--- title: "Powitt Solar PW-66M635HM10L-BD 635W Solar Panel - Specs & Review | ComparePV" description: "Powitt Solar PW-66M635HM10L-BD 635W solar panel. Specs: 23.51% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/powitt-solar-pw-66m635hm10l-bd" updated: 2026-09-11 --- # Powitt Solar PW-66M635HM10L-BD Efficiency leader, no clear weak spot 359 panels in the segment N-type 600-650 W ## Identity - **Manufacturer:** Powitt Solar - **Model:** PW-66M635HM10L-BD - **Series:** MONO MODULE N-TYPE Bifacial Dual Glass - **Rated power:** 635 W - **Cell technology:** N-type - **Bifacial:** yes ## How it compares Compared against segment N-type 600-650 W (359 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 635 W | 625 W | Strong - top 22% | | | Module efficiency | 23.51% | 22.77% | Strong - top 10% | 696 | | Power density | 235.1 | 227.7 | Strong - top 12% | 741 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight (kg) | 32.5 kg | 32.5 kg | Typical | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 23.51% | 22.77% | Strong - top 10% | 696 | | Power density | 235.1 | 227.7 | Strong - top 12% | 741 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight per kWp | 51.2 | 52.7 | Typical | 4,557 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Strengths - **23.51% module efficiency** - Top 10% of the N-type 600-650 W segment, against a median of 22.77%. Ranked 696th in the whole database. - **235.1 watts per square metre** - Top 12% of the N-type 600-650 W segment, against a median of 227.7. - **Best for:** Residential, commercial, utility-scale and hot-climate. ## Specification ### Electrical - **Rated power (Pmax):** 635 W - **Efficiency:** 23.51 % - **Voltage at Pmax (Vmp):** 41.80 V - **Current at Pmax (Imp):** 15.20 A - **Open-circuit voltage (Voc):** 49.00 V - **Short-circuit current (Isc):** 16.26 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.290 %/degC - **Temperature coefficient of Voc:** -0.250 %/degC - **Temperature coefficient of Isc:** 0.050 %/degC - **NOCT:** 41 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** N-type - **Cell count:** 132 - **Bifacial:** yes - **Bifacial gain:** 10.00 ### Physical - **Length:** 2382 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 32.5 kg - **Area:** 2.70 m2 - **Power density:** 235.1 Wp/m2 ### Warranty and degradation - **Product warranty:** 15 years - **Performance warranty:** 30 years - **Output guaranteed at end of warranty:** 87.4 % - **First-year degradation:** 1.00 % - **Annual degradation:** 0.40 % - **Output after 30 years:** 555 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 696 of 14005 | | Power density | 741 of 14005 | | Temperature coefficient | 2165 of 14005 | | Weight | 4557 of 14005 | | Warranty | 21 of 14005 | ## Pros - **Highest efficiency in peer segment** - Efficiency of 23.14-23.69% exceeds direct competitors: REC Alpha Pro M (22.5%) and Jetion JT SRt(B) (22.9%), and matches the top Luxen N5 series. Higher efficiency translates into fewer modules needed to reach the same installation capacity. - **N-type TOPCon cell technology** - N-type TOPCon cells nearly eliminate light-induced degradation (LID) and have a lower temperature coefficient than older PERC cells, ensuring a more stable energy yield in hot climates and over the full operational lifetime. - **Bifacial dual-glass construction** - The dual-sided design allows additional energy harvest from reflected (albedo) radiation, particularly valuable on light-colored roofing or ground-mount farms, while the tempered dual-glass structure significantly boosts mechanical resistance to hail, wind, and snow load versus back-sheet modules. - **High per-unit power up to 640 Wp** - Power output up to 640 Wp matches the strongest peer models (Luxen N5 640 Wp, REC Alpha Pro M 640 Wp, Jetion JT SRt(B) 640 Wp), reducing the module count, cabling, and mounting structure required per kWp of installed capacity. - **30-year linear power warranty** - A 30-year linear power warranty exceeds the standard 25-year terms common in this segment, lowering long-term risk of energy output decline and supporting a lower levelized cost of energy (LCOE). ## Cons - **Manufacturer not BNEF Tier 1 listed** - Powitt Solar does not hold BNEF (Bloomberg New Energy Finance) Tier 1 Bankable status, unlike some reputable competitors in this segment, which can complicate non-recourse bank financing for large commercial projects and limit insurer acceptance. - **Shorter product warranty than market leader REC** - The 15-year product warranty is notably shorter than REC's 25-year product warranty for the Alpha Pro M series, which may be a meaningful factor when comparing total service risk in long-term projects. ## About this series The Powitt Solar MONO MODULE N-TYPE Bifacial Dual Glass solar panel series sets new efficiency standards thanks to the use of advanced **N-Type TOPCon cell technology**. Unlike traditional solutions, these modules almost completely eliminate the negative phenomenon of light-induced degradation (LID), which guarantees investors stable energy yields for decades. A key feature of the series is the **Bifacial double-sided design**, which allows for additional power generation from radiation reflected from the ground, making it particularly cost-effective for ground-mounted farms or bright roof surfaces. The use of a **Dual Glass structure**, meaning double tempered glass, significantly increases the mechanical resistance of the panels to extreme weather conditions such as hail, strong winds, or snow loads, while simultaneously protecting the cells from micro-cracks and chemical corrosion. This product