--- title: "Phono Solar PS390M4-20/UH Solar Panel: Specs & Datasheet | ComparePV" description: "Phono Solar PS390M4-20/UH solar panel. Specs: 21.30% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/phono-solar-technology-co-ltd-ps390m4-20-uh" image: "https://comparepv.com/og/panel/phono-solar-technology-co-ltd-ps390m4-20-uh.png" updated: 2026-09-11 --- # Phono Solar PS390M4-20/UH Space saver, no clear weak spot 579 panels in the segment PERC 350-400 W ## Identity - **Manufacturer:** Phono Solar - **Model:** PS390M4-20/UH - **Series:** Twinplus Module Series (HIGH EFFICIENCY MONO-PERC M4-9B-R) - **Rated power:** 390 W - **Cell technology:** PERC ## How it compares Compared against segment PERC 350-400 W (579 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 390 W | 380 W | Typical | | | Module efficiency | 21.30% | 19.90% | Strong - top 1% | 8,585 | | Power density | 213.0 | 199.0 | Strong - top 1% | 8,554 | | Temperature coefficient | -0.340 | -0.350 | Strong - top 15% | 8,846 | | Weight (kg) | 20.0 kg | 21.4 kg | Strong - top 10% | | | Performance warranty | 25 yrs | 25 yrs | Typical | 9,912 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 21.30% | 19.90% | Strong - top 1% | 8,585 | | Power density | 213.0 | 199.0 | Strong - top 1% | 8,554 | | Temperature coefficient | -0.340 | -0.350 | Strong - top 15% | 8,846 | | Weight per kWp | 51.3 | 55.8 | Strong - top 10% | 4,694 | | Performance warranty | 25 yrs | 25 yrs | Typical | 9,912 | ### Strengths - **213.0 watts per square metre** - Top 1% of the PERC 350-400 W segment, against a median of 199.0. Ranked 8,554th in the whole database. - **21.30% module efficiency** - Top 1% of the PERC 350-400 W segment, against a median of 19.90%. Ranked 8,585th in the whole database. - **51.3 kg per kWp** - Top 10% of the PERC 350-400 W segment, against a median of 55.8. Ranked 4,694th in the whole database. - **Best for:** Residential, commercial and shaded-installations. ## Specification ### Electrical - **Rated power (Pmax):** 390 W - **Efficiency:** 21.30 % - **Voltage at Pmax (Vmp):** 35.14 V - **Current at Pmax (Imp):** 11.10 A - **Open-circuit voltage (Voc):** 41.74 V - **Short-circuit current (Isc):** 11.69 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.340 %/degC - **Temperature coefficient of Voc:** -0.270 %/degC - **Temperature coefficient of Isc:** 0.045 %/degC - **NOCT:** 45 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** PERC - **Cell count:** 120 ### Physical - **Length:** 1762 mm - **Width:** 1039 mm - **Thickness:** 30 mm - **Weight:** 20.0 kg - **Area:** 1.83 m2 - **Power density:** 213.0 Wp/m2 ### Warranty and degradation - **Product warranty:** 12 years - **Performance warranty:** 25 years - **Output guaranteed at end of warranty:** 84.8 % - **First-year degradation:** 2.00 % - **Annual degradation:** 0.55 % - **Output after 30 years:** 320 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 8585 of 14129 | | Power density | 8554 of 14129 | | Temperature coefficient | 8846 of 14129 | | Weight | 4694 of 14129 | | Warranty | 9912 of 14129 | ## Pros - **BNEF Tier-1 status for 9 consecutive years** - Phono Solar has held BloombergNEF Tier-1 status continuously since 2014, including Q2 and Q3 2023, confirming financial stability and easing project debt financing for installations built on this series. - **Half-cut cell design reduces hotspot risk** - Splitting cells in half lowers resistive losses and the risk of local overheating, giving the module more stable output under partial shading (e.g., from a chimney or dormer) compared to full-cell designs. - **PID resistance and high-seal junction box** - Certified resistance to potential-induced degradation (PID) combined with a high-seal junction box supports long-term reliability in both roof-mounted and ground-mount installations, reducing