVEL Top Performer tables; Canadian Solar was named a Top Performer in 5 Scorecards (2020–2026).

Sources

California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
Canadian Solar — manufacturer datasheet “HiDM5 (All-Black) ALL-BLACK HIGH DENSITY MONO PERC MODULE”.
Qcells — manufacturer datasheet “Q.PEAK DUO BLK ML-G10+ ENDURING HIGH PERFORMANCE”.
Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists 2020–2026.
RETC — PV Module Index report.
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 – Jan 2025). 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).