is dedicated to demanding business investors and owners of single-family homes who prioritize maximizing self-consumption and long-term savings. Thanks to **low temperature coefficients**, the panels maintain high efficiency even on hot days, which sets them apart from standard competition. Choosing this series is an investment in **maximum durability and efficiency**, backed by a long-term power warranty, which solves the problem of premature component aging and ensures the lowest levelized cost of energy (LCOE). ## Notable figures - At 23.5% efficiency, this panel is 0.7pp above typical \*\*N-type 600-650W\*\* modules (median: 22.8%) - Power density of 235.1 W/m² packs 7.4 W/m² more into the same footprint vs \*\*N-type 600-650W\*\* median (227.7 W/m²) - Temperature coefficient of -0.29%/°C matches the \*\*N-type 600-650W\*\* median - Bifaciality factor of 86% can add 4-13% extra yield with reflective mounting surface - #696 for efficiency, #2165 for temperature performance out of 14005 panels ## Questions ### How do Powitt Solar MONO MODULE N-TYPE Bifacial Dual Glass panels differ from standard P-Type PERC modules? The key difference is N-type TOPCon cell technology instead of conventional P-type PERC. N-type cells nearly eliminate Light Induced Degradation (LID), ensuring more stable energy yields throughout the module's lifetime. The bifacial design enables power generation from both sides of the panel, while the Dual Glass structure provides superior protection against moisture ingress and microcracks compared to a standard polymer backsheet. ### Are Powitt Solar 640 Wp bifacial panels a good choice for a ground-mounted system? Yes, the bifacial design is especially advantageous in ground-mounted systems. The rear glass captures albedo radiation reflected from the ground surface, which — depending on mounting height and surface reflectivity — can boost energy output by several percentage points versus a monofacial module. The 640 Wp peak power also means fewer modules are required for large-scale installations, directly reducing BoS costs. ### What warranty does the Powitt Solar N-TYPE Bifacial Dual Glass series carry? Powitt Solar provides a 15-year product warranty covering manufacturing and material defects, plus a 30-year linear power warranty. Thanks to the low annual degradation rate typical of N-type TOPCon technology, modules are expected to retain well above 80% of rated power after 30 years, delivering a highly competitive LCOE over the full system lifetime. ### What are the real-world advantages of Dual Glass construction over a standard backsheet? Dual Glass replaces the polymer backsheet with a second tempered glass sheet, essentially eliminating water vapor transmission and protecting cells from corrosion and delamination for decades. The glass also handles higher mechanical loads from hail, wind pressure, and snow accumulation than standard backsheets. The slight weight increase is offset by significantly better long-term durability and electrical stability of the module. ### Do Powitt Solar N-Type 640 Wp panels lose significant output on hot summer days? All PV modules experience power loss at elevated temperatures, but N-type TOPCon cells have a lower temperature coefficient than P-type PERC modules. In practice this means less output degradation when cell temperatures exceed 50-70°C on hot sunny days — a meaningful advantage for rooftop installations with limited airflow or utility-scale ground-mount systems in high-irradiance locations. ### How many Powitt Solar 640 Wp modules do I need to build a 10 kWp system? At 640 Wp per module, 16 panels yield exactly 10.24 kWp. The system designer will fine-tune module count to match the inverter's MPPT input range and available area. The high per-module wattage means fewer modules than with popular 400-500 Wp formats, which directly lowers BoS costs — mounting hardware, DC cabling, and installation labor — for the same system output. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/2025-03-10-powitt-182-210mm-132half-cell-625-640w-ntype-bd-f6d9080cb78c.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, lighter, +1.7 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +45 W, lighter, +1.7 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +40 W, lighter, +1.5 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +1.5 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | +35 W, lighter, +1.3 pp | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | +35 W, lighter, +1.3 pp | | [AIKO AIKO-A640-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a640-mae72mw) | 640 W | Cooler, lighter, +1.3 pp | | [Powitt Solar PW-66M625HM10L-BD](https://comparepv.com/panel/powitt-solar-pw-66m625hm10l-bd) | 625 W | -10 W, -0.4 pp | | [Powitt Solar PW-66M630HM10L-BD](https://comparepv.com/panel/powitt-solar-pw-66m630hm10l-bd) | 630 W | Very close match | | [Powitt Solar PW-66M640HM10L-BD](https://comparepv.com/panel/powitt-solar-pw-66m640hm10l-bd) | 640 W | Very close match | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +65 W, cooler, +1.5 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +60 W, cooler, +1.4 pp | | [Jinko Solar JKM650-670N-66QL6-BDV (670W class)](https://comparepv.com/panel/jinko-solar-jkm650-670n-66ql6-bdv-670w-class) | 670 W | +35 W, cooler, +1.3 pp | --- Source: https://comparepv.com/panel/powitt-solar-pw-66m635hm10l-bd Not in this file, on the page: the I-V and temperature curves lifted from the manufacturer's datasheet, a thirty-year output simulator, a bifacial gain calculator and alternatives filtered by how closely they match these dimensions.