--- title: "Suntech STP645S-H66-Nsh+ 645W Solar Panel - Specs & Review | ComparePV" description: "Suntech STP645S-H66-Nsh+ 645W solar panel. Specs: 23.90% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/suntech-stp645s-h66-nsh" updated: 2026-09-11 --- # Suntech STP645S-H66-Nsh+ Efficiency leader, no clear weak spot 1,086 panels in the segment TOPCon 600-650 W ## Identity - **Manufacturer:** Suntech - **Model:** STP645S-H66-Nsh+ - **Series:** Ultra V Pro 2.0 - **Rated power:** 645 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) | 645 W | 620 W | Strong - top 3% | | | Module efficiency | 23.90% | 22.80% | Strong - top 1% | 351 | | Power density | 238.8 | 227.7 | Strong - top 1% | 356 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight (kg) | 32.5 kg | 32.7 kg | Strong - top 21% | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 23.90% | 22.80% | Strong - top 1% | 351 | | Power density | 238.8 | 227.7 | Strong - top 1% | 356 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight per kWp | 50.4 | 53.1 | Strong - top 21% | 3,767 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Strengths - **23.90% module efficiency** - Top 1% of the TOPCon 600-650 W segment, against a median of 22.80%. Ranked 351st in the whole database. - **238.8 watts per square metre** - Top 1% of the TOPCon 600-650 W segment, against a median of 227.7. Ranked 356th in the whole database. - **50.4 kg per kWp** - Top 21% of the TOPCon 600-650 W segment, against a median of 53.1. - **Best for:** Residential, commercial and utility-scale. ## Specification ### Electrical - **Rated power (Pmax):** 645 W - **Efficiency:** 23.90 % - **Voltage at Pmax (Vmp):** 41.64 V - **Current at Pmax (Imp):** 15.49 A - **Open-circuit voltage (Voc):** 50.10 V - **Short-circuit current (Isc):** 16.37 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.290 %/degC - **Temperature coefficient of Voc:** -0.250 %/degC - **Temperature coefficient of Isc:** 0.046 %/degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** TOPCon - **Cell count:** 132 - **Bifacial:** yes ### Physical - **Length:** 2382 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 32.5 kg - **Area:** 2.70 m2 - **Power density:** 238.8 Wp/m2 ### Warranty and degradation - **Product warranty:** 15 years - **Performance warranty:** 30 years - **Output guaranteed at end of warranty:** 87.4 % - **First-year degradation:** 1.00 % - **Annual degradation:** 0.40 % - **Output after 30 years:** 564 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 351 of 14005 | | Power density | 356 of 14005 | | Temperature coefficient | 2165 of 14005 | | Weight | 3767 of 14005 | | Warranty | 21 of 14005 | ## About this series The Suntech Ultra V Pro 2.0 series is a new generation of bifacial modules designed to squeeze maximum energy out of every square meter of roof or ground-mounted space. The panel is built on **half-cut N-type TOPCon cells** arranged in a transparent black bifacial design, allowing the rear side of the module to capture light reflected from the surrounding surface and boost real-world energy yield without expanding the installation footprint. The **multi-busbar technology** improves current collection and reduces resistive losses, translating into higher long-term reliability. The module also stands out for its strong **low-light performance**, generating power more efficiently than older-generation designs on cloudy days and during morning and evening hours, which matters in Poland's variable sunlight conditions. Its reinforced mechanical construction supports installation in locations exposed to heavy snow and wind loads. The manufacturer backs the series with a **30-year linear warranty** and low annual power degradation, making it an appealing choice both for investors in commercial installations and for homeowners seeking a durable solution with a stable return on investment over decades. ## Notable figures - Efficiency of 23.9% is 1.1pp above the \*\*TOPCon 600-650W\*\* median (22.8%) - 238.8 W/m² power density - 11.1 W/m² more than \*\*TOPCon 600-650W\*\* median (227.7 W/m²), more power per roof area - At -0.29%/°C, hot weather performance is typical for \*\*TOPCon 600-650W\*\* panels - 80% bifaciality enables rear-side power generation, boosting yield by 4-12% on reflective surfaces - Ranked #351 out of 14005 panels for efficiency in the database ## Questions ### What warranty comes with the Suntech Ultra V Pro 2.0 solar panels? The Ultra V Pro 2.0 series comes with a 25-year product warranty and a 30-year linear power warranty, guaranteeing