Illustration · 268 cells

Solar panelFirst Solar

First Solar FS-6450A-P-B

Name: First Solar FS-6450A-P-B
Brand: First Solar

268 cells. Power classes 420–480 W in the CEC list.

CEC listed · Oct 2, 2023UL 61730

Power class

Power (STC)450 WCEC nameplate
Efficiency≈17.9%calculated from area
%/°C Pmax−0.296CEC listing test
PTC / STC92.6%PTC 416 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 13 models

Model	Pmax	Voc, V	Isc, A	Vmp, V	Imp, A	Efficiency	PTC	CEC listed
FS-6420A-P-B	420 W	218.50	2.54	180.40	2.33	≈16.7%	388 W	Jun 11, 2025
FS-6425A-P-B	425 W	218.90	2.54	181.50	2.34	≈16.9%	393 W	Jun 11, 2025
FS-6430A-P-B	430 W	219.20	2.54	182.60	2.36	≈17.1%	398 W	Jun 11, 2025
FS-6435A-P-B	435 W	219.60	2.55	183.60	2.37	≈17.3%	402 W	Jun 11, 2025
FS-6440A-P-B	440 W	220.00	2.55	184.70	2.38	≈17.5%	407 W	Oct 2, 2023
FS-6445A-P-B	445 W	220.40	2.56	185.70	2.40	≈17.7%	412 W	Oct 2, 2023
FS-6450A-P-B	450 W	221.10	2.57	186.80	2.41	≈17.9%	416 W	Oct 2, 2023
FS-6455A-P-B	455 W	222.00	2.58	187.80	2.42	≈18.1%	421 W	Oct 2, 2023
FS-6460A-P-B	460 W	222.90	2.59	188.80	2.44	≈18.3%	426 W	Oct 2, 2023
FS-6465A-P-B	465 W	223.80	2.60	189.80	2.45	≈18.5%	431 W	Oct 2, 2023
FS-6470A-P-B	470 W	224.30	2.61	191.10	2.46	≈18.7%	435 W	Oct 2, 2023
FS-6475A-P-B	475 W	224.80	2.61	191.50	2.48	≈18.8%	440 W	Oct 2, 2023
FS-6480A-P-B	480 W	225.40	2.62	192.80	2.49	≈19.0%	445 W	Oct 2, 2023

≈ efficiency = Pmax ÷ CEC-listed area 2.52 m².

Heat & cold behaviour

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

	CEC listing test
Pmax coefficient γ	−0.296 %/°C
Voc coefficient β	−0.271 %/°C
Isc coefficient α	+0.051 %/°C
Operating cell temperature	NOCT 50.1 °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
420 W	316.4 W	166.65 V × 1.9 A	82.4 W	98%
425 W	319.7 W	167.67 V × 1.91 A	83.3 W	98%
430 W	324.3 W	168.68 V × 1.92 A	84.5 W	98%
435 W	327.5 W	169.61 V × 1.93 A	85.3 W	98%
440 W	330.9 W	170.62 V × 1.94 A	86.2 W	98%
445 W	335.4 W	171.55 V × 1.96 A	87.4 W	98%
450 W	338.8 W	172.56 V × 1.96 A	88.3 W	98%
455 W	342.1 W	173.49 V × 1.97 A	89.1 W	98%
460 W	346.7 W	174.41 V × 1.99 A	90.3 W	98%
465 W	350 W	175.33 V × 2 A	91.2 W	98%
470 W	353.8 W	176.53 V × 2 A	92.2 W	98%
475 W	357.5 W	176.9 V × 2.02 A	93.1 W	98%
480 W	361.3 W	178.11 V × 2.03 A	94.1 W	98%

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

2023

PVEL Top Performer

closely related product name

Tests passed as Top Performer

DH, LID+LETID, MSS, PID, TC

PVEL Scorecards

First Solar named Top Performer, 2018–2023

PVEL Top Performer tests

Year	Product	Tests
2023	FS-6xxxA-P (closely related product name)	DHLID+LETIDMSSPIDTC

Tested bill of materials

PVEL-tested factoryUSA,Vietnam
Cell technology (tested BOM)CdTe
Module design (tested BOM)monofacial - glass//glass
Power class range tested430-475W

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

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

234.9 V

Voc when cold

per panel

155 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	1–2
Solis (Ginlong) S6-EH1P10K-H-US	600 V	80–520 V	datasheet	1–2
Solis (Ginlong) Solis-1P7.6K-4G-US	600 V	100–500 V	datasheet	1–2
Qcells Q.VOLT H7.6SX	498 V	234–498 V	CEC test window	2–2

Microinverters (one per panel)

Microinverter	Recommended module power	Max DC input	MPPT	Voc cold / Vmp hot	Check	DC/AC
Enphase IQ8X-80-M-US	320–540 W	79.5 V	43–60 V	234.9 / 155 V	✗ Not allowed: cold Voc above max input	1.18
APsystems (Alt Power System) DS3-L	265–570 W	60 V	28–45 V	234.9 / 155 V	✗ Not allowed: cold Voc above max input	0.58
Enphase IQ8M-72-2-US	260–460 W	60 V	30–45 V	234.9 / 155 V	✗ Not allowed: cold Voc above max input	1.38
Enphase IQ8A-72-2-US	295–500 W	60 V	32–45 V	234.9 / 155 V	✗ Not allowed: cold Voc above max input	1.29

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	754	12,067	6.08
Palmdale	1,835	826	13,212	6.69
Chula Vista	1,696	763	12,211	6.11
Huntington Beach	1,643	739	11,830	5.89
Riverside	1,696	763	12,211	6.21
Santa Clarita	1,724	776	12,413	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.

About First Solar

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

ManufacturerFirst Solar
Listed in CEC asFirst Solar, Inc.
Websitefirstsolar.com
PVEL Top Performer (manufacturer)5 Scorecards (2018–2023)
Current panel series in CEC list14

Other series by SoCal permits

FS-6xxx-P-BFS-6xxx-P-B-2FS-6xxxA-P-B-2FS-7xxxA-FT1FS-7xxxA-TR1FS-6xxxA-P

Questions & answers

How efficient is the First Solar FS-6450A-P-B?

Calculated from the panel area (2.52 m²): about 17.9% for the 450 W class. 450 W over 2.52 m² equals about 179 W per square meter.

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

PVWatts v8 with typical-year weather gives about 754 kWh per year per 450 W panel in Los Angeles and about 826 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.296 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 15.3% 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 1–2 panels per string (Voc at 2 °C = 234.9 V, Vmp at 74 °C cell = 155 V). Final design must follow the inverter manual and NEC 690.7.

Has this panel been reliability-tested?

FS-6xxxA-P was a PVEL Top Performer in 2023 (DH, LID+LETID, MSS, PID, TC) — a closely related product name.

Sources

California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists 2018–2023.
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).
Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).