--- title: "Renesola RS9-660M-E1 660W Solar Panel - Specs & Review | ComparePV" description: "Renesola RS9-660M-E1 660W solar panel. Specs: 21.25% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/renesola-rs9-660m-e1" updated: 2026-09-11 --- # Renesola RS9-660M-E1 Middle of its segment, modest efficiency 109 panels in the segment N-type 650-700 W ## Identity - **Manufacturer:** Renesola - **Model:** RS9-660M-E1 - **Series:** RS9-650~670M-E1 - **Rated power:** 660 W - **Cell technology:** N-type ## How it compares Compared against segment N-type 650-700 W (109 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 660 W | 660 W | Typical | | | 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 (kg) | 33.5 kg | 33.5 kg | Typical | | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 7% | 9,798 | ### Full peer table | Measure | This panel | Segment median | Standing | 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 | ### Watch out for - **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. - **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. ## Specification ### Electrical - **Rated power (Pmax):** 660 W - **Efficiency:** 21.25 % - **Voltage at Pmax (Vmp):** 37.80 V - **Current at Pmax (Imp):** 17.47 A - **Open-circuit voltage (Voc):** 45.70 V - **Short-circuit current (Isc):** 18.53 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.340 %/degC - **Temperature coefficient of Voc:** -0.250 %/degC - **Temperature coefficient of Isc:** 0.040 %/degC - **NOCT:** 43 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** N-type - **Cell count:** 132 ### Physical - **Length:** 2384 mm - **Width:** 1303 mm - **Thickness:** 33 mm - **Weight:** 33.5 kg - **Area:** 3.11 m2 - **Power density:** 212.5 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:** 542 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 8904 of 14005 | | Power density | 8959 of 14005 | | Temperature coefficient | 8778 of 14005 | | Weight | 4172 of 14005 | | Warranty | 9798 of 14005 | ## Pros - **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%). ## Cons - **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. ## About this series 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. ## Notable figures - 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 ## Questions ### 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. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/rs9-650-670m-210-132-mono-facial-module-fc22c555394f.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, lighter, +3.9 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | Cooler, +3.9 pp, +5 yr warranty | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | Cooler, +3.8 pp, +5 yr warranty | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +3.8 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | Cooler, +3.8 pp, +5 yr warranty | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | Cooler, +3.6 pp, +5 yr warranty | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | Cooler, lighter, +3.6 pp | | [Renesola RS9-650M-E1](https://comparepv.com/panel/renesola-rs9-650m-e1) | 650 W | -10 W, -0.3 pp | | [Renesola RS9-655M-E1](https://comparepv.com/panel/renesola-rs9-655m-e1) | 655 W | Very close match | | [Renesola RS9-665M-E1](https://comparepv.com/panel/renesola-rs9-665m-e1) | 665 W | Very close match | | [Renesola RS9-670M-E1](https://comparepv.com/panel/renesola-rs9-670m-e1) | 670 W | +10 W, +0.3 pp | | [AIKO AIKO-A805-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a805-grh78dw) | 805 W | +145 W, cooler, +3.9 pp | | [AIKO AIKO-A800-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a800-grh78dw) | 800 W | +140 W, cooler, +3.6 pp | | [AIKO AIKO-A795-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a795-grh78dw) | 795 W | +135 W, cooler, +3.6 pp | | [AIKO AIKO-A790-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a790-grh78dw) | 790 W | +130 W, cooler, +3.4 pp | | [Trina Solar TSM-NEG21C.20Q-760](https://comparepv.com/panel/trina-solar-tsm-neg21c-20q-760) | 760 W | +100 W, cooler, +3.2 pp | --- Source: https://comparepv.com/panel/renesola-rs9-660m-e1 Not in this file, on the page: a thirty-year output simulator and alternatives filtered by how closely they match these dimensions.