the risk of moisture-related failures. - **Efficiency competitive with the premium segment** - Peak efficiency of 21.3% sits near the top of the segment - above JA Solar's JAM60S21 (21.0%) and on par with Meyer Burger Glass (21.2%), though slightly below LG NeON R Prime (21.5%). - **Standard 25-year power warranty** - The linear power warranty covers 25 years, matching the industry standard for PERC modules from this production era (2020-2023) and in line with terms offered by comparable Tier-1 manufacturers. ## Cons - **Production discontinued in 2023** - The Twinplus M4-9B-R series has been discontinued (production end: 2023), meaning limited availability of replacement modules for expanding existing arrays and potentially harder-to-secure warranty service over the long term. - **Older-generation PERC technology** - Unlike some comparable premium models (e.g., LG NeON R Prime on N-type cells, Meyer Burger Glass on HJT), this series uses P-type Mono-PERC cells, which typically show higher LID/LeTID degradation rates than newer N-type technologies. - **Shorter product warranty than some competitors** - The 12-year product warranty was standard for its market era, but is notably shorter than the 20-25 year product warranties now offered by some premium manufacturers, which can matter when comparing total cost of ownership (TCO). ## About this series The Phono Solar Twinplus Module Series (HIGH EFFICIENCY MONO-PERC M4-9B-R) is designed to maximize energy output from the same roof surface. The use of **monocrystalline Mono-PERC cells** helps better utilize reflected light within the cell structure, translating to more stable performance under the variable conditions typical of Polish weather. A key feature is the **half-cut design**, which minimizes connection losses and reduces the risk of local overheating, ensuring reliable operation even under partial shading (e.g., from a chimney or window frame). In practice, the Twinplus M4-9B-R solves the problem of "space constraints" - it enables stronger installations on smaller roof pitches without compromising on quality. Additionally, **PID resistance** and the refined **high-seal junction box** support long-term reliability in both roof-mounted and ground installations. This is an excellent choice for single-family homes, businesses, and projects where yield, durability, and predictable system performance over years are key factors. ## Notable figures - 21.3% module efficiency - 1.9pp better than the \*\*PERC 0-400W\*\* median of 19.4% - At 213.0 W/m² power density, this panel generates 18.8 W/m² more per unit area than \*\*PERC 0-400W\*\* median (194.2 W/m²) - At -0.34%/°C, hot weather performance is typical for \*\*PERC 0-400W\*\* panels - In the top 61% for efficiency among all PERC panels ## Questions ### Is the Phono Solar Twinplus M4-9B-R series still available for purchase? The Phono Solar Twinplus Module Series HIGH EFFICIENCY MONO-PERC M4-9B-R has been discontinued and is no longer offered as a new product through official distributors. If you need a replacement, consider newer Phono Solar series based on M10 or larger cell formats, which deliver higher wattage per module while retaining comparable PERC half-cut technology. ### What warranties come with the Phono Solar Twinplus M4-9B-R panels? The manufacturer provided a 12-year product warranty covering material and workmanship defects, plus a 25-year linear power output warranty. In practice, after 25 years the panel should retain at least 80-83% of its nominal 390 W output. Both warranties apply when the system is installed by a certified installer and operated according to the manual. ### What does half-cut mean in the Twinplus M4-9B-R and does it help with shading? Half-cut technology splits each PERC cell in half, reducing resistive losses