Illustration · 144 half-cut cells

Solar panelURE (United Renewable Energy)

URE (United Renewable Energy) D2K405P8A

Name: URE (United Renewable Energy) D2K405P8A
Brand: URE (United Renewable Energy)

144 half-cut cells, bifacial. Power classes 390–420 W in the CEC list.

CEC listed · Jun 1, 2020UL 61730Bifacial

Power class

Power (STC)405 WCEC nameplate
Efficiency≈20.0%calculated from area
%/°C Pmax−0.390CEC listing test
PTC / STC92.2%PTC 374 W (CEC)

Power classes

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

Model	Pmax	Voc, V	Isc, A	Vmp, V	Imp, A	Efficiency	PTC	CEC listed
D2K390P8A	390 W	48.43	10.36	40.04	9.74	≈19.2%	359 W	Jun 1, 2020
D2K395P8A	395 W	48.44	10.45	40.12	9.85	≈19.5%	364 W	Jun 1, 2020
D2K400P8A	400 W	48.46	10.55	40.20	9.95	≈19.7%	369 W	Jun 1, 2020
D2K405P8A	405 W	48.47	10.67	40.28	10.05	≈20.0%	374 W	Jun 1, 2020
D2K410P8A	410 W	48.49	10.75	40.36	10.16	≈20.2%	378 W	Jun 1, 2020
D2K415P8A	415 W	48.51	10.85	40.44	10.26	≈20.4%	383 W	Jun 1, 2020
D2K420P8A	420 W	48.52	10.95	40.52	10.37	≈20.7%	388 W	Jun 1, 2020

≈ efficiency = Pmax ÷ CEC-listed area 2.03 m².

Heat & cold behaviour

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

	CEC listing test
Pmax coefficient γ	−0.390 %/°C
Voc coefficient β	−0.307 %/°C
Isc coefficient α	+0.060 %/°C
Operating cell temperature	NOCT 45.6 °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
390 W	288.6 W	36.14 V × 7.99 A	74.6 W	96%
395 W	292.5 W	36.21 V × 8.08 A	75.6 W	96%
400 W	296 W	36.28 V × 8.16 A	76.5 W	96%
405 W	299.6 W	36.35 V × 8.24 A	77.5 W	96%
410 W	303.5 W	36.42 V × 8.33 A	78.5 W	96%
415 W	307.1 W	36.5 V × 8.41 A	79.4 W	96%
420 W	311 W	36.57 V × 8.5 A	80.4 W	96%

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

51.9 V

Voc when cold

per panel

31.4 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. 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	51.9 / 31.4 V	✓ Within range	1.4
Enphase IQ8X-80-M-US	320–540 W	79.5 V	43–60 V	51.9 / 31.4 V	✗ Not a match: module voltage below MPPT range	1.07
APsystems (Alt Power System) DS3-L	265–570 W	60 V	28–45 V	51.9 / 31.4 V	✓ Within range	0.52
Enphase IQ8M-72-2-US	260–460 W	60 V	30–45 V	51.9 / 31.4 V	✓ Within range	1.25
Enphase IQ8A-72-2-US	295–500 W	60 V	32–45 V	51.9 / 31.4 V	⚠ Works; below MPPT at peak heat	1.16

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	679	11,539	6.08
Palmdale	1,835	743	12,634	6.69
Chula Vista	1,696	687	11,677	6.11
Huntington Beach	1,643	665	11,312	5.89
Riverside	1,696	687	11,677	6.21
Santa Clarita	1,724	698	11,870	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 405 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)
URE (United Renewable Energy) D2K405P8A	405 W	≈20%	−0.390	48.47	10.67	—	—
Qcells Q.PEAK DUO BLK ML-G10+ 405	405 W	≥20.6%	−0.362	45.34	11.17	product 2022, 2023	221
JA Solar JAM54S31-405/MR	405 W	≈21.3%	−0.329	37.23	13.87	product 2023, 2024	152
REC Group REC405AA Pure	405 W	≈22.6%	−0.256	48.9	10.3	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.

Questions & answers

How efficient is the URE (United Renewable Energy) D2K405P8A?

Calculated from the panel area (2.03 m²): about 20% for the 405 W class. 405 W over 2.03 m² equals about 200 W per square meter.

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

PVWatts v8 with typical-year weather gives about 679 kWh per year per 405 W panel in Los Angeles and about 743 kWh in Palmdale (20° roof, facing south, 14% system losses).

How much power does it lose on a hot roof?

With γ = −0.390 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 20.2% 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 = 51.9 V, Vmp at 74 °C cell = 31.4 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 51.9 V vs max input 60 V; Vmp when hot 31.4 V vs MPPT low 29 V; recommended module power 235–440 W. Confirm on the microinverter maker’s compatibility list.

Is it bifacial?

Yes. Rear gain depends on mounting height and ground reflectance.

Sources

California Energy Commission — Solar Equipment Lists, PV Module List, Inverter List (snapshot Oct 7, 2026).
Qcells — manufacturer datasheet “Q.PEAK DUO BLK ML-G10+ ENDURING HIGH PERFORMANCE”.
Kiwa PVEL — PV Module Reliability Scorecard, Top Performer lists.
NLR (formerly NREL) — System Advisor Model CEC module and inverter libraries (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).