--- title: "Suntech STP425S-C54/Umh Solar Panel: Specs & Datasheet | ComparePV" description: "Suntech STP425S-C54/Umh solar panel. Specs: 21.70% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/suntech-stp425s-c54-umh" image: "https://comparepv.com/og/panel/suntech-stp425s-c54-umh.png" updated: 2026-09-11 --- # Suntech STP425S-C54/Umh Middle of its segment, weak in heat 1,220 panels in the segment TOPCon 400-450 W ## Identity - **Manufacturer:** Suntech - **Model:** STP425S-C54/Umh - **Series:** Ultra V Pro mini - **Rated power:** 425 W - **Cell technology:** TOPCon ## How it compares Compared against segment TOPCon 400-450 W (1220 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 425 W | 435 W | Typical | | | Module efficiency | 21.70% | 22.00% | Typical | 7,485 | | Power density | 217.4 | 220.2 | Typical | 7,385 | | Temperature coefficient | -0.320 | -0.290 | Weak - bottom 7% | 8,376 | | Weight (kg) | 22.1 kg | 22.0 kg | Typical | | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 7% | 9,912 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 21.70% | 22.00% | Typical | 7,485 | | Power density | 217.4 | 220.2 | Typical | 7,385 | | Temperature coefficient | -0.320 | -0.290 | Weak - bottom 7% | 8,376 | | Weight per kWp | 52.0 | 51.5 | Typical | 5,509 | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 7% | 9,912 | ### Watch out for - **-0.320 %/°C temperature coefficient** - Bottom 7% of the TOPCon 400-450 W segment, against a median of -0.290. Ranked 8,376th in the whole database. - **25 year performance warranty** - Bottom 7% of the TOPCon 400-450 W segment, against a median of 30 yrs. Ranked 9,912th in the whole database. - **Best for:** Residential. - **Not ideal for:** Hot climates and owners who want a long output guarantee. ## Specification ### Electrical - **Rated power (Pmax):** 425 W - **Efficiency:** 21.70 % - **Voltage at Pmax (Vmp):** 32.25 V - **Current at Pmax (Imp):** 13.18 A - **Open-circuit voltage (Voc):** 38.08 V - **Short-circuit current (Isc):** 14.10 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.320 %/degC - **Temperature coefficient of Voc:** -0.260 %/degC - **Temperature coefficient of Isc:** 0.046 %/degC - **NOCT:** 42 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** TOPCon - **Cell count:** 108 ### Physical - **Length:** 1724 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 22.1 kg - **Area:** 1.96 m2 - **Power density:** 217.4 Wp/m2 ### Warranty and degradation - **Product warranty:** 12 years - **Performance warranty:** 25 years - **Output guaranteed at end of warranty:** 89.4 % - **First-year degradation:** 1.00 % - **Annual degradation:** 0.40 % - **Output after 30 years:** 371 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 7485 of 14129 | | Power density | 7385 of 14129 | | Temperature coefficient | 8376 of 14129 | | Weight | 5509 of 14129 | | Warranty | 9912 of 14129 | ## About this series Suntech Ultra V Pro mini photovoltaic panels represent a breakthrough in the category of compact modules, utilizing **advanced N-type TOPCon cell technology** to achieve maximum efficiency on limited surfaces. This series was designed with prosumer installations in mind, where the optimal utilization of challenging roof areas while maintaining an aesthetic appearance is of key importance. Thanks to the use of **high-density cell packing technology**, these modules offer a significantly higher energy yield per square meter than standard competing solutions. This solves the problem of limited installation space, allowing for the construction of an efficient system even on small or complex roofs. The innovative design based on **MBB multi-busbar connections** minimizes resistive losses and improves current flow, which translates into stable operation across a wide range of weather conditions. Suntech Ultra V Pro mini stands out in the market with its exceptional resistance to degradation and an excellent