--- title: "Yingli YL655DF66 f/2 655W Solar Panel - Specs & Review | ComparePV" description: "Yingli YL655DF66 f/2 655W solar panel. Specs: 21.10% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/yingli-yl655df66-f-2" updated: 2026-09-11 --- # Yingli YL655DF66 f/2 Middle of its segment, heavy for its output 320 panels in the segment PERC 650-700 W ## Identity - **Manufacturer:** Yingli - **Model:** YL655DF66 f/2 - **Series:** YLM 3.0 Plus 1 - **Rated power:** 655 W - **Cell technology:** PERC - **Bifacial:** yes ## How it compares Compared against segment PERC 650-700 W (320 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 655 W | 660 W | Weak - bottom 25% | | | Module efficiency | 21.10% | 21.25% | Typical | 9,297 | | Power density | 210.9 | 212.5 | Weak - bottom 24% | 9,459 | | Temperature coefficient | -0.340 | -0.340 | Typical | 8,778 | | Weight (kg) | 38.4 kg | 34.5 kg | Weak - bottom 13% | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 21.10% | 21.25% | Typical | 9,297 | | Power density | 210.9 | 212.5 | Weak - bottom 24% | 9,459 | | Temperature coefficient | -0.340 | -0.340 | Typical | 8,778 | | Weight per kWp | 58.6 | 52.3 | Weak - bottom 13% | 11,816 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Watch out for - **58.6 kg per kWp** - Bottom 13% of the PERC 650-700 W segment, against a median of 52.3. - **210.9 watts per square metre** - Bottom 24% of the PERC 650-700 W segment, against a median of 212.5. - **Best for:** Commercial and utility-scale. - **Not ideal for:** Weight-limited structures and roofs where every square metre has to count. ## Specification ### Electrical - **Rated power (Pmax):** 655 W - **Efficiency:** 21.10 % - **Voltage at Pmax (Vmp):** 37.70 V - **Current at Pmax (Imp):** 17.38 A - **Open-circuit voltage (Voc):** 45.50 V - **Short-circuit current (Isc):** 18.42 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:** PERC - **Cell count:** 132 - **Bifacial:** yes ### Physical - **Length:** 2384 mm - **Width:** 1303 mm - **Thickness:** 35 mm - **Weight:** 38.4 kg - **Area:** 3.11 m2 - **Power density:** 210.9 Wp/m2 ### Warranty and degradation - **Product warranty:** 12 years - **Performance warranty:** 30 years - **Output guaranteed at end of warranty:** 85.0 % - **First-year degradation:** 2.00 % - **Annual degradation:** 0.45 % - **Output after 30 years:** 556 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 9297 of 14005 | | Power density | 9459 of 14005 | | Temperature coefficient | 8778 of 14005 | | Weight | 11816 of 14005 | | Warranty | 21 of 14005 | ## About this series The Yingli YLM 3.0 Plus 1 series is designed for high energy production on limited mounting surfaces, making it ideal where every square meter of roof or field space counts. These modules utilize **p-type monocrystalline PERC solar cells**, and their refined interconnection architecture ensures stable performance even under partial shading and uneven irradiance, common in many Polish installations. A key feature is the **glass-glass construction**, which enhances environmental resistance and facilitates maintaining parameters over a long period - a real advantage in projects exposed to wind, humidity, and temperature fluctuations. The series targets **high reliability in challenging conditions** thanks to high-quality lamination materials and robust construction. The YLM 3.0 Plus 1 is a solid choice for commercial and utility-scale PV projects, where dependable power generation and long-term durability take precedence over catalog specifications. ## Notable figures - Efficiency of 21.1% matches the \*\*PERC 650-700W\*\* median - Power density of 210.9 W/m² matches the \*\*PERC 650-700W\*\* median - At -0.34%/°C, hot weather performance is typical for \*\*PERC 650-700W\*\* panels - Weight of 38.4 kg is 3.9 kg above \*\*PERC 650-700W\*\* median (34.5 kg) - verify structural support - Bifaciality factor of 70% can add 4-10% extra yield with reflective mounting surface ## Questions ### What is the maximum power output of the Yingli YLM 3.0 Plus 1 panel? The top variant of the YLM 3.0 Plus 1 series reaches up to 670 Wp, thanks to 132 large p-type monocrystalline PERC cells. This allows high energy yield from fewer modules, which meaningfully reduces installation time and mounting structure costs in commercial installations and utility-scale PV farms. ### How does the glass-glass construction of the YLM 3.0 Plus 1 differ from standard glass-backsheet panels? Unlike typical panels with a rear backsheet layer, the YLM 3.0 Plus 1 encapsulates its cells between two glass panes. This design better protects the cells from moisture, microcracks, and PID degradation, resulting in a slower power decline over time and greater resistance to harsh weather conditions such as strong wind or hail. ### What warranty comes with the Yingli YLM 3.0 Plus 1 panels? The manufacturer offers a 12-year product warranty along with a 30-year linear power output warranty. This means that after 30 years of operation, the panel should still retain the guaranteed minimum percentage of its initial output, a standard expectation for modern glass-glass modules from a tier 1 manufacturer. ### Is the YLM 3.0 Plus 1 suited for large-scale PV farms or more for residential roofs? This series is designed primarily for commercial installations and utility-scale PV farms, where predictable energy yield and long-term durability matter more than raw datasheet figures. Its large format and high unit power (up to 670 Wp) make it better suited to large mounting areas than to a typical single-family sloped roof. ### Are the YLM 3.0 Plus 1 panels bifacial, generating power from the rear side? No, the YLM 3.0 Plus 1 series uses standard monofacial PERC cell architecture. The glass-glass construction here is meant to boost durability and environmental resistance, not add rear-side power generation - this sets it apart from bifacial models in Yingli's lineup. ### Who manufactures the YLM 3.0 Plus 1 panels, and is it a reliable tier 1 supplier? The YLM 3.0 Plus 1 panels are made by Yingli, a Chinese manufacturer with decades of industry experience, classified as a tier 1 supplier. This reflects solid financial standing and proven manufacturing capacity, which matters when pursuing warranty claims over the multi-decade lifespan of a PV installation. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/1753059323642-81ad30d6fda0.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, lighter, +4.1 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | Cooler, lighter, +4.1 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | Cooler, lighter, +3.9 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +3.9 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +45 W, cooler, +3.9 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +40 W, cooler, +3.8 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | Cooler, lighter, +3.7 pp | | [Yingli YL645DF66 f/2](https://comparepv.com/panel/yingli-yl645df66-f-2) | 645 W | -10 W, -0.3 pp | | [Yingli YL650DF66 f/2](https://comparepv.com/panel/yingli-yl650df66-f-2) | 650 W | -0.2 pp | | [Yingli YL660D-45f 1/2](https://comparepv.com/panel/yingli-yl660d-45f-1-2) | 660 W | Lighter, -5 yr warranty | | [AIKO AIKO-A805-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a805-grh78dw) | 805 W | +150 W, cooler, +4.0 pp | | [AIKO AIKO-A800-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a800-grh78dw) | 800 W | +145 W, cooler, +3.8 pp | | [AIKO AIKO-A795-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a795-grh78dw) | 795 W | +140 W, cooler, +3.7 pp | | [AIKO AIKO-A790-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a790-grh78dw) | 790 W | +135 W, cooler, +3.5 pp | | [Trina Solar TSM-NEG21C.20Q-760](https://comparepv.com/panel/trina-solar-tsm-neg21c-20q-760) | 760 W | +105 W, cooler, +3.4 pp | | [AIKO AIKO-A785-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a785-grh78dw) | 785 W | +130 W, cooler, +3.3 pp | --- Source: https://comparepv.com/panel/yingli-yl655df66-f-2 Not in this file, on the page: a thirty-year output simulator, a bifacial gain calculator and alternatives filtered by how closely they match these dimensions.