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Resun Solar RS9K645M
Resun Solar Brand review

RS9K645M

645 Wp Monocrystalline
ComparePV verdict

Light for its output, no clear weak spot

Rank 1,678 of 14,005
Compare panels Datasheet PDF
Power (Wp)
645
Typical for its class
Efficiency (%)
22.79
Typical · median 22.45%
Density (Wp/m²)
227.9
Typical · median 224.5
Temp (%/°C)
-0.300
Typical · median -0.290
Weight (kg)
30.9
Strong · 1.6 kg below median
Warranty (yrs)
30
Typical · median 30 yrs

The RS9K-M series from Resun Solar comprises monocrystalline 615-645W half-cell modules built with 18 busbars, engineered to maximize energy yield while minimizing internal losses. The multi-busbar technology distributes current more evenly across the cells, reducing the risk of failures caused by microcracks and broken busbars and extending the practical service life of the installation. Thanks to the half-cut cell design, the module offers strong resistance to hot-spot effects triggered by partial shading, making it a solid choice for installations exposed to uneven sunlight, such as near trees or chimneys. The panel also stands out for its PID resistance, which limits power degradation over time and contributes to a lower LCOE for the whole system. A 3.2 mm tempered glass with anti-reflective coating delivers better performance in low-light conditions, a relevant advantage under Poland's often overcast climate. Certified to withstand wind loads of 2400 Pa and snow loads of 5400 Pa, the construction is resistant to demanding mechanical conditions, including salt mist and ammonia exposure, making it suitable for roofs on farms and industrial buildings. The series is aimed at investors seeking a balance between performance, durability, and predictable operating costs.

Ranking

5,677 panels in the 545-745 W band, all technologies
Metric This panel Median Position in segment Overall rank
Module efficiency 22.79% 22.45% Typical 3,005
Power density 227.9 224.5 Typical 2,773
Temperature coefficient -0.300 -0.290 Typical 6,093
Weight per kWp 47.9 53.0 Strong · top 13% 1,967
Performance warranty 30 yrs 30 yrs Typical 21
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Signals from the data

1 positive · 0 caution
Best for

Commercial, utility-scale and shaded-installations.

Strengths
47.9 kg per kWp

Top 13% of the 545-745 W band, against a median of 53.0.

Notes from the database
  • Efficiency of 22.8% is 1.0pp above the database median (21.8%)
  • At 227.9 W/m² power density, this panel generates 9.8 W/m² more per unit area than database median (218.1 W/m²)
  • Temperature coefficient of -0.30%/°C matches the database median
  • At 30.9 kg, this panel is 4.4 kg heavier than the database median (26.5 kg) - more demanding for installation crews
  • Ranked #3005 out of 14005 panels for efficiency in the database

Specifications

Open datasheet PDF
Nominal power (Pmax) 645 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 22.79 % Typical Segment median 22.45%
Vmpp · Impp 37.20 V · 17.34 A Operating point at max power
Voc · Isc 44.80 V · 18.33 A Sizes the string length
Max system voltage 1500 V Longer strings than 1000 V modules
Dimensions 2172×1303×35 mm · 2.83 m² of roof
Weight 30.9 kg Strong Strong · 1.6 kg below median
Cells 120 Monocrystalline
Coefficient Pmax -0.300 %/°C Typical median -0.290 of its segment
Coefficient Voc · Isc -0.250 · 0.045 %/°C
NOCT 45 °C At 800 W/m², 20 °C ambient
Product warranty 15 years Hardware defects only
Performance warranty 30 years Typical median 30 yrs · median 30 yrs
Degradation 0.50 % Per year after the first

Datasheet charts

Open datasheet PDF

Measured curves published by Resun Solar in this model's datasheet. A chart carrying a wattage was measured on that variant alone - only the ones that describe 645 Wp appear here. The rest cover the whole series.