temperature coefficient, guaranteeing the long-term profitability of the investment. It is an ideal choice for homeowners seeking **maximum reliability and high efficiency** enclosed in a lightweight, handy form that facilitates installation and reduces the load on the roof structure while maintaining **excellent performance in low light**. ## Notable figures - At 21.7% efficiency, this panel is on par with typical \*\*TOPCon 400-450W\*\* modules - At 217.4 W/m² power density, roof space requirements are typical for \*\*TOPCon 400-450W\*\* panels - -0.32%/°C temperature coefficient - 0.03pp worse than \*\*TOPCon 400-450W\*\* median (-0.29%/°C), expect higher hot weather losses - Ranked #7485 out of 14129 panels for efficiency in the database ## Questions ### What is the maximum power output of the Suntech Ultra V Pro mini panels? The Ultra V Pro mini series reaches a maximum power output of up to 430 Wp. This is achieved through N-type TOPCon cells and high-density cell packing technology, allowing a compact module to generate more energy per square meter than traditional PERC panels of similar dimensions. ### Are the Suntech Ultra V Pro mini panels suitable for small or complex roofs? Yes, the mini series is specifically designed for limited or irregular roof surfaces. High-density cell packing maximizes energy yield from a small footprint, making it a strong fit for roofs with dormers, chimneys, or complex geometry where standard large-format modules are difficult to fit. ### What warranty comes with the Suntech Ultra V Pro mini panels? The manufacturer provides a 12-year product warranty and a 25-year power performance warranty. This means the modules are covered long-term against manufacturing defects as well as excessive power output degradation, which is standard for Tier 1 solar panels. ### How does the TOPCon technology in the Ultra V Pro mini differ from standard PERC panels? N-type TOPCon cells feature an additional passivation layer that reduces carrier recombination and increases efficiency compared to older P-type PERC cells. In practice, this results in higher energy yield, a better temperature coefficient, and slower degradation over the module's lifetime. ### Are the Suntech Ultra V Pro mini panels bifacial? No, the Ultra V Pro mini series uses monofacial panels. The module generates energy only from the front side, which is a typical solution for rooftop installations where the rear side lacks sufficient reflected light exposure to justify bifacial technology. ### How does MBB (multi-busbar) technology affect performance in low-light conditions? MBB technology increases the number of current-carrying paths between cells, reducing resistive losses and improving current collection even at lower irradiance levels. As a result, Ultra V Pro mini panels maintain more stable energy production during early morning, late afternoon, and overcast days. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/EN_Ultra_V_Pro_mini_N-type_STP430S_C54_Umh-fe7af5161407.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [Maxeon SPR-MAX7-475](https://comparepv.com/panel/maxeon-spr-max7-475) | 475 W | +50 W, +2.3 pp, +15 yr warranty | | [Just Solar JST-EDMH-(445-465)W-TD (465W class)](https://comparepv.com/panel/just-solar-jst-edmh-445-465-w-td-465w-class) | 465 W | +40 W, +2.1 pp, +5 yr warranty | | [JA Solar JAT54S40-475/LR](https://comparepv.com/panel/ja-solar-jat54s40-475-lr) | 475 W | +50 W, cooler, +2.1 pp | | [Tongwei TWMNH-48HW475](https://comparepv.com/panel/tongwei-solar-twmnh-48hw475) | 475 W | +50 W, +2.1 pp, +5 yr warranty | | [Astronergy CHSM48RN(DG)/F-BH-475](https://comparepv.com/panel/astronergy-chint-new-energy-technology-co-ltd-chsm48rn-dg-f-bh-475) | 475 W | +50 W, +2.1 pp, +5 yr warranty | | [AIKO AIKO-A475-MCE54Mw](https://comparepv.com/panel/aiko-aiko-a475-mce54mw) | 475 W | +50 W, cooler, +2.1 pp | | [AIKO AIKO-A475-MAH54Mw](https://comparