--- title: "Resun Solar RS9K-M-DG-640 640W Solar Panel - Specs & Review | ComparePV" description: "Resun Solar RS9K-M-DG-640 640W solar panel. Specs: 22.61% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/resun-solar-rs9k-m-dg-640" updated: 2026-09-11 --- # Resun Solar RS9K-M-DG-640 Middle of its segment, weak in heat 1,086 panels in the segment TOPCon 600-650 W ## Identity - **Manufacturer:** Resun Solar - **Model:** RS9K-M-DG-640 - **Series:** RS9K-M-DG - **Rated power:** 640 W - **Cell technology:** TOPCon - **Bifacial:** yes ## How it compares Compared against segment TOPCon 600-650 W (1086 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 640 W | 620 W | Strong - top 9% | | | Module efficiency | 22.61% | 22.80% | Typical | 3,643 | | Power density | 226.1 | 227.7 | Typical | 3,681 | | Temperature coefficient | -0.300 | -0.290 | Weak - bottom 19% | 6,093 | | Weight (kg) | 34.5 kg | 32.7 kg | Typical | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 22.61% | 22.80% | Typical | 3,643 | | Power density | 226.1 | 227.7 | Typical | 3,681 | | Temperature coefficient | -0.300 | -0.290 | Weak - bottom 19% | 6,093 | | Weight per kWp | 53.9 | 53.1 | Typical | 8,037 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Watch out for - **-0.300 %/°C temperature coefficient** - Bottom 19% of the TOPCon 600-650 W segment, against a median of -0.290. - **Not ideal for:** Hot climates. ## Specification ### Electrical - **Rated power (Pmax):** 640 W - **Efficiency:** 22.61 % - **Voltage at Pmax (Vmp):** 36.94 V - **Current at Pmax (Imp):** 17.33 A - **Open-circuit voltage (Voc):** 44.15 V - **Short-circuit current (Isc):** 18.35 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.300 %/degC - **Temperature coefficient of Voc:** -0.250 %/degC - **Temperature coefficient of Isc:** 0.045 %/degC - **NOCT:** 45 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** TOPCon - **Cell count:** 120 - **Bifacial:** yes ### Physical - **Length:** 2172 mm - **Width:** 1303 mm - **Thickness:** 35 mm - **Weight:** 34.5 kg - **Area:** 2.83 m2 - **Power density:** 226.1 Wp/m2 ### Warranty and degradation - **Product warranty:** 15 years - **Performance warranty:** 30 years - **Annual degradation:** 0.50 % - **Output after 30 years:** 541 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 3643 of 14005 | | Power density | 3681 of 14005 | | Temperature coefficient | 6093 of 14005 | | Weight | 8037 of 14005 | | Warranty | 21 of 14005 | ## About this series The RS9K-M-DG series consists of bifacial, dual-glass photovoltaic modules designed for investors who expect maximum durability and stable energy yield over decades of operation. At the core of the design are **monocrystalline N-type TOPCon cells with multi-busbar (MBB) technology**, which reduce internal power losses and boost conversion efficiency while lowering the risk of microcracks and busbar breakage. Combining this solution with **half-cell technology** significantly improves the module's resistance to the hot-spot effect caused by partial shading, meaningfully extending system lifespan in demanding installation conditions. The panels also stand out for their high **resistance to potential-induced degradation (anti-PID)**, allowing them to maintain stable energy output and lower the levelized cost of energy (LCOE) throughout their lifetime. Tempered front glass measuring 2.0+2.0 mm with an anti-reflective coating improves performance in low-light conditions, while certified resistance to wind and snow loads as well as salt mist and ammonia makes this series suitable for both rooftop installations and ground-mounted farms in harsh climates. The manufacturer backs the modules with a **30-year linear power warranty**, confirming confidence in the product's quality and long-term stability. RS9K-M-DG is the choice for installers and investors who prioritize reliability, strong return on investment, and reduced operational risk. ## Notable figures - At 22.6% efficiency, this panel is on par with typical \*\*TOPCon 600-650W\*\* modules - Power density of 226.1 W/m² matches the \*\*TOPCon 600-650W\*\* median - Temperature coefficient of -0.30%/°C matches the \*\*TOPCon 600-650W\*\* median - Weight of 34.5 kg is 1.8 kg above \*\*TOPCon 600-650W\*\* median (32.7 kg) - verify structural support - Ranked #3643 out of 14005 panels for efficiency in the database ## Questions ### Are RS9K-M-DG panels suitable for solar farms in harsh environments (coastal, industrial)? Yes, the RS9K-M-DG series is certified for resistance to salt mist and ammonia, making it suitable for coastal installations and