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Phono Solar PS370M4-20/UH
Phono Solar Brand review

PS370M4-20/UH

370 Wp PERC
ComparePV verdict

Strong in heat, no clear weak spot

Rank 12,603 of 14,129
Compare panels Datasheet PDF
Power (Wp)
370
Typical for its class
Efficiency (%)
20.21
Typical · median 19.90%
Density (Wp/m²)
202.1
Typical · median 199.0
Temp (%/°C)
-0.340
Strong · top 15%
Weight (kg)
20.0
Typical · median 21.4 kg
Warranty (yrs)
25
Typical · median 25 yrs

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.

Ranking

579 panels in the segment PERC 350-400 W
Metric This panel Median Position in segment Overall rank
Module efficiency 20.21% 19.90% Typical 12,028
Power density 202.1 199.0 Typical 12,069
Temperature coefficient -0.340 -0.350 Strong · top 15% 8,846
Weight per kWp 54.1 55.8 Typical 8,346
Performance warranty 25 yrs 25 yrs Typical 9,912
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Signals from the data

6 positive · 3 caution
Best for

Residential, commercial and shaded-installations.

Strengths
-0.340 %/°C temperature coefficient

Top 15% of the PERC 350-400 W segment, against a median of -0.350.

What owners get
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.

Trade-offs
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).

Notes from the database
  • 20.2% module efficiency - 0.8pp better than the PERC 0-400W median of 19.4%
  • At 202.1 W/m² power density, this panel generates 7.9 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
  • Ranked #12028 out of 14129 panels for efficiency in the database

Specifications

Open datasheet PDF
Nominal power (Pmax) 370 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 20.21 % Typical Segment median 19.90%
Vmpp · Impp 34.20 V · 10.82 A Operating point at max power
Voc · Isc 40.97 V · 11.31 A Sizes the string length
Max system voltage 1500 V Longer strings than 1000 V modules
Dimensions 1762×1039×30 mm · 1.83 m² of roof
Weight 20.0 kg Typical Typical · median 21.4 kg
Cells 120 · PERC Monocrystalline
Coefficient Pmax -0.340 %/°C Strong top 15% of its segment
Coefficient Voc · Isc -0.270 · 0.045 %/°C
NOCT 45 °C At 800 W/m², 20 °C ambient
Product warranty 12 years Hardware defects only
Performance warranty 25 years Typical median 25 yrs · median 25 yrs
End-of-warranty output 84.8 % Equals 304 W guaranteed
Degradation 2.00 → 0.55 % First year, then annual

Datasheet charts

Open datasheet PDF

Measured curves published by Phono Solar in this model's datasheet. A chart carrying a wattage was measured on that variant alone - only the ones that describe 370 Wp appear here. The rest cover the whole series.

Guaranteed Power vs. Year – 25-year Linear Performance Warranty Guaranteed Power vs. Year – 25-year Linear Performance Warranty Whole series Power-Voltage (P-V) Curves at Varying Irradiance, Cell temp.=25°C Power-Voltage (P-V) Curves at Varying Irradiance, Cell temp.=25°C Whole series Current-Voltage (I-V) Curves at Varying Irradiance, Cell temp.=25°C Current-Voltage (I-V) Curves at Varying Irradiance, Cell temp.=25°C Whole series

Simulations

Live - change any input
Lifetime output & value
30 years at 1200 kWh/kWp/year and €0.50 per kWh
Power in year 30
-
Lifetime energy
-
Energy value
-

Degradation from this panel's own datasheet figures. No inverter, soiling or shading losses.

Heat losses
-0.340 %/°C against a segment median of -0.350
-
Filter these
Size
Panel Power Eff. Temp. Weight Difference
Phono Solar PS370M4-20/UH 370 W 20.21% -0.340 20.0 kg You are here
NS-330MH-80 330 W 23.15% -0.290 15.0 kg Cooler, lighter, +2.9 pp
NS-330MH-80 330 W 23.15% -0.290 15.0 kg Cooler, lighter, +2.9 pp
GKA210M320W 320 W 23.00% - 16.2 kg -50 W, +2.8 pp, +5 yr warranty
GKA210M340W 340 W 23.00% - 16.2 kg Lighter, +2.8 pp, +5 yr warranty
GKA210M360W 360 W 23.00% - 16.2 kg Lighter, +2.8 pp, +5 yr warranty
GKA210M380W (1/4*4*38) 380 W 23.00% - 17.1 kg Lighter, +2.8 pp, +5 yr warranty
GKA210M400W (1/2*4*20) 400 W 23.00% - 18.0 kg +30 W, +2.8 pp, +5 yr warranty
GKA210M400W (1/4*4*40) 400 W 23.00% - 18.0 kg +30 W, +2.8 pp, +5 yr warranty
GKA210M380W (1/2*4*19) 380 W 23.00% - 17.1 kg Lighter, +2.8 pp, +5 yr warranty
SPR-MAX3-400-COM 400 W 22.60% -0.270 19.0 kg Cooler, +2.4 pp, +15 yr warranty
PS375M4-20/UH 375 W 20.48% -0.340 20.0 kg +0.3 pp
PS380M4-20/UH 380 W 20.76% -0.340 20.0 kg +10 W, +0.6 pp
PS385M4-20/UH 385 W 21.03% -0.340 20.0 kg +15 W, +0.8 pp
PS390M4-20/UH 390 W 21.30% -0.340 20.0 kg +20 W, +1.1 pp
LR7-54HJD-510M 510 W 25.00% -0.240 23.5 kg +140 W, cooler, +4.8 pp
AIKO-A495-MCE54Mw 495 W 24.80% -0.260 21.0 kg +125 W, cooler, +4.6 pp

Found 234 panels of the same or similar size to this one, within ±10 mm. See them here Found 272 panels of the same or similar size to this one, within ±25 mm. See them here Found 319 panels of the same or similar size to this one, within ±50 mm. See them here Found 4182 panels of the same or similar size to this one, within ±100 mm. See them here

About the Twinplus Module Series (HIGH EFFICIENCY MONO-PERC M4-9B-R) series

6 answered

These answers cover the whole series. Where a figure differs, the specification above is this module's own.

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.
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