Illustration · 144 half-cut cells

Solar panelFreeVolt

FreeVolt ECP-PVGRAF-144BHC 440

Name: FreeVolt ECP-PVGRAF-144BHC 440
Brand: FreeVolt

144 half-cut cells. Power classes 430–450 W in the CEC list.

CEC listed · Aug 1, 2022UL 61730

Power class

Power (STC)440 WCEC nameplate
Efficiency≈20.6%calculated from area
%/°C Pmax−0.381CEC listing test
PTC / STC92.6%PTC 407 W (CEC)

Power classes

CEC PV Module List (Oct 7, 2026) · Cali-Graf calculation · 5 models

Model	Pmax	Voc, V	Isc, A	Vmp, V	Imp, A	Efficiency	PTC	CEC listed
ECP-PVGRAF-144BHC-430W	430 W	48.90	11.30	40.60	10.60	≈20.1%	398 W	Aug 1, 2022
ECP-PVGRAF-144BHC-435W	435 W	49.10	11.36	40.80	10.67	≈20.3%	403 W	Aug 1, 2022
ECP-PVGRAF-144BHC-440W	440 W	49.30	11.45	41.00	10.74	≈20.6%	407 W	Aug 1, 2022
ECP-PVGRAF-144BHC-445W	445 W	49.50	11.52	41.20	10.81	≈20.8%	412 W	Aug 1, 2022
ECP-PVGRAF-144BHC-450W	450 W	49.60	11.58	41.40	10.87	≈21.0%	417 W	Aug 1, 2022

≈ efficiency = Pmax ÷ CEC-listed area 2.14 m².

Heat & cold behaviour

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

	CEC listing test
Pmax coefficient γ	−0.381 %/°C
Voc coefficient β	−0.312 %/°C
Isc coefficient α	+0.062 %/°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
430 W	323.2 W	37.94 V × 8.52 A	83.6 W	97%
435 W	326.9 W	38.13 V × 8.57 A	84.6 W	97%
440 W	330.7 W	38.32 V × 8.63 A	85.6 W	97%
445 W	334.5 W	38.5 V × 8.69 A	86.5 W	97%
450 W	338 W	38.69 V × 8.73 A	87.4 W	97%

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 · inverter datasheets · NLR SAM inverter library · CEC Grid Support Inverter List (Oct 7, 2026)

CityColdest air, °CHottest cell, °CString inverter

52.8 V

Voc when cold

per panel

32.1 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	2–11
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	4–11
Qcells Q.VOLT H7.6SX	498 V	234–498 V	CEC test window	8–9

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	52.8 / 32.1 V	✓ Within range	1.52
Enphase IQ8X-80-M-US	320–540 W	79.5 V	43–60 V	52.8 / 32.1 V	✗ Not a match: module voltage below MPPT range	1.16
APsystems (Alt Power System) DS3-L	265–570 W	60 V	28–45 V	52.8 / 32.1 V	✓ Within range	0.56
Enphase IQ8M-72-2-US	260–460 W	60 V	30–45 V	52.8 / 32.1 V	✓ Within range	1.35
Enphase IQ8A-72-2-US	295–500 W	60 V	32–45 V	52.8 / 32.1 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)
FreeVolt ECP-PVGRAF-144BHC 440	440 W	≈20.6%	−0.381	49.3	11.45	—	—	—
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.

Questions & answers

How efficient is the FreeVolt ECP-PVGRAF-144BHC 440?

Calculated from the panel area (2.14 m²): about 20.6% for the 440 W class. 440 W over 2.14 m² equals about 206 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 = −0.381 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 19.7% 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 = 52.8 V, Vmp at 74 °C cell = 32.1 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 52.8 V vs max input 60 V; Vmp when hot 32.1 V vs MPPT low 29 V; recommended module power 235–440 W. Confirm on the microinverter maker’s compatibility list.

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.
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 — 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).