and minimizing hot-spot risk. The Twinplus M4-9B-R uses 144 half-cut cells instead of the standard 72. When partial shading occurs - for example from a chimney or satellite dish - the module loses proportionally less power than a conventional full-cell panel. ### How heavy is the Phono Solar Twinplus M4-9B-R and will it fit on a standard roof? The panel weighs approximately 22.6 kg with dimensions of about 2000 × 992 × 40 mm. This is a standard format for 144-cell modules that is compatible with typical roof mounting systems. Each panel covers just under 2 m², meaning roughly 5.5-6 kW of capacity fits on a 30 m² roof section. ### How does the Twinplus M4-9B-R perform in winter and overcast conditions? Mono-PERC technology provides better low-light and diffuse-irradiance response compared to polycrystalline cells, which is an advantage in the frequently overcast Polish climate. The power temperature coefficient is approximately -0.37%/°C, meaning on cold, sunny winter days the panel can exceed its nominal output. PID resistance further protects the module under high humidity and dew conditions. ### Are Phono Solar Twinplus M4-9B-R panels suitable for ground-mount installations? Yes, the Twinplus M4-9B-R series was designed for both rooftop and ground-mount applications. The high-IP-rated junction box provides reliable protection against moisture and dust, which is especially important in ground-level installations. Standard module dimensions are compatible with most racking systems available on the market. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/28230555765716d82916d1-ba52decc10c0.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 | +50 W, cooler, +1.8 pp | | [Gamko New Energy GKA210M340W](https://comparepv.com/panel/gamko-new-energy-gka210m340w) | 340 W | -50 W, +1.7 pp, +5 yr warranty | | [Gamko New Energy GKA210M360W](https://comparepv.com/panel/gamko-new-energy-gka210m360w) | 360 W | Lighter, +1.7 pp, +5 yr warranty | | [Gamko New Energy GKA210M380W (1/4\*4\*38)](https://comparepv.com/panel/gamko-new-energy-gka210m380w-1-4-4-38) | 380 W | Lighter, +1.7 pp, +5 yr warranty | | [Gamko New Energy GKA210M400W (1/2\*4\*20)](https://comparepv.com/panel/gamko-new-energy-gka210m400w-1-2-4-20) | 400 W | Lighter, +1.7 pp, +5 yr warranty | | [Gamko New Energy GKA210M400W (1/4\*4\*40)](https://comparepv.com/panel/gamko-new-energy-gka210m400w-1-4-4-40) | 400 W | Lighter, +1.7 pp, +5 yr warranty | | [Gamko New Energy GKA210M380W (1/2\*4\*19)](https://comparepv.com/panel/gamko-new-energy-gka210m380w-1-2-4-19) | 380 W | Lighter, +1.7 pp, +5 yr warranty | | [Jetion JT440SYK(B)](https://comparepv.com/panel/jetion-jt440syk-b) | 440 W | +50 W, cooler, +1.6 pp | | [Phono Solar PS370M4-20/UH](https://comparepv.com/panel/phono-solar-technology-co-ltd-ps370m4-20-uh) | 370 W | -20 W, -1.1 pp | | [Phono Solar PS375M4-20/UH](https://comparepv.com/panel/phono-solar-technology-co-ltd-ps375m4-20-uh) | 375 W | -15 W, -0.8 pp | | [Phono Solar PS380M4-20/UH](https://comparepv.com/panel/phono-solar-technology-co-ltd-ps380m4-20-uh) | 380 W | -10 W, -0.5 pp | | [Phono Solar PS385M4-20/UH](https://comparepv.com/panel/phono-solar-technology-co-ltd-ps385m4-20-uh) | 385 W | -0.3 pp | | [Longi Solar LR7-54HJD-510M](https://comparepv.com/panel/longi-lr7-54hjd-510m) | 510 W | +120 W, cooler, +3.7 pp | | [AIKO AIKO-A495-MCE54Mw](https://comparepv.com/panel/aiko-aiko-a495-mce54mw) | 495 W | +105 W, cooler, +3.5 pp | | [Longi Solar LR7-54HJD-505M](https://comparepv.com/panel/longi-lr7-54hjd-505m) | 505 W | +115 W, cooler, +3.4 pp | | [WINAICO WST-505BKX54-A2](https://comparepv.com/panel/winaico-wst-505bkx54-a2) | 505 W | +115 W, cooler, +3.4 pp | --- Source: https://comparepv.com/panel/phono-solar-technology-co-ltd-ps390m4-20-uh 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.