--- title: "Ulica Solar UL-665M-132DG 665W Solar Panel - Specs & Review | ComparePV" description: "Ulica Solar UL-665M-132DG 665W solar panel. Specs: 21.41% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/ulica-solar-ul-665m-132dg" updated: 2026-09-11 --- # Ulica Solar UL-665M-132DG Middle of its segment, weak in heat 249 panels in the segment TOPCon 650-700 W ## Identity - **Manufacturer:** Ulica Solar - **Model:** UL-665M-132DG - **Series:** Double-glass bifacial module UL-655\|660\|665\|670M-132DG - **Rated power:** 665 W - **Cell technology:** TOPCon - **Bifacial:** yes ## How it compares Compared against segment TOPCon 650-700 W (249 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 665 W | 665 W | Typical | | | Module efficiency | 21.41% | 22.40% | Weak - bottom 10% | 8,280 | | Power density | 214.1 | 223.7 | Weak - bottom 9% | 8,250 | | Temperature coefficient | -0.340 | -0.290 | Weak - bottom 6% | 8,778 | | Weight (kg) | 37.3 kg | 34.6 kg | Weak - bottom 20% | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 21.41% | 22.40% | Weak - bottom 10% | 8,280 | | Power density | 214.1 | 223.7 | Weak - bottom 9% | 8,250 | | Temperature coefficient | -0.340 | -0.290 | Weak - bottom 6% | 8,778 | | Weight per kWp | 56.1 | 53.2 | Weak - bottom 20% | 10,380 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Watch out for - **-0.340 %/°C temperature coefficient** - Bottom 6% of the TOPCon 650-700 W segment, against a median of -0.290. Ranked 8,778th in the whole database. - **214.1 watts per square metre** - Bottom 9% of the TOPCon 650-700 W segment, against a median of 223.7. Ranked 8,250th in the whole database. - **21.41% module efficiency** - Bottom 10% of the TOPCon 650-700 W segment, against a median of 22.40%. Ranked 8,280th in the whole database. - **Best for:** Commercial and utility-scale. - **Not ideal for:** Hot climates, roofs where every square metre has to count and tight roof space. ## Specification ### Electrical - **Rated power (Pmax):** 665 W - **Efficiency:** 21.41 % - **Voltage at Pmax (Vmp):** 38.30 V - **Current at Pmax (Imp):** 17.36 A - **Open-circuit voltage (Voc):** 45.80 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:** -0.265 %/degC - **Temperature coefficient of Isc:** 0.049 %/degC - **NOCT:** 43 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** TOPCon - **Cell count:** 132 - **Bifacial:** yes ### Physical - **Length:** 2384 mm - **Width:** 1303 mm - **Thickness:** 35 mm - **Weight:** 37.3 kg - **Area:** 3.11 m2 - **Power density:** 214.1 Wp/m2 ### Warranty and degradation - **Product warranty:** 12 years - **Performance warranty:** 30 years - **Output guaranteed at end of warranty:** 85.0 % - **First-year degradation:** 1.00 % - **Annual degradation:** 0.40 % - **Output after 30 years:** 581 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 8280 of 14005 | | Power density | 8250 of 14005 | | Temperature coefficient | 8778 of 14005 | | Weight | 10380 of 14005 | | Warranty | 21 of 14005 | ## About this series The Ulica Solar Double-glass bifacial UL-655\|660\|665\|670M-132DG series comprises modules that combine a **glass-glass structure** with **bifacial operation**, allowing them to better utilize reflected light from the ground and operate more reliably in challenging mounting conditions. The use of **monocrystalline PERC cells** supports high efficiency under real-world conditions, while the rigid construction with tempered glass on both sides increases resistance to microcracks and accelerated degradation, which is important for long-term investments. These modules offer a **long-term power warranty** and a positive tolerance margin, making it easier to design installations without the risk of "underestimated" parameters. They are a good choice for PV farms, commercial rooftop and carport installations, and projects where durability, consistent quality, and predictable energy production are important. Compared to many competing panels, they stand out due to their combination of bifaciality and the glass-glass structure, which provides better protection for the module over time. ## Notable figures - Efficiency of 21.4% is 1.0pp below the \*\*TOPCon 650-700W\*\* median (22.4%) - At 214.1 W/m², this panel generates 9.6 W/m² less per unit area than \*\*TOPCon 650-700W\*\* median (223.7 W/m²) - At -0.34%/°C, loses 0.05pp more power per degree than \*\*TOPCon 650-700W\*\* median (-0.29%/°C) - At 37.3 kg (2.7 kg above \*\*TOPCon 650-700W\*\* median of 34.6 kg), requires checking roof load capacity - In the top 59% for efficiency among all TOPCon panels ## Questions ### What is bifacial technology in the Ulica Solar UL-655\|660\|665\|670M-132DG panels and is it actually worth it? Bifacial technology means the module generates power from both sides - front and rear. It captures extra reflected light from the ground, roof, or a light-colored surface beneath the array, which, with the right installation (e.g., over light gravel or reflective membrane), delivers a real energy yield gain, typically a few to over ten percent more than a monofacial module. The biggest benefits show up on PV farms and flat roofs with sufficient mounting clearance. ### What warranty comes with the Ulica Solar UL-655-670M-132DG modules? The series carries a 12-year product warranty covering material and workmanship defects, plus a 30-year linear power warranty with a positive power tolerance. This means that even after 30 years the module still has a guaranteed, predictable percentage of its initial power output, which supports bankable design for commercial installations and PV farms without the risk of underperforming energy yield projections. ### Does the glass-glass construction actually improve durability compared to standard modules with a rear backsheet? Yes. Tempered glass on both sides of the cells instead of a polymer backsheet provides much better protection against moisture ingress, microcracks, and accelerated PID degradation, especially under large temperature and humidity swings. This construction is also mechanically stiffer, which matters for installations exposed to wind, hail, or snow loads and for projects designed for stable, long-term operation. ### What installations are the Ulica Solar UL-655-670M-132DG panels best suited for - ground-mount farms, commercial roofs, or carports? This series is primarily designed for large-scale installations: ground-mounted PV farms, commercial and industrial rooftops, and carport structures, where bifacial operation and power output up to 670 Wp deliver a better power-to-area ratio. The large module format makes it less typical for small residential installations on sloped rooftops. ### What is the maximum power output of this series and which cells does it use? The UL-655\|660\|665\|670M-132DG series delivers up to 670 Wp, depending on the specific variant (655, 660, 665, or 670 Wp). It uses 132 monocrystalline PERC cells in a half-cut layout, which reduces resistive losses and improves module efficiency while also increasing resistance to partial shading, for example from soiling or mounting structure elements. ### Is the Ulica Solar UL-655\|660\|665\|670M-132DG series still available for purchase? No, production of this series has ended and the model is considered discontinued from the manufacturer's current lineup. Panels may still be available only from distributor stock while supplies last. When planning a new installation or expanding an existing PV farm built with these modules, it's worth checking stock availability in advance or considering a current equivalent from Ulica Solar's active product range. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/ulica-mono-perc-2384mm-655-670w-biffacial-dg35mm-240731-bf264266935a.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, lighter, +3.8 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | Cooler, lighter, +3.8 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | Cooler, lighter, +3.6 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +3.6 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +35 W, cooler, +3.6 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +30 W, cooler, +3.5 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | Cooler, lighter, +3.4 pp | | [Ulica Solar UL-655M-132DG](https://comparepv.com/panel/ulica-solar-ul-655m-132dg) | 655 W | -10 W, -0.3 pp | | [Ulica Solar UL-660M-132DG](https://comparepv.com/panel/ulica-solar-ul-660m-132dg) | 660 W | Very close match | | [Ulica Solar UL-670M-132DG](https://comparepv.com/panel/ulica-solar-ul-670m-132dg) | 670 W | Very close match | | [Ulica Solar UL-700M-132DGN](https://comparepv.com/panel/ulica-solar-ul-700m-132dgn) | 700 W | +35 W, cooler, +1.1 pp | | [Ulica Solar UL-705M-132DGN](https://comparepv.com/panel/ulica-solar-ul-705m-132dgn) | 705 W | +40 W, cooler, +1.3 pp | | [AIKO AIKO-A805-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a805-grh78dw) | 805 W | +140 W, cooler, +3.7 pp | | [AIKO AIKO-A800-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a800-grh78dw) | 800 W | +135 W, cooler, +3.5 pp | | [AIKO AIKO-A795-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a795-grh78dw) | 795 W | +130 W, cooler, +3.4 pp | | [AIKO AIKO-A790-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a790-grh78dw) | 790 W | +125 W, cooler, +3.2 pp | --- Source: https://comparepv.com/panel/ulica-solar-ul-665m-132dg 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.