--- title: "Resun Solar RS9K645M 645W Solar Panel - Specs & Review | ComparePV" description: "Resun Solar RS9K645M 645W solar panel. Specs: 22.79% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/resun-solar-rs9k645m" updated: 2026-09-11 --- # Resun Solar RS9K645M Light for its output, no clear weak spot 5,677 panels in the 545-745 W band, all technologies ## Identity - **Manufacturer:** Resun Solar - **Model:** RS9K645M - **Series:** RS9K-M - **Rated power:** 645 W - **Cell technology:** Monocrystalline ## How it compares Compared against 545-745 W band, all technologies (5677 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 645 W | 610 W | Typical | | | 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 (kg) | 30.9 kg | 32.5 kg | Strong - top 13% | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | 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 | ### Strengths - **47.9 kg per kWp** - Top 13% of the 545-745 W band, against a median of 53.0. - **Best for:** Commercial, utility-scale and shaded-installations. ## Specification ### Electrical - **Rated power (Pmax):** 645 W - **Efficiency:** 22.79 % - **Voltage at Pmax (Vmp):** 37.20 V - **Current at Pmax (Imp):** 17.34 A - **Open-circuit voltage (Voc):** 44.80 V - **Short-circuit current (Isc):** 18.33 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 count:** 120 ### Physical - **Length:** 2172 mm - **Width:** 1303 mm - **Thickness:** 35 mm - **Weight:** 30.9 kg - **Area:** 2.83 m2 - **Power density:** 227.9 Wp/m2 ### Warranty and degradation - **Product warranty:** 15 years - **Performance warranty:** 30 years - **Annual degradation:** 0.50 % - **Output after 30 years:** 545 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 3005 of 14005 | | Power density | 2773 of 14005 | | Temperature coefficient | 6093 of 14005 | | Weight | 1967 of 14005 | | Warranty | 21 of 14005 | ## About this series 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. ## Notable figures - 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 ## Questions ### 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. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/RS9K-M-615-645W-6f8b4837fe84.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, lighter, +2.4 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +35 W, cooler, +2.4 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +30 W, cooler, +2.2 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +2.2 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +50 W, cooler, +2.1 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | Cooler, lighter, +2.0 pp | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | +25 W, cooler, +2.0 pp | | [Resun Solar RS9K-M-DG-610](https://comparepv.com/panel/resun-solar-rs9k-m-dg-610) | 610 W | -35 W, heavier, -1.2 pp | | [Resun Solar RS9K-M-DG-615](https://comparepv.com/panel/resun-solar-rs9k-m-dg-615) | 615 W | -30 W, heavier, -1.1 pp | | [Resun Solar RS9K-M-DG-620](https://comparepv.com/panel/resun-solar-rs9k-m-dg-620) | 620 W | -25 W, heavier, -0.9 pp | | [Resun Solar RS9K-M-DG-625](https://comparepv.com/panel/resun-solar-rs9k-m-dg-625) | 625 W | -20 W, heavier, -0.7 pp | | [Resun Solar RS9K-M-DG-630](https://comparepv.com/panel/resun-solar-rs9k-m-dg-630) | 630 W | -15 W, heavier, -0.5 pp | | [Resun Solar RS9K-M-DG-635](https://comparepv.com/panel/resun-solar-rs9k-m-dg-635) | 635 W | -10 W, heavier, -0.3 pp | | [Gamko New Energy GKA210N120](https://comparepv.com/panel/gamko-new-energy-gka210n120) | 680 W | +35 W, hotter, +1.2 pp | | [Gamko New Energy GKA210N120-675](https://comparepv.com/panel/gamko-new-energy-gka210n120-675) | 675 W | +30 W, hotter, +1.1 pp | | [Q-SUN Solar QN-670HJT-01](https://comparepv.com/panel/q-sun-solar-qn-670hjt-01) | 670 W | Cooler, heavier, +0.9 pp | --- Source: https://comparepv.com/panel/resun-solar-rs9k645m 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.