--- title: "Phono Solar NS-640MH-120 640W Solar Panel - Specs & Review | ComparePV" description: "Phono Solar NS-640MH-120 640W solar panel. Specs: 22.61% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/phono-solar-ns-640mh-120" updated: 2026-09-11 --- # Phono Solar NS-640MH-120 Middle of its segment, short guarantee 359 panels in the segment N-type 600-650 W ## Identity - **Manufacturer:** Phono Solar - **Model:** NS-640MH-120 - **Series:** Monocrystalline120 - **Rated power:** 640 W - **Cell technology:** N-type ## How it compares Compared against segment N-type 600-650 W (359 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 640 W | 625 W | Strong - top 11% | | | Module efficiency | 22.61% | 22.77% | Typical | 3,643 | | Power density | 226.1 | 227.7 | Typical | 3,681 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight (kg) | 31.0 kg | 32.5 kg | Typical | | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 4% | 9,798 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 22.61% | 22.77% | Typical | 3,643 | | Power density | 226.1 | 227.7 | Typical | 3,681 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight per kWp | 48.4 | 52.7 | Typical | 2,274 | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 4% | 9,798 | ### Watch out for - **25 year performance warranty** - Bottom 4% of the N-type 600-650 W segment, against a median of 30 yrs. Ranked 9,798th in the whole database. - **Best for:** Commercial, utility-scale and shaded-installations. - **Not ideal for:** Owners who want a long output guarantee. ## Specification ### Electrical - **Rated power (Pmax):** 640 W - **Efficiency:** 22.61 % - **Voltage at Pmax (Vmp):** 37.66 V - **Current at Pmax (Imp):** 17.00 A - **Open-circuit voltage (Voc):** 45.19 V - **Short-circuit current (Isc):** 17.70 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:** 0.045 %/degC - **NOCT:** 45 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** N-type - **Cell count:** 120 ### Physical - **Length:** 2172 mm - **Width:** 1303 mm - **Thickness:** 30 mm - **Weight:** 31.0 kg - **Area:** 2.83 m2 - **Power density:** 226.1 Wp/m2 ### Warranty and degradation - **Product warranty:** 15 years - **Performance warranty:** 25 years ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 3643 of 14005 | | Power density | 3681 of 14005 | | Temperature coefficient | 2165 of 14005 | | Weight | 2274 of 14005 | | Warranty | 9798 of 14005 | ## Pros - **N-type cells with half-cut design** - 120 half-cut N-type cells reduce resistive losses and LID/LeTID degradation compared to older P-type technology, and splitting each cell in half limits the impact of partial shading on overall module output. - **Long-established Tier-1 manufacturer** - Phono Solar has operated since 2004 and has repeatedly been confirmed on BloombergNEF's Tier 1 'bankability' list, which eases project financing through banks and lending institutions. - **Power output up to 660 Wp matches segment leaders** - The 660 Wp upper power limit matches flagship series from competitors like Longi Hi-MO 9 and Canadian Solar TOPBiHiKu6, despite the Monocrystalline120 series dating back to 2018 and not using the latest cell generations. - **Enhanced mechanical durability and sealing** - The manufacturer highlights refined micro-crack resistance and a sealed, high-IP-rated junction box, relevant for roof installations exposed to moisture and wide temperature swings typical of the Polish climate. - **Documented field track record** - The series was produced from 2018 to 2023, providing several years of real-world field performance data - unlike newly launched series that lack a long-term operational history. ## Cons - **Production discontinued in 2023** - The Monocrystalline120 series has been phased out (end\_year: 2023), meaning limited availability of spare parts and more difficult warranty servicing for individual module failures over the long term. - **Efficiency lags behind leading N-type peers** - Maximum efficiency of 23.32% is roughly 1.08 pp lower than Longi Hi-MO 9 (24.4%) or Canadian Solar TOPBiHiKu6 (24.4%), translating to a somewhat lower energy yield for the same roof area. - **No bifacial variant available** - Unlike some comparable series from competitors (e.g., Canadian Solar TOPBiHiKu6), Monocrystalline120 does not offer bifacial modules, ruling out an additional 5-15% albedo-driven yield gain on ground-mount or high-reflectivity roof installations. - **25-year power warranty below the current standard** - The linear power warranty is capped at 25 years, shorter than the 30-year warranties Phono Solar already offers on newer series (e.g., PS590M8GF-24 guaranteeing 87.4% power at year 30), making this series less competitive against current N-type market offerings. ## About this series The Phono Solar Monocrystalline 120 series consists of modules based on **120 half-cut cells**, designed to operate reliably even when part of the cell is intermittently shaded (e.g., by a chimney, skylight, or tree). The use of **mono PERC technology** improves light absorption and supports energy generation in weaker lighting conditions, which, in the Polish climate, translates into more predictable energy production in spring, autumn, and on cloudy days. The half-cut design reduces resistance losses and reduces the risk of localized overheating, allowing the module to maintain its parameters for longer. This is a good choice for residential and small commercial installations, where the trade-off between the power of a single panel and ease of installation is important. A key advantage over many competitors is the **refined resistance to micro-cracks** and the **watertight junction box with a high level of protection**, which makes it easier to operate on roofs exposed to moisture and large temperature variations. ## Notable figures - Efficiency of 22.6% matches the \*\*N-type 600-650W\*\* median - At 226.1 W/m² power density, roof space requirements are typical for \*\*N-type 600-650W\*\* panels - At -0.29%/°C, hot weather performance is typical for \*\*N-type 600-650W\*\* panels - 31.0 kg weight - 1.5 kg lighter than \*\*N-type 600-650W\*\* median (32.5 kg), reducing installation effort - In the top 26% for efficiency among all N-type panels ## Questions ### Is the Phono Solar Monocrystalline120 series still available for purchase? The Phono Solar Monocrystalline120 series has been discontinued and is no longer actively offered by the manufacturer. Individual units may still be found at distributors clearing old stock, but purchasing carries a risk of limited availability for replacement panels in case of future failures. Buyers should consider a current Phono Solar series with active support and full component availability. ### What warranty does Phono Solar offer on the Monocrystalline120 series? The Monocrystalline120 series came with a 15-year product warranty covering material and manufacturing defects, and a 25-year linear power output warranty. This means the panel is guaranteed to retain at least the specified minimum efficiency over a quarter-century. Keep in mind that since the series is discontinued, enforcing warranty claims over the long term may be more difficult than with actively produced models. ### What advantage does N-type cell technology in the Phono Solar Monocrystalline120 offer over standard PERC? N-type cells exhibit lower light-induced degradation (LID) and higher efficiency under low-irradiance conditions compared to conventional p-type PERC. In practice this means better energy yield during spring, autumn, and overcast days common in Central European climates. N-type modules also degrade more slowly over time, resulting in a shallower power loss curve across the panel's operational lifetime. ### How do the 120 half-cut cells affect system performance under partial shading? The 120-cell half-cut layout splits the module into two independent electrical halves. When one section is shaded by a chimney or dormer window, the other half continues operating at full capacity, minimizing overall yield loss. Half-cut cells also reduce resistive losses due to lower in-cell current and decrease the risk of hot-spot formation, extending the long-term reliability of the module. ### What is the peak power output of the Phono Solar Monocrystalline120 and what installations is it suited for? The top variant of the series reaches 660 Wp, placing it in the high power-density segment. The series was designed for residential rooftops and small commercial installations where maximizing yield from a limited roof area is the priority. Its high unit output allows building the required system capacity with fewer panels, simplifying the racking structure and reducing installation labor. ### How well does the Phono Solar Monocrystalline120 handle the Polish climate and large temperature swings? The series was built for demanding weather conditions. The high-IP-rated junction box protects against moisture and heavy rainfall. Enhanced resistance to microcracks limits damage from thermal expansion and contraction caused by large daily temperature swings common in Poland. N-type cell technology also mitigates the power temperature coefficient effect, reducing output losses during hot summer days. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/ns-620-660mh-120-2172-1303-30-a9c2bc268fed.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Lighter, +2.6 pp, +5 yr warranty | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +40 W, +2.6 pp, +5 yr warranty | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +35 W, +2.4 pp, +5 yr warranty | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Lighter, +2.4 pp, +5 yr warranty | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | +30 W, +2.2 pp, +5 yr warranty | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | +30 W, +2.2 pp, +5 yr warranty | | [AIKO AIKO-A640-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a640-mae72mw) | 640 W | Lighter, +2.2 pp, +5 yr warranty | | [Phono Solar NS-620MH-120](https://comparepv.com/panel/phono-solar-ns-620mh-120) | 620 W | -20 W, -0.7 pp | | [Phono Solar NS-630MH-120](https://comparepv.com/panel/phono-solar-ns-630mh-120) | 630 W | -10 W, -0.3 pp | | [Phono Solar NS-650MH-120](https://comparepv.com/panel/phono-solar-ns-650mh-120) | 650 W | +10 W, +0.4 pp | | [Phono Solar NS-660MH-120](https://comparepv.com/panel/phono-solar-ns-660mh-120) | 660 W | +20 W, +0.7 pp | | [Gamko New Energy GKA210N120](https://comparepv.com/panel/gamko-new-energy-gka210n120) | 680 W | Hotter, +1.4 pp, +5 yr warranty | | [Gamko New Energy GKA210N120-675](https://comparepv.com/panel/gamko-new-energy-gka210n120-675) | 675 W | Hotter, +1.2 pp, +5 yr warranty | | [Q-SUN Solar QN-670HJT-01](https://comparepv.com/panel/q-sun-solar-qn-670hjt-01) | 670 W | Cooler, +1.1 pp, +5 yr warranty | | [Gamko New Energy GKA210N120-670](https://comparepv.com/panel/gamko-new-energy-gka210n120-670) | 670 W | Hotter, +1.1 pp, +5 yr warranty | | [Q-SUN Solar QN-665HJT-01](https://comparepv.com/panel/q-sun-solar-qn-665hjt-01) | 665 W | Cooler, heavier, +5 yr warranty | --- Source: https://comparepv.com/panel/phono-solar-ns-640mh-120 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.