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JS Solar Brand review

JS305M

305 Wp PERC
ComparePV verdict

Middle of its segment, weak in heat

Rank 13,264 of 14,005
Compare panels Datasheet PDF
Power (Wp)
305
Weak · bottom 9%
Efficiency (%)
18.75
Typical · median 19.00%
Density (Wp/m²)
187.5
Typical · median 190.0
Temp (%/°C)
-0.420
Weak · bottom 7%
Weight (kg)
18.0
Typical · median 19.0 kg
Warranty (yrs)
25
Typical · median 25 yrs

The JS Solar 60+ SERIES represents an advanced response to the growing market demand for maximizing yields from limited roof space. The use of N-Type TOPCon cell technology allows these modules to achieve significantly higher conversion efficiency and better performance in low-light conditions, which is crucial in the Polish climate zone. These panels eliminate the problem of rapid power degradation, offering investors exceptional resistance to LID and LeTID effects, which translates into financial stability and predictability of energy production over several decades. Thanks to the use of larger silicon wafers and innovative busbar layout, the 60+ SERIES minimizes resistance losses, which distinguishes it from standard competitor solutions. It is the optimal choice for demanding prosumers and companies that care about a low temperature coefficient, guaranteeing high production even during hot summer days. The module construction provides excellent mechanical strength, protecting the installation against extreme weather events. By choosing the 60+ series, the user invests in energy security and faster return on investment, receiving a product that combines solid workmanship with the latest achievements in photovoltaic engineering currently available on the market.

Ranking

286 panels in the segment PERC 300-350 W
Metric This panel Median Position in segment Overall rank
Module efficiency 18.75% 19.00% Typical 13,047
Power density 187.5 190.0 Typical 13,026
Temperature coefficient -0.420 -0.360 Weak · bottom 7% 13,796
Weight per kWp 59.0 60.0 Typical 11,981
Performance warranty 25 yrs 25 yrs Typical 9,798
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Signals from the data

4 positive · 5 caution
Not ideal for

Hot climates.

Watch-outs
-0.420 %/°C temperature coefficient

Bottom 7% of the PERC 300-350 W segment, against a median of -0.360. Ranked 13,796th in the whole database.

What owners get
Up to 19.67% efficiency – top of PERC segment

Maximum efficiency of 19.67% matches the best peer in the comparison group (SP Enerji Solar Power 300–320 W, 19.67%) and exceeds both Sun Earth AGRI and Sunket 182mm (19.55% each). Within the 60-cell PERC 305–320 Wp class, this places the series in the top decile of the market.

Four power variants – flexible sizing

The series spans four power variants from 305 to 320 Wp, enabling precise array sizing for constrained roof areas without switching to a different series or manufacturer.

Full safety certification set

Modules carry IEC 61215, IEC 61730, CE, PID Resistance, Salt Mist, and Ammonia Corrosion certifications — the baseline required for bankable project due diligence and by most insurers operating in European markets.

25-year linear power warranty

A 25-year performance warranty aligns with the market standard for PERC modules. The gap to premium-tier leaders (e.g., REC Alpha, Panasonic EverVolt — 25–30 years) is 0–5 years, which does not disqualify the series for typical residential or C&I installations.

Trade-offs
PERC, not N-type TOPCon – conflicts with marketing copy

The technical specifications list PERC (P-type) cell technology, not the N-type TOPCon promoted in the product description. PERC cells exhibit LID degradation of 0.5–1% in the first year and a weaker temperature coefficient (~-0.37%/°C vs. TOPCon's -0.30%/°C), resulting in approximately 1.5–2.5% lower annual energy yield compared to a TOPCon module at the same nameplate power.

Monofacial only – bifacial peers available

The series is monofacial (is_bifacial: false), while direct peer Sunket 182mm 80Cells offers a bifacial double-glass module at the same 320 Wp and near-identical 19.55% efficiency. In ground-mount or light-colored rooftop installations, bifacial modules typically deliver 10–20% additional annual yield.

10-year product warranty – market minimum

The product warranty is 10 years, whereas BNEF Tier-1 manufacturers (JA Solar, JinkoSolar, Trina Solar) standardly offer 12–15 years. The gap is negligible within the typical 7–9 year payback period, but any failure in years 11–15 falls outside warranty coverage.

Manufacturer absent from BNEF Tier-1 list (Q1 2026)

JS Solar (Yixing JS Solar Co., Ltd.) does not appear on the BloombergNEF Tier-1 PV Module Manufacturers list for Q1 2026. Non-bankable status restricts debt financing for commercial-scale projects and may reduce the residual value of a system at property sale.

Notes from the database
  • At 18.8% efficiency, this panel is 0.7pp below the PERC 0-400W median of 19.4%
  • Power density of 187.5 W/m² is 6.9 W/m² below PERC 0-400W median (194.4 W/m²) - needs more roof space
  • At -0.42%/°C, loses 0.06pp more power per degree than PERC 0-400W median (-0.36%/°C)
  • 18.0 kg weight - 2.5 kg lighter than PERC 0-400W median (20.5 kg), reducing installation effort
  • #13047 for efficiency, #13796 for temperature performance out of 14005 panels

Specifications

Open datasheet PDF
Nominal power (Pmax) 305 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 18.75 % Typical Segment median 19.00%
Vmpp · Impp 32.97 V · 9.25 A Operating point at max power
Voc · Isc 39.05 V · 9.50 A Sizes the string length
Max system voltage 1000 V Longer strings than 1000 V modules
Dimensions 1640×992×35 mm · 1.63 m² of roof
Weight 18.0 kg Typical Typical · median 19.0 kg
Cells 60 · PERC Monocrystalline
Coefficient Pmax -0.420 %/°C Weak bottom 7% of its segment
Coefficient Voc · Isc -0.320 · 0.060 %/°C
NOCT 45 °C At 800 W/m², 20 °C ambient
Product warranty 10 years Hardware defects only
Performance warranty 25 years Typical median 25 yrs · median 25 yrs
End-of-warranty output 80.2 % Equals 234 W guaranteed
Degradation 3.00 → 0.70 % First year, then annual