agricultural sites with livestock, where ammonia concentrations can be high. The panels also withstand heavy wind and snow loads, making them a good fit for both ground-mount farms and rooftops in demanding weather conditions. ### What is TOPCon technology in the RS9K-M-DG and does it translate into real energy gains? TOPCon is an N-type monocrystalline cell technology with an additional passivation layer that reduces current losses and increases conversion efficiency compared to older PERC cells. In the RS9K-M-DG it's combined with multi-busbar (MBB), further reducing resistive losses and microcrack risk. In practice, this means higher energy yield from the same roof or ground area and lower power degradation over time. ### What's the difference between the product warranty and the power warranty for the RS9K-M-DG series? The product warranty covers 15 years and includes material and workmanship defects, such as frame or connector damage. The power warranty extends to 30 years, guaranteeing a minimum energy output level over the system's lifetime with linear degradation. This is longer than the market-standard 25 years, resulting in a lower real levelized cost of energy (LCOE) over the installation's full life cycle. ### Do bifacial RS9K-M-DG panels generate more energy than standard monofacial modules? Yes, thanks to the dual-glass bifacial construction, the module also captures light reflected off the ground onto the rear side of the cells. Depending on the albedo of the surface beneath the panels (e.g., light gravel, snow, white roofing), the additional energy gain can range from a few percent up to more than ten percent compared to a traditional monofacial module of the same nominal power. ### Does the half-cell technology in the RS9K-M-DG actually protect against hot-spot effects under partial shading? Yes, splitting cells into half-cut segments reduces power losses when part of the panel is shaded by leaves, a chimney, or a neighboring building. Smaller cells generate lower currents, which reduces heating in the shaded section and the risk of permanent damage to the module structure. This is a significant advantage for rooftop installations with uneven sun exposure throughout the day. ### What is the maximum power output of the RS9K-M-DG module, and how many panels are needed for a typical 10 kWp installation? The highest-power variants in the RS9K-M-DG series reach up to 650 Wp. At this power level, a roughly 10 kWp installation requires approximately 15-16 modules, reducing the number of panels, cable runs, and the roof or ground area needed compared to lower-wattage modules. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/RS9K-M-DG-610-650W-RETIE-version-e91a78585e66.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, lighter, +2.6 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +40 W, lighter, +2.6 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | Cooler, lighter, +2.4 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +2.4 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | Cooler, lighter, +2.2 pp | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | Cooler, lighter, +2.2 pp | | [AIKO AIKO-A640-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a640-mae72mw) | 640 W | Cooler, lighter, +2.2 pp | | [Resun Solar RS9K-M-DG-610](https://comparepv.com/panel/resun-solar-rs9k-m-dg-610) | 610 W | -30 W, -1.1 pp | | [Resun Solar RS9K-M-DG-615](https://comparepv.com/panel/resun-solar-rs9k-m-dg-615) | 615 W | -25 W, -0.9 pp | | [Resun Solar RS9K-M-DG-620](https://comparepv.com/panel/resun-solar-rs9k-m-dg-620) | 620 W | -20 W, -0.7 pp | | [Resun Solar RS9K-M-DG-625](https://comparepv.com/panel/resun-solar-rs9k-m-dg-625) | 625 W | -15 W, -0.5 pp | | [Resun Solar RS9K-M-DG-630](https://comparepv.com/panel/resun-solar-rs9k-m-dg-630) | 630 W | -10 W, -0.3 pp | | [Resun Solar RS9K-M-DG-635](https://comparepv.com/panel/resun-solar-rs9k-m-dg-635) | 635 W | Very close match | | [Gamko New Energy GKA210N120](https://comparepv.com/panel/gamko-new-energy-gka210n120) | 680 W | Hotter, lighter, +1.4 pp | | [Gamko New Energy GKA210N120-675](https://comparepv.com/panel/gamko-new-energy-gka210n120-675) | 675 W | Hotter, lighter, +1.2 pp | | [Q-SUN Solar QN-670HJT-01](https://comparepv.com/panel/q-sun-solar-qn-670hjt-01) | 670 W | +30 W, cooler, +1.1 pp | --- Source: https://comparepv.com/panel/resun-solar-rs9k-m-dg-640 Not in this file, on the page: the I-V and temperature curves lifted from the manufacturer's datasheet, a thirty-year output simulator and alternatives filtered by how closely they match these dimensions.