--- title: "REC REC640AA Pro MG 640W Solar Panel - Specs & Review | ComparePV" description: "REC REC640AA Pro MG 640W solar panel. Specs: 22.50% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/rec-rec640aa-pro-mg" updated: 2026-09-11 --- # REC REC640AA Pro MG Middle of its segment, heavy for its output 76 panels in the segment HJT 600-650 W ## Identity - **Manufacturer:** REC - **Model:** REC640AA Pro MG - **Series:** REC Alpha Pro MG Series - **Rated power:** 640 W - **Cell technology:** HJT - **Bifacial:** yes ## How it compares Compared against segment HJT 600-650 W (76 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 640 W | 625 W | Strong - top 13% | | | Module efficiency | 22.50% | 22.60% | Typical | 4,222 | | Power density | 225.5 | 225.8 | Typical | 3,889 | | Temperature coefficient | -0.240 | -0.240 | Typical | 13 | | Weight (kg) | 36.8 kg | 33.6 kg | Weak - bottom 16% | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 22.50% | 22.60% | Typical | 4,222 | | Power density | 225.5 | 225.8 | Typical | 3,889 | | Temperature coefficient | -0.240 | -0.240 | Typical | 13 | | Weight per kWp | 57.5 | 54.7 | Weak - bottom 16% | 11,246 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Watch out for - **57.5 kg per kWp** - Bottom 16% of the HJT 600-650 W segment, against a median of 54.7. - **Best for:** Commercial, utility-scale and hot-climate. - **Not ideal for:** Weight-limited structures. ## Specification ### Electrical - **Rated power (Pmax):** 640 W - **Efficiency:** 22.50 % - **Voltage at Pmax (Vmp):** 37.10 V - **Current at Pmax (Imp):** 17.26 A - **Open-circuit voltage (Voc):** 44.90 V - **Short-circuit current (Isc):** 17.89 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.240 %/degC - **Temperature coefficient of Voc:** -0.230 %/degC - **Temperature coefficient of Isc:** 0.040 %/degC - **NOCT:** 44 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** HJT - **Cell count:** 120 - **Bifacial:** yes ### Physical - **Length:** 2175 mm - **Width:** 1305 mm - **Thickness:** 30 mm - **Weight:** 36.8 kg - **Area:** 2.84 m2 - **Power density:** 225.5 Wp/m2 ### Warranty and degradation - **Product warranty:** 30 years - **Performance warranty:** 30 years - **Output guaranteed at end of warranty:** 90.8 % - **First-year degradation:** 2.00 % - **Annual degradation:** 0.25 % - **Output after 30 years:** 581 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 4222 of 14005 | | Power density | 3889 of 14005 | | Temperature coefficient | 13 of 14005 | | Weight | 11246 of 14005 | | Warranty | 21 of 14005 | ## Pros - **Dual-glass boosts durability** - Glass-glass construction instead of a standard backsheet improves resistance to moisture ingress, microcracks, and UV degradation, extending module lifespan in demanding operating conditions such as heated industrial rooftops. - **HJT with low temperature coefficient** - A power temperature coefficient of roughly -0.24%/°C (per manufacturer data for the Alpha Pro family) means lower output losses at high operating temperatures compared to typical PERC modules, which matters for installations on hot membrane roofs. - **30-year product and power warranty** - The manufacturer offers 30 years of both product and power warranty (min. 90.75% of rated power after 30 years) - notably longer than the standard 25 years offered by most peer comparables in this segment. - **Bifacial design boosts energy yield** - Dual-sided HJT cells capture light reflected from the ground, adding extra energy yield in ground-mount installations, on light-colored membrane roofs, and in elevated racking systems versus monofacial designs. - **Tier-1 manufacturer since 1996, Norway HQ** - REC is a bankable Tier-1 manufacturer with over 25 years of module production experience, reducing service-contract risk and easing project financing for C&I and utility-scale PV farms. ## Cons - **Efficiency trails comparable 640 Wp modules** - Peak efficiency of this series is 22.5%, while comparable 640 Wp modules from competitors reach higher figures: Jinko EAGLE G7B 23.69%, Jetion JT SRt(B) 22.9%, and Luxen N6 22.61%. At the same peak power, this means slightly more installation area is needed for the same energy yield. ## About this series The REC Alpha Pro MG series consists of glass-glass modules designed for installations where maximizing energy yield per square meter and predictable performance over many years are crucial. The use of **two-sided heterojunction (HJT) cells** allows for reduced losses at high temperatures and more stable energy production in challenging conditions, such as on heated roof surfaces. The **bifacial** design also utilizes reflected light from the ground, which is a significant advantage in ground-mounted installations, on reflective membrane roofs, or in elevated systems. Another key feature of this series is the **glass on both sides** - it enhances resistance to environmental factors and improves durability compared to many standard modules with a backsheet. For business investors, the **longer warranty period for power output** is a key factor, facilitating energy cost planning and risk management. The REC Alpha Pro MG is an excellent choice for PV farms and commercial and industrial (C&I) applications, where reliability, performance in warm conditions, and the additional yield from bifaciality are priorities. ## Notable figures - At 22.5% efficiency, this panel is on par with typical \*\*HJT 600-650W\*\* modules - Power density of 225.5 W/m² matches the \*\*HJT 