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
-0.420 %/°C against a segment median of -0.360
-

Alternatives

All JS Solar panels
Filter these
Size
Panel Power Eff. Temp. Weight Difference
JS Solar JS305M 305 W 18.75% -0.420 18.0 kg You are here
NS-300MH-72 300 W 23.32% -0.290 12.5 kg Cooler, lighter, +4.6 pp
NS-300MH-72 300 W 23.32% -0.290 12.5 kg Cooler, lighter, +4.6 pp
ZEUS 1.2 FullBlack 280W 280 W 23.31% -0.260 14.3 kg Cooler, +4.6 pp, +5 yr warranty
NS-330MH-80 330 W 23.15% -0.290 15.0 kg Cooler, lighter, +4.4 pp
NS-330MH-80 330 W 23.15% -0.290 15.0 kg Cooler, lighter, +4.4 pp
GKA182M285W 285 W 23.00% - 10.8 kg Lighter, +4.2 pp, +5 yr warranty
GKA182M260W 260 W 23.00% - 10.8 kg Lighter, +4.2 pp, +5 yr warranty
GKA182M270W 270 W 23.00% - 10.8 kg Lighter, +4.2 pp, +5 yr warranty
GKA182M300W 300 W 23.00% - 16.2 kg Lighter, +4.2 pp, +5 yr warranty
JS260P 260 W 15.90% -0.420 19.3 kg -45 W, heavier, -2.8 pp
JS265P 265 W 16.20% -0.420 19.3 kg -40 W, heavier, -2.6 pp
JS270P 270 W 16.50% -0.420 19.3 kg -35 W, heavier, -2.2 pp
JS275P 275 W 16.80% -0.420 19.3 kg -30 W, heavier, -1.9 pp
JS280P 280 W 17.20% -0.420 19.3 kg -25 W, heavier, -1.6 pp
JS310M 310 W 19.05% -0.420 18.0 kg +0.3 pp
JS315M 315 W 19.36% -0.420 18.0 kg +10 W, +0.6 pp
SPR-MAX3-400-COM 400 W 22.60% -0.270 19.0 kg Cooler, +3.9 pp, +15 yr warranty

Found 182 panels of the same or similar size to this one, within ±10 mm. See them here Found 218 panels of the same or similar size to this one, within ±25 mm. See them here Found 379 panels of the same or similar size to this one, within ±50 mm. See them here Found 472 panels of the same or similar size to this one, within ±100 mm. See them here

Common questions

6 answered
What warranty does the JS Solar 60+ SERIES come with, and what does it cover?
The JS Solar 60+ SERIES includes a 10-year product warranty covering material and workmanship defects, plus a 25-year linear power warranty guaranteeing at least 80.2% of nominal output after 25 years. This is a solid standard for this price range, though leading Tier 1 manufacturers sometimes offer 30-year power warranties. It is worth discussing warranty service terms with the local distributor before purchasing.
What is PERC technology and why does the JS Solar 60+ SERIES use it?
PERC (Passivated Emitter Rear Contact) adds a passivation layer on the rear side of the silicon wafer, reflecting photons that would otherwise be lost back into the cell junction. In the 60+ SERIES, this enables module efficiency of up to 19.67%, well above older BSF cells. It is a cost-effective choice at this price point, though newer N-Type TOPCon and HJT technologies offer higher efficiency and a better temperature coefficient.
Is the JS Solar 60+ SERIES 320 Wp panel suitable for a pitched roof in Poland?
Yes, the JS156M60-320W module measures 1640×992 mm and weighs approximately 18 kg, making it well-suited for standard Polish pitched roofs with tilt angles of 15–45°. The lightweight build simplifies crew installation. The panel uses PERC cell technology with a temperature coefficient of -0.42%/°C — a typical and acceptable figure for Polish climate conditions.
Is the JS Solar 60+ SERIES a bifacial panel?
No, the 60+ SERIES is a monofacial panel — power is generated only through the front glass side of the module. Bifacial panels can produce an additional 5–15% energy from reflected irradiance, but require a light-colored ground surface and adequate mounting height. On standard pitched roofs, the real-world annual yield difference is typically minimal, and monofacial panels remain a simpler and more affordable option.
Is JS Solar a reliable manufacturer? What does the lack of Tier 1 status mean?
JS Solar (Yixing JS Solar Co., Ltd.) is a Chinese manufacturer with several years on the market. The absence of Tier 1 status — assigned by BloombergNEF — primarily means the company has not yet secured financing for projects through major investment banks; it is not a direct indicator of product quality. Before buying, verify IEC 61215 and IEC 61730 certifications, check references from local installers in Poland, and confirm warranty service terms with the regional distributor.
How does the JS Solar 60+ SERIES perform during hot summer days and what is the impact on energy output?
The power temperature coefficient for the 60+ SERIES is -0.42%/°C, meaning the panel loses 0.42% of its rated power for each degree Celsius above 25°C (STC). At a module temperature of 65°C on a hot summer day, real-world output drops by approximately 16.8%. This is a typical result for PERC technology. N-Type TOPCon or HJT modules offer better coefficients in the range of -0.30 to -0.26%/°C, but are generally priced higher.
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