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REC REC420AA PURE 2
REC Brand review

REC420AA PURE 2

420 Wp HJT Bifacial
ComparePV verdict

Middle of its segment, short guarantee

Rank 9,479 of 14,129
Compare panels Datasheet PDF
Power (Wp)
420
Weak · bottom 23%
Efficiency (%)
21.60
Weak · bottom 19%
Density (Wp/m²)
216.5
Weak · bottom 21%
Temp (%/°C)
-0.240
Typical · median -0.240
Weight (kg)
21.7
Typical · median 23.0 kg
Warranty (yrs)
25
Weak · bottom 8%

The REC Alpha Pure 2 series is a breakthrough solution based on advanced heterojunction cells (HJT), which set new efficiency standards in the Polish micro-installation sector. Thanks to an innovative cell layout and the elimination of unnecessary gaps, these panels offer maximum power density, allowing for significantly more energy generation from limited roof space. It is one of the few options on the market distinguished by a completely lead-free construction, making it an eco-friendly choice that meets strict environmental standards. The applied Twin Design technology, which divides the module into two independent sections, effectively solves the problem of production drops in partial shading conditions, setting this series apart from standard competitor solutions. Exceptional durability is ensured by additional frame reinforcements, protecting components from extreme wind pressure or heavy snow loads. The product is dedicated to demanding homeowners and businesses that value unique Full Black aesthetics combined with the highest cell performance in high temperatures. Investing in this series is a guarantee of long-term energy stability and security, backed by one of the strongest warranty coverages in the photovoltaic industry.

Ranking

113 panels in the segment HJT 400-450 W
Metric This panel Median Position in segment Overall rank
Module efficiency 21.60% 22.20% Weak · bottom 19% 7,716
Power density 216.5 221.6 Weak · bottom 21% 7,655
Temperature coefficient -0.240 -0.240 Typical 13
Weight per kWp 51.7 52.4 Typical 5,052
Performance warranty 25 yrs 30 yrs Weak · bottom 8% 9,912
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Signals from the data

5 positive · 4 caution
Best for

Residential, commercial, shaded-installations and hot-climate.

Not ideal for

Owners who want a long output guarantee, tight roof space and roofs where every square metre has to count.

Watch-outs
25 year performance warranty

Bottom 8% of the HJT 400-450 W segment, against a median of 30 yrs. Ranked 9,912th in the whole database.

21.60% module efficiency

Bottom 19% of the HJT 400-450 W segment, against a median of 22.20%.

216.5 watts per square metre

Bottom 21% of the HJT 400-450 W segment, against a median of 221.6.

What owners get
Highest efficiency in peer segment

Efficiency up to 22.2% exceeds comparable series in this dataset: Silfab Elite (21.9%), EGing STAR Pro (22.02%), and Boviet GAMMA (19.8%). For the same roof area, the installation generates real more energy than competing tier-1 panels.

Lead-free HJT technology

Heterojunction (HJT) cells in a fully lead-free construction are rare in the microinstallation segment, meeting stringent RoHS environmental standards. A low temperature coefficient of -0.24%/°C means smaller power losses on hot days compared to PERC panels (typically -0.35% to -0.45%/°C).

25-year warranty with low degradation

The manufacturer guarantees at least 92% of nameplate power after 25 years of operation, with annual degradation of only 0.25%. This outperforms the standard power warranty of most tier-1 peers in this segment, where 25-year guaranteed output is typically around 84-87%.

Bifacial design boosting energy yield

The REC Alpha Pure 2's bifaciality factor reaches 70-90%, which, with proper mounting (e.g., on a light-colored surface), can increase total energy output by an additional 5-15% compared to monofacial panels.

Twin Design construction resists shading

Splitting the module into two independent electrical sections limits production drops under partial shading (e.g., leaves, chimney, antenna), setting the series apart from standard panels with a single cell string.

Trade-offs
Priced above mainstream panels

Installed cost for the Alpha Pure series is estimated at $3.10-3.55/W, roughly $0.30-0.50/W higher than mainstream panels. The HJT premium may not pay off in a budget-constrained typical prosumer installation despite the higher efficiency.

Notes from the database
  • At 21.6% efficiency, this panel is 0.6pp below the HJT 400-450W median of 22.2%
  • 216.5 W/m² power density is 5.1 W/m² below HJT 400-450W median (221.6 W/m²) - requires larger installation area
  • At -0.24%/°C, hot weather performance is typical for HJT 400-450W panels
  • Weight of 21.7 kg (1.3 kg below HJT 400-450W median of 23.0 kg) allows easier transport and roof mounting
  • #7716 for efficiency, #13 for temperature performance out of 14129 panels

Specifications

Open datasheet PDF
Nominal power (Pmax) 420 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 21.60 % Weak Segment median 22.20%
Vmpp · Impp 41.20 V · 10.20 A Operating point at max power
Voc · Isc 49.10 V · 10.83 A Sizes the string length
Max system voltage 1000 V Longer strings than 1000 V modules
Dimensions 1865×1040×30 mm · 1.94 m² of roof
Weight 21.7 kg Typical Typical · median 23.0 kg
Cells 132 · HJT Monocrystalline
Coefficient Pmax -0.240 %/°C Typical median -0.240 of its segment
Coefficient Voc · Isc -0.240 · 0.040 %/°C
NOCT 44 °C At 800 W/m², 20 °C ambient
Product warranty 25 years Hardware defects only
Performance warranty 25 years Weak bottom 8% · median 30 yrs
End-of-warranty output 92.0 % Equals 381 W guaranteed
Degradation 2.00 → 0.25 % First year, then annual

Datasheet charts

Open datasheet PDF

Measured curves published by REC in this model's datasheet. A chart carrying a wattage was measured on that variant alone - only the ones that describe 420 Wp appear here. The rest cover the whole series.