600-650W\*\* median - Temperature coefficient of -0.24%/°C matches the \*\*HJT 600-650W\*\* median - Weight of 36.8 kg is 3.2 kg above \*\*HJT 600-650W\*\* median (33.6 kg) - verify structural support - Bifaciality factor of 86% can add 4-13% extra yield with reflective mounting surface ## Questions ### What is the power warranty on REC Alpha Pro MG panels and what does it actually cover? The REC Alpha Pro MG Series comes with a 30-year product warranty and a 30-year power output warranty. Per REC's warranty terms, after 30 years the panel must retain at least 90.75% of its nameplate power, with annual degradation capped at 0.25% from year two onward. This is among the longest warranties in the C&I module segment and makes it straightforward to model LCOE across the full investment horizon. ### Why do HJT panels in the REC Alpha Pro MG Series perform better in summer on hot industrial rooftops? HJT cells carry a temperature coefficient of -0.24%/°C, which is among the lowest available in silicon PV. That means for every 10°C rise in module temperature the panel loses significantly less power than standard PERC cells (-0.35%/°C). On sun-heated industrial roofs this translates into a measurably higher annual energy yield with no additional hardware investment. ### Does the glass-glass construction of the REC Alpha Pro MG actually extend panel lifespan? Yes. Replacing the polymer backsheet with a rear glass pane eliminates the main causes of premature module aging: backsheet cracking, delamination, and moisture ingress. The glass-glass structure also improves mechanical strength and PID (potential induced degradation) resistance. This matters most in ground-mount and commercial rooftop installations with 20-plus-year payback horizons where long-term reliability is critical. ### What real-world bifacial gain can I expect from REC Alpha Pro MG panels in a ground-mount system? With a bifaciality factor above 70%, and proper mounting height over a high-albedo surface (sand, light gravel, white membrane), the additional energy yield from the rear side typically ranges from 5% to 15%, depending on ground albedo and tilt angle. On utility-scale PV farms with light-colored ground cover or flat commercial roofs with white TPO/PVC membrane, this bifacial gain can translate into a meaningfully lower LCOE compared to monofacial modules at the same STC rating. ### Are the 640 Wp REC Alpha Pro MG panels suitable for a typical C&I installation, and how should they be connected to an inverter? The REC Alpha Pro MG 640 Wp is purpose-built for C&I and utility-scale PV, not residential prosumer use. The open-circuit voltage (Voc) is approximately 44.9 V with a maximum system voltage of 1500 V DC. Modules are wired in series strings sized to match the MPPT window of a compatible three-phase string or central inverter rated for 1500 V. Always verify string length against the inverter's technical datasheet before system design. ### How does the REC Alpha Pro MG Series differ from the more popular REC Alpha Pure-R aimed at residential customers? The REC Alpha Pure-R targets residential prosumers with power outputs up to around 470 W, compact dimensions, and a sleek all-black aesthetic. The REC Alpha Pro MG is positioned for C&I and utility-scale: up to 640 Wp, glass-glass construction, a 30-year warranty, and bifacial optimization for ground-mount and large industrial rooftop installations. Both series share HJT cell technology but differ significantly in power class, module format, and target application. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/ds-rec-alpha-pro-mg-iec-en-au-f21eb91a31c8.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Hotter, lighter, +2.7 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +40 W, lighter, +2.7 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +35 W, lighter, +2.5 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Hotter, lighter, +2.5 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | +30 W, lighter, +2.3 pp | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | +30 W, lighter, +2.3 pp | | [AIKO AIKO-A640-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a640-mae72mw) | 640 W | Hotter, lighter, +2.3 pp | | [REC REC590AA Pro MG](https://comparepv.com/panel/rec-rec590aa-pro-mg) | 590 W | -50 W, -1.7 pp | | [REC REC600AA PRO M](https://comparepv.com/panel/rec-rec600aa-pro-m) | 600 W | Lighter, -1.4 pp, -5 yr warranty | | [REC REC610AA PRO M](https://comparepv.com/panel/rec-rec610aa-pro-m) | 610 W | Lighter, -1.0 pp, -5 yr warranty | | [REC REC620AA PRO M](https://comparepv.com/panel/rec-rec620aa-pro-m) | 620 W | Lighter, -0.7 pp, -5 yr warranty | | [REC REC630AA PRO M](https://comparepv.com/panel/rec-rec630aa-pro-m) | 630 W | Lighter, -0.3 pp, -5 yr warranty | | [Gamko New Energy GKA210N120](https://comparepv.com/panel/gamko-new-energy-gka210n120) | 680 W | Hotter, lighter, +1.5 pp | | [Gamko New Energy GKA210N120-675](https://comparepv.com/panel/gamko-new-energy-gka210n120-675) | 675 W | Hotter, lighter, +1.4 pp | | [Q-SUN Solar QN-670HJT-01](https://comparepv.com/panel/q-sun-solar-qn-670hjt-01) | 670 W | +30 W, lighter, +1.2 pp | | [Gamko New Energy GKA210N120-670](https://comparepv.com/panel/gamko-new-energy-gka210n120-670) | 670 W | Hotter, lighter, +1.2 pp | --- Source: https://comparepv.com/panel/rec-rec640aa-pro-mg Not in this file, on the page: a thirty-year output simulator, a bifacial gain calculator and alternatives filtered by how closely they match these dimensions.