0.5% Annual Degradation over 30 years 0.5% Annual Degradation over 30 years Whole series I-V Curves of PV Module(645W) I-V Curves of PV Module(645W) 645 W P-V Curves of PV Module(645W) P-V Curves of PV Module(645W) 645 W

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
-0.300 %/°C against a segment median of -0.290
-

Alternatives

All Resun Solar panels
Filter these
Size
Panel Power Eff. Temp. Weight Difference
Resun Solar RS9K645M 645 W 22.79% -0.300 30.9 kg You are here
AIKO-A650-MAE72Mw 650 W 25.20% -0.260 27.0 kg Cooler, lighter, +2.4 pp
AIKO-A680-MDE72Mw 680 W 25.20% -0.260 29.0 kg +35 W, cooler, +2.4 pp
AIKO-A675-MDE72Mw 675 W 25.00% -0.260 29.0 kg +30 W, cooler, +2.2 pp
AIKO-A645-MAE72Mw 645 W 25.00% -0.260 27.0 kg Cooler, lighter, +2.2 pp
AIKO-A695-MAE78Dw 695 W 24.90% -0.260 34.5 kg +50 W, cooler, +2.1 pp
AIKO-G670-MCH72Mw 670 W 24.80% -0.260 28.2 kg Cooler, lighter, +2.0 pp
LR7-72HVHF-670M 670 W 24.80% -0.260 28.5 kg +25 W, cooler, +2.0 pp
RS9K-M-DG-610 610 W 21.55% -0.300 34.5 kg -35 W, heavier, -1.2 pp
RS9K-M-DG-615 615 W 21.73% -0.300 34.5 kg -30 W, heavier, -1.1 pp
RS9K-M-DG-620 620 W 21.91% -0.300 34.5 kg -25 W, heavier, -0.9 pp
RS9K-M-DG-625 625 W 22.08% -0.300 34.5 kg -20 W, heavier, -0.7 pp
RS9K-M-DG-630 630 W 22.26% -0.300 34.5 kg -15 W, heavier, -0.5 pp
RS9K-M-DG-635 635 W 22.44% -0.300 34.5 kg -10 W, heavier, -0.3 pp
GKA210N120 680 W 24.03% -0.340 28.0 kg +35 W, hotter, +1.2 pp
GKA210N120-675 675 W 23.85% -0.340 28.0 kg +30 W, hotter, +1.1 pp
QN-670HJT-01 670 W 23.70% -0.240 35.5 kg Cooler, heavier, +0.9 pp

Found 497 panels of the same or similar size to this one, within ±10 mm. See them here Found 502 panels of the same or similar size to this one, within ±25 mm. See them here Found 502 panels of the same or similar size to this one, within ±50 mm. See them here Found 506 panels of the same or similar size to this one, within ±100 mm. See them here

Common questions

6 answered
What is the maximum power output of the Resun Solar RS9K-M series panel?
RS9K-M series panels reach up to 645 Wp. Built with monocrystalline half-cut cells and 18 busbars, these high-power modules are well suited for installations with limited roof space where maximizing energy yield per panel matters.
What warranty comes with Resun Solar RS9K-M panels?
The manufacturer provides a 15-year product warranty and a 30-year power output warranty. This covers both material and workmanship defects as well as gradual power degradation over time, giving a predictable operating cost for the entire lifespan of the installation.
Are RS9K-M panels bifacial?
No, the RS9K-M series consists of mono-facial panels. Energy is generated solely from the front side of the module. If you need extra yield from reflected light, for example on a light-colored roof or ground-mount system, consider a bifacial series from Resun Solar instead.
Are RS9K-M panels suitable for farm buildings or industrial roofs?
Yes, the frame is certified for wind loads up to 2400 Pa and snow loads up to 5400 Pa, and it also resists salt mist and ammonia corrosion. This makes the panels well suited to the demanding mechanical and chemical conditions typical of livestock buildings and industrial facilities.
How does the half-cut, 18-busbar technology in RS9K-M differ from standard panels?
Splitting cells into halves reduces current losses and improves resistance to hot-spot effects caused by partial shading, such as from trees or chimneys. The 18 busbars distribute current more evenly across the cells, lowering the risk of failures from microcracks and extending the system's real-world lifespan.
Do RS9K-M panels perform well in low-light conditions typical of a temperate climate?
Yes, the 3.2 mm tempered glass with anti-reflective coating improves performance under low irradiance, which matters in climates with many overcast days. Combined with PID resistance limiting power degradation over time, this contributes to a lower LCOE for the installation.
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