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Renesola RS9-660M-E1
Renesola Brand review

RS9-660M-E1

660 Wp N-type
ComparePV verdict

Middle of its segment, modest efficiency

Rank 4,111 of 14,005
Compare panels Datasheet PDF
Power (Wp)
660
Typical for its class
Efficiency (%)
21.25
Weak · bottom 7%
Density (Wp/m²)
212.5
Weak · bottom 7%
Temp (%/°C)
-0.340
Weak · bottom 10%
Weight (kg)
33.5
Typical · median 33.5 kg
Warranty (yrs)
25
Weak · bottom 7%

The Renesola RS9-650~670M-E1 series is designed for installations where maximizing power output per square meter and stable performance in varying weather conditions are crucial. The modules utilize MBB half-cut technology, which helps minimize losses in connections and improves performance under partial shading - a key factor for roofs of warehouses, agricultural buildings, and other structures. The use of galem-doped wafers supports long-term parameter stability, while non-destructive cutting reduces the risk of micro-cracks that can reduce energy production after several seasons. A key feature of this series is its excellent performance in low light and under unfavorable angles of incidence, which translates to better results in the morning, evening, and winter. The RS9-650~670M-E1 is a suitable choice for PV farms and commercial projects where predictability, durability, and efficient use of structures and cabling are essential.

Ranking

109 panels in the segment N-type 650-700 W
Metric This panel Median Position in segment Overall rank
Module efficiency 21.25% 23.30% Weak · bottom 7% 8,904
Power density 212.5 233.2 Weak · bottom 7% 8,959
Temperature coefficient -0.340 -0.290 Weak · bottom 10% 8,778
Weight per kWp 50.8 50.9 Typical 4,172
Performance warranty 25 yrs 30 yrs Weak · bottom 7% 9,798
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Signals from the data

5 positive · 6 caution
Best for

Commercial, utility-scale and shaded-installations.

Not ideal for

Tight roof space, roofs where every square metre has to count and owners who want a long output guarantee.

Watch-outs
21.25% module efficiency

Bottom 7% of the N-type 650-700 W segment, against a median of 23.30%. Ranked 8,904th in the whole database.

212.5 watts per square metre

Bottom 7% of the N-type 650-700 W segment, against a median of 233.2. Ranked 8,959th in the whole database.

25 year performance warranty

Bottom 7% of the N-type 650-700 W segment, against a median of 30 yrs. Ranked 9,798th in the whole database.

What owners get
Latest-generation N-type cells

N-type technology instead of older PERC results in lower LID/LeTID degradation and a better power temperature coefficient, translating into higher annual energy yield, especially in hot climates.

MBB half-cut with non-destructive cutting

The combination of multi-busbar half-cut cells with non-destructive wafer cutting reduces resistive losses at interconnections and lowers the risk of microcracks, which after several seasons of operation can cut energy output by several percent.

Gallium-doped wafers

Gallium doping instead of standard boron improves the long-term stability of the module's electrical parameters, reducing light-induced degradation (LID) in the first years of operation.

Tier-1 manufacturer with 20 years on the market

Renesola is a Tier-1 (bankable) manufacturer operating since 2005, increasing financing security for PV farms and commercial projects backed by banks and investment funds.

Efficiency at the top of the segment

Efficiency up to 21.57% puts the RS9-650~670M-E1 series virtually on par with Techwise Solar Summit Series (21.57%) and Resun RS9H-M (21.57%), only marginally behind Hiwatt HW-M12/132H (21.6%).

Trade-offs
Warranty below current market standard

A 12-year product warranty and 25-year power warranty (84.8% end-of-term) lag behind the increasingly common 2026 Tier-1 offerings of 15-year product and 30-year linear power warranties, which can affect the residual value assessment of the installation.

No bifacial variant in this line

The RS9-650~670M-E1 series is monofacial (is_bifacial: false), while Renesola offers a parallel bifacial variant (RS9-660MBG-E1) at similar power - for ground-mount or elevated installations, the lack of a bifacial option means forgoing a potential additional 5-10% yield.

Marginally lower efficiency than segment leader

Maximum efficiency of 21.57% is slightly below Hiwatt Solar HW-M12/132H (21.6%) - the difference is minimal, but on large PV farms even 0.03 pp translates into a real difference in total installed power on the same roof area.

Notes from the database
  • Efficiency of 21.2% is 2.1pp below the N-type 650-700W median (23.3%)
  • 212.5 W/m² power density is 20.7 W/m² below N-type 650-700W median (233.2 W/m²) - requires larger installation area
  • Temperature coefficient of -0.34%/°C is 0.05pp worse than N-type 650-700W median (-0.29%/°C) - higher losses in summer heat
  • Ranked #8904 out of 14005 panels for efficiency in the database