high cell performance over three decades of operation. As a Tier 1 manufacturer, Suntech offers financial stability that supports warranty claim fulfillment, while low annual power degradation ensures a predictable return on investment even after 25-30 years of use. ### What does bifacial mean for the Ultra V Pro 2.0, and is it worth it? The bifacial design lets the rear side of the module capture light reflected from the ground, roof, or bright surfaces, generating extra energy without increasing the installation footprint. Depending on the surrounding albedo, gains can range from a few to over ten percent more annual energy yield. It pays off especially on light-colored ground surfaces, flat roofs with gravel or membrane, and installations mounted higher above the surface. ### How does N-Type TOPCon technology in the Ultra V Pro 2.0 differ from older PERC cells? N-Type TOPCon cells have lower resistive losses and reduced light-induced degradation compared to older P-Type PERC cells, resulting in higher efficiency and longer module lifespan. In the Ultra V Pro 2.0, TOPCon combined with multi busbar technology improves current collection and long-term stability, allowing the panel to reach a maximum power output of up to 650 Wp while maintaining low annual degradation. ### Do Ultra V Pro 2.0 panels perform well on cloudy days and in low-light conditions? Yes, thanks to TOPCon technology the module delivers strong low-light performance, generating energy more efficiently than older-generation designs during mornings, evenings, and cloudy days. This is particularly relevant in Poland's climate, where much of the year features diffused light conditions, and better low-irradiance efficiency translates into higher real-world annual energy yield. ### Is the Ultra V Pro 2.0 suitable for installations exposed to heavy snow and strong wind? Yes, the module features a reinforced mechanical structure designed for locations subject to heavy snow loads and strong winds, making it suitable for both pitched roofs and ground-mounted installations in more demanding climate conditions. This high mechanical durability also supports the long-term parameter stability covered by the 30-year linear power warranty. ### How many Ultra V Pro 2.0 panels are needed for a 10 kWp installation? With a maximum power of 650 Wp per module, roughly 15-16 Ultra V Pro 2.0 panels are needed to reach a system size of about 10 kWp. The high per-unit power output means fewer panels are required to achieve the target system capacity, which shortens installation time and makes more efficient use of available roof or ground space. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/STP630-650S-H66-Nsh-38423a1346b0.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, lighter, +1.3 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +35 W, lighter, +1.3 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +30 W, lighter, +1.1 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +1.1 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +50 W, cooler, +1.0 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | Cooler, lighter, +0.9 pp | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | Cooler, lighter, +0.9 pp | | [Suntech STP605S-H66-Nsh+](https://comparepv.com/panel/wuxi-suntech-power-co-ltd-stp605s-h66-nsh) | 605 W | -40 W, -1.5 pp | | [Suntech STP610S-H66-Nsh+](https://comparepv.com/panel/wuxi-suntech-power-co-ltd-stp610s-h66-nsh) | 610 W | -35 W, -1.3 pp | | [Suntech STP615S-H66-Nsh+](https://comparepv.com/panel/wuxi-suntech-power-co-ltd-stp615s-h66-nsh) | 615 W | -30 W, -1.1 pp | | [Suntech STP620S-H66-Nsh+](https://comparepv.com/panel/wuxi-suntech-power-co-ltd-stp620s-h66-nsh) | 620 W | -25 W, -0.9 pp | | [Suntech STP625S-H66-Nsh+](https://comparepv.com/panel/wuxi-suntech-power-co-ltd-stp625s-h66-nsh) | 625 W | -20 W, -0.8 pp | | [Suntech STP630S-H66-Nsh+](https://comparepv.com/panel/suntech-stp630s-h66-nsh) | 630 W | -15 W, -0.6 pp | | [Suntech STP635S-H66-Nsh+](https://comparepv.com/panel/suntech-stp635s-h66-nsh) | 635 W | -10 W, -0.4 pp | | [Suntech STP640S-H66-Nsh+](https://comparepv.com/panel/suntech-stp640s-h66-nsh) | 640 W | Very close match | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +55 W, cooler, +1.1 pp | --- Source: https://comparepv.com/panel/suntech-stp645s-h66-nsh Not in this file, on the page: the I-V and temperature curves lifted from the manufacturer's datasheet, a thirty-year output simulator, a bifacial gain calculator and alternatives filtered by how closely they match these dimensions.