--- title: "REC REC400AA PURE 2 Solar Panel: Specs & Datasheet | ComparePV" description: "REC REC400AA PURE 2 solar panel. Specs: 20.60% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/rec-rec400aa-pure-2" image: "https://comparepv.com/og/panel/rec-rec400aa-pure-2.png" updated: 2026-09-11 --- # REC REC400AA PURE 2 Middle of its segment, short guarantee 113 panels in the segment HJT 400-450 W ## Identity - **Manufacturer:** REC - **Model:** REC400AA PURE 2 - **Series:** REC ALPHA® PURE 2 - **Rated power:** 400 W - **Cell technology:** HJT - **Bifacial:** yes ## How it compares Compared against segment HJT 400-450 W (113 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 400 W | 435 W | Weak - bottom 4% | | | Module efficiency | 20.60% | 22.20% | Weak - bottom 10% | 11,172 | | Power density | 206.2 | 221.6 | Weak - bottom 9% | 11,150 | | Temperature coefficient | -0.240 | -0.240 | Typical | 13 | | Weight (kg) | 21.7 kg | 23.0 kg | Typical | | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 8% | 9,912 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 20.60% | 22.20% | Weak - bottom 10% | 11,172 | | Power density | 206.2 | 221.6 | Weak - bottom 9% | 11,150 | | Temperature coefficient | -0.240 | -0.240 | Typical | 13 | | Weight per kWp | 54.2 | 52.4 | Typical | 8,576 | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 8% | 9,912 | ### Watch out for - **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. - **206.2 watts per square metre** - Bottom 9% of the HJT 400-450 W segment, against a median of 221.6. Ranked 11,150th in the whole database. - **20.60% module efficiency** - Bottom 10% of the HJT 400-450 W segment, against a median of 22.20%. Ranked 11,172nd in the whole database. - **Best for:** Residential, commercial, shaded-installations and hot-climate. - **Not ideal for:** Owners who want a long output guarantee, roofs where every square metre has to count and tight roof space. ## Specification ### Electrical - **Rated power (Pmax):** 400 W - **Efficiency:** 20.60 % - **Voltage at Pmax (Vmp):** 40.20 V - **Current at Pmax (Imp):** 9.96 A - **Open-circuit voltage (Voc):** 48.50 V - **Short-circuit current (Isc):** 10.72 A - **Max system voltage:** 1000 V ### Temperature - **Temperature coefficient of Pmax:** -0.240 %/degC - **Temperature coefficient of Voc:** -0.240 %/degC - **Temperature coefficient of Isc:** 0.040 %/degC - **NOCT:** 44 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** HJT - **Cell count:** 132 - **Bifacial:** yes ### Physical - **Length:** 1865 mm - **Width:** 1040 mm - **Thickness:** 30 mm - **Weight:** 21.7 kg - **Area:** 1.94 m2 - **Power density:** 206.2 Wp/m2 ### Warranty and degradation - **Product warranty:** 25 years - **Performance warranty:** 25 years - **Output guaranteed at end of warranty:** 92.0 % - **First-year degradation:** 2.00 % - **Annual degradation:** 0.25 % - **Output after 30 years:** 363 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 11172 of 14129 | | Power density | 11150 of 14129 | | Temperature coefficient | 13 of 14129 | | Weight | 8576 of 14129 | | Warranty | 9912 of 14129 | ## Pros - **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. ## Cons - **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. ## About this series 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. ## Notable figures - Efficiency of 20.6% is 1.6pp below the \*\*HJT 400-450W\*\* median (22.2%) - At 206.2 W/m², this panel generates 15.4 W/m² less per unit area than \*\*HJT 400-450W\*\* median (221.6 W/m²) - 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 - #11172 for efficiency, #13 for temperature performance out of 14129 panels ## Questions ### 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. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/Web_DS_REC_Alpha_Pure_2_UL_EN_US_12122024-f96502433dee.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [Luxor Solar LX-440M/182-108+GG](https://comparepv.com/panel/luxor-solar-lx-440m-182-108-gg) | 440 W | +40 W, +2.5 pp, +5 yr warranty | | [Just Solar JST-EDMH-(445-465)W-TD (450W class)](https://comparepv.com/panel/just-solar-jst-edmh-445-465-w-td-450w-class) | 450 W | +50 W, hotter, +2.4 pp | | [Q-SUN Solar QNN182-HG450-54](https://comparepv.com/panel/qn-solar-pv-limited-qnn182-hg450-54) | 450 W | +50 W, +2.4 pp, +5 yr warranty | | [Huayao HY440-N108BDD](https://comparepv.com/panel/huayao-hy440-n108bdd) | 450 W | +50 W, hotter, +2.4 pp | | [BYD NLBK-27-450](https://comparepv.com/panel/byd-nlbk-27-450) | 450 W | +50 W, hotter, +2.4 pp | | [Renesola RS41-450NBG-E3](https://comparepv.com/panel/renesola-rs41-450nbg-e3) | 450 W | +50 W, +2.4 pp, +5 yr warranty | | [REC REC410AA PURE 2](https://comparepv.com/panel/rec-rec410aa-pure-2) | 410 W | +10 W, +0.5 pp | | [REC REC420AA PURE 2](https://comparepv.com/panel/rec-rec420aa-pure-2) | 420 W | +20 W, +1.0 pp | | [REC REC430AA PURE 2](https://comparepv.com/panel/rec-rec430aa-pure-2) | 430 W | +30 W, +1.6 pp | | [Longi Solar LR7-54HJD-510M](https://comparepv.com/panel/longi-lr7-54hjd-510m) | 510 W | +110 W, +4.4 pp, +5 yr warranty | | [Longi Solar LR7-54HJD-505M](https://comparepv.com/panel/longi-lr7-54hjd-505m) | 505 W | +105 W, +4.1 pp, +5 yr warranty | | [WINAICO WST-505BKX54-A2](https://comparepv.com/panel/winaico-wst-505bkx54-a2) | 505 W | +105 W, +4.1 pp, +5 yr warranty | | [Longi Solar LR7-54HJD-500M](https://comparepv.com/panel/longi-lr7-54hjd-500m) | 500 W | +100 W, +3.9 pp, +5 yr warranty | | [Talesun CIPRO-TN9C54M-500W](https://comparepv.com/panel/talesun-cipro-tn9c54m-500w) | 500 W | +100 W, +3.9 pp, +5 yr warranty | | [Gokin GK-3-54HGb-500M](https://comparepv.com/panel/gokin-gk-3-54hgb-500m) | 500 W | +100 W, +3.9 pp, +5 yr warranty | --- Source: https://comparepv.com/panel/rec-rec400aa-pure-2 Not in this file, on the page: the I-V and temperature curves lifted from the manufacturer's datasheet, a thirty-year output simulator and alternatives filtered by how closely they match these dimensions.