Specifications

Open datasheet PDF
Nominal power (Pmax) 660 Wp Nameplate at 1000 W/m², 25 °C
Module efficiency 21.25 % Weak Segment median 23.30%
Vmpp · Impp 37.80 V · 17.47 A Operating point at max power
Voc · Isc 45.70 V · 18.53 A Sizes the string length
Max system voltage 1500 V Longer strings than 1000 V modules
Dimensions 2384×1303×33 mm · 3.11 m² of roof
Weight 33.5 kg Typical Typical · median 33.5 kg
Cells 132 · N-type Monocrystalline
Coefficient Pmax -0.340 %/°C Weak bottom 10% of its segment
Coefficient Voc · Isc -0.250 · 0.040 %/°C
NOCT 43 °C At 800 W/m², 20 °C ambient
Product warranty 12 years Hardware defects only
Performance warranty 25 years Weak bottom 7% · median 30 yrs
End-of-warranty output 84.8 % Equals 542 W guaranteed
Degradation 2.00 → 0.55 % 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
-0.340 %/°C against a segment median of -0.290
-
Filter these
Size
Panel Power Eff. Temp. Weight Difference
Renesola RS9-660M-E1 660 W 21.25% -0.340 33.5 kg You are here
AIKO-A650-MAE72Mw 650 W 25.20% -0.260 27.0 kg Cooler, lighter, +3.9 pp
AIKO-A680-MDE72Mw 680 W 25.20% -0.260 29.0 kg Cooler, +3.9 pp, +5 yr warranty
AIKO-A675-MDE72Mw 675 W 25.00% -0.260 29.0 kg Cooler, +3.8 pp, +5 yr warranty
AIKO-A645-MAE72Mw 645 W 25.00% -0.260 27.0 kg Cooler, lighter, +3.8 pp
AIKO-A700-MAE78Dw 700 W 25.00% -0.260 34.5 kg Cooler, +3.8 pp, +5 yr warranty
AIKO-A695-MAE78Dw 695 W 24.90% -0.260 34.5 kg Cooler, +3.6 pp, +5 yr warranty
AIKO-G670-MCH72Mw 670 W 24.80% -0.260 28.2 kg Cooler, lighter, +3.6 pp
RS9-650M-E1 650 W 20.92% -0.340 33.5 kg -10 W, -0.3 pp
RS9-655M-E1 655 W 21.09% -0.340 33.5 kg Very close match
RS9-665M-E1 665 W 21.41% -0.340 33.5 kg Very close match
RS9-670M-E1 670 W 21.57% -0.340 33.5 kg +10 W, +0.3 pp
AIKO-A805-GRH78Dw 805 W 25.10% -0.260 39.8 kg +145 W, cooler, +3.9 pp
AIKO-A800-GRH78Dw 800 W 24.90% -0.260 39.8 kg +140 W, cooler, +3.6 pp
AIKO-A795-GRH78Dw 795 W 24.80% -0.260 39.8 kg +135 W, cooler, +3.6 pp
AIKO-A790-GRH78Dw 790 W 24.60% -0.260 39.8 kg +130 W, cooler, +3.4 pp
TSM-NEG21C.20Q-760 760 W 24.50% -0.260 38.3 kg +100 W, cooler, +3.2 pp

Found 1390 panels of the same or similar size to this one, within ±10 mm. See them here Found 1400 panels of the same or similar size to this one, within ±25 mm. See them here Found 1400 panels of the same or similar size to this one, within ±50 mm. See them here Found 1432 panels of the same or similar size to this one, within ±100 mm. See them here

Common questions

6 answered
What warranty comes with the Renesola RS9-650~670M-E1 solar panels?
The RS9-650~670M-E1 series carries a 12-year product warranty and a 25-year linear power output warranty. Renesola guarantees that after 25 years of operation the module will retain at least 80% of its initial rated power. These terms are in line with Tier 1 industry standards and confirm the long-term reliability of the series.
Are Renesola RS9-670M-E1 panels a good fit for warehouse or agricultural building rooftops?
Yes, that is one of the primary target applications for this series. A peak power of up to 670 Wp and module efficiency reaching 21.6% maximize energy yield per square meter of available roof space. The MBB half-cut cell layout reduces losses from partial shading caused by HVAC units or skylights, which are common on large flat commercial rooftops.
What does N-type cell technology mean in the RS9-650~670M-E1, and why does it matter?
N-type cells are phosphorus-doped rather than boron-doped, which eliminates light-induced degradation (LID) common in older P-type modules. In practice this means more stable output over the panel's lifetime, a lower temperature coefficient, and better performance at elevated temperatures. The use of gallium-doped wafers provides additional protection against LeTID degradation.
How do Renesola RS9-650~670M-E1 panels perform in winter and overcast conditions?
The RS9-650~670M-E1 series features an excellent IAM (incident angle modifier) response and strong low-irradiance performance, translating to higher energy output at dawn, dusk, and on cloudy days. The MBB half-cut design also minimizes internal resistive losses. In a temperate climate, installations using these modules typically achieve a higher annual energy yield than older modules with a comparable STC power rating.
Is the Renesola RS9-650~670M-E1 a bifacial panel?
No, the RS9-650~670M-E1 is a monofacial module with a standard back sheet. If you need additional energy gain from ground-reflected irradiance, Renesola offers the MBG variant in the same family, which features a dual-glass construction and bifacial cell layout. The RS9-650~670M-E1 is well suited for installations where bifacial gains are limited, such as dark-membrane rooftops.
Is Renesola a reliable manufacturer, and is the RS9-650~670M-E1 still available?
Renesola holds Tier 1 bankability status according to Bloomberg NEF, indicating financial stability and consistent supply. The RS9-650~670M-E1 series is actively sold and has not been discontinued. Modules are certified to IEC 61215, IEC 61730, and carry ISO 9001, ISO 14001, and ISO 45001 management system certifications.
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