Relative Efficiency vs. Irradiance Relative Efficiency vs. Irradiance Whole series

Simulations

Live - change any input
Lifetime output & value
30 years at 1200 kWh/kWp/year and €0.50 per kWh
Power in year 30
-
Lifetime energy
-
Energy value
-

Degradation from this panel's own datasheet figures. No inverter, soiling or shading losses.

Heat losses
-0.240 %/°C against a segment median of -0.240
-
Filter these
Size
Panel Power Eff. Temp. Weight Difference
REC REC420AA PURE 2 420 W 21.60% -0.240 21.7 kg You are here
JST-EDMH-(445-465)W-TD (465W class) 465 W 23.81% -0.300 20.5 kg Hotter, +2.2 pp, +5 yr warranty
LX-465M/182R-96+ GG 465 W 23.80% -0.260 23.5 kg +45 W, +2.2 pp, +5 yr warranty
SPR-MAX7-470 470 W 23.70% -0.270 21.1 kg +50 W, +2.1 pp, +15 yr warranty
AIKO-A470-MAH54Mb 470 W 23.60% -0.260 21.5 kg +50 W, +2.0 pp, +5 yr warranty
AIKO-A460-MAH54Mb 460 W 23.60% -0.290 20.5 kg Hotter, +2.0 pp, +5 yr warranty
HSM-BD54-LA470 470 W 23.60% -0.260 21.5 kg +50 W, +2.0 pp, +5 yr warranty
REC400AA PURE 2 400 W 20.60% -0.240 21.7 kg -20 W, -1.0 pp
REC410AA PURE 2 410 W 21.10% -0.240 21.7 kg -10 W, -0.5 pp
REC430AA PURE 2 430 W 22.20% -0.240 21.7 kg +10 W, +0.6 pp
LR7-54HJD-510M 510 W 25.00% -0.240 23.5 kg +90 W, +3.4 pp, +5 yr warranty
LR7-54HJD-505M 505 W 24.70% -0.240 23.5 kg +85 W, +3.1 pp, +5 yr warranty
WST-505BKX54-A2 505 W 24.70% -0.260 25.0 kg +85 W, +3.1 pp, +5 yr warranty
LR7-54HJD-500M 500 W 24.50% -0.240 23.5 kg +80 W, +2.9 pp, +5 yr warranty
CIPRO-TN9C54M-500W 500 W 24.50% -0.260 21.4 kg +80 W, +2.9 pp, +5 yr warranty
GK-3-54HGb-500M 500 W 24.50% -0.260 21.4 kg +80 W, +2.9 pp, +5 yr warranty

Found 9 panels of the same or similar size to this one, within ±10 mm. See them here Found 43 panels of the same or similar size to this one, within ±25 mm. See them here Found 96 panels of the same or similar size to this one, within ±50 mm. See them here Found 1941 panels of the same or similar size to this one, within ±100 mm. See them here

About the REC ALPHA® PURE 2 series

6 answered

These answers cover the whole series. Where a figure differs, the specification above is this module's own.

What does HJT technology in the REC Alpha Pure 2 mean, and why is it better than PERC?
HJT (heterojunction technology) combines a crystalline silicon core with amorphous silicon layers, achieving up to 22.3% module efficiency. The critical advantage over PERC is a much lower temperature coefficient of only -0.24%/°C versus approximately -0.4%/°C for typical PERC panels. In practice, this means less power loss on hot days and higher annual energy yield. The REC Alpha Pure 2 pairs HJT cells with a bifacial layout, further boosting the output of the entire system.
What does the REC Alpha Pure 2 warranty cover and for how long?
The REC Alpha Pure 2 comes with a 25-year product warranty and a 25-year power warranty, guaranteeing at least 92% of rated output at year 25. Through the REC ProTrust program, installations completed by a certified REC partner also include labor cost coverage. This makes it one of the most comprehensive warranty packages available in the residential PV market, backed by a Tier 1 Norwegian manufacturer.
How do REC Alpha Pure 2 panels handle partial shading on a roof?
The REC Alpha Pure 2 uses Twin Design architecture, which splits the module into two independent electrical sections. When a chimney, dormer, or antenna shades part of the panel, only half of the module is power-constrained - the other section continues operating at full capacity. Combined with 132 half-cut HJT cells, shading-related losses are significantly lower compared to conventional full-cell modules without section splitting.
Do the 430 Wp REC Alpha Pure 2 panels lose a lot of power on hot summer days?
No - this is one of HJT's strongest real-world advantages. The power temperature coefficient is just -0.24%/°C. At a panel operating temperature of 65°C (realistic in summer), the module loses roughly 9.6% of rated power, while a typical PERC panel in the same conditions would lose around 16%. In practice, the REC Alpha Pure 2 delivers noticeably higher energy output on hot days compared to most panels in this class.
Does the bifacial design of the REC Alpha Pure 2 make sense for a pitched roof installation?
Yes, though the gain depends on the roof surface color. The rear glass captures light reflected from the roof underlayment or surroundings. On light-colored membranes, white underlays, or bright facades, the bifacial effect can add a few percent of extra generation. On dark tiles the gain is more modest, but the HJT cells deliver excellent efficiency regardless of mounting configuration, keeping the system's value high in any scenario.
Why is the REC Alpha Pure 2 marketed as lead-free, and does it matter in practice?
The REC Alpha Pure 2 is one of the few residential modules manufactured entirely without lead, fully complying with the EU RoHS directive. This is relevant for safe end-of-life recycling after 25 years and for legal compliance as EU environmental regulations continue to tighten. For homeowners and businesses with ESG commitments, it is a meaningful differentiator from the vast majority of competing panels currently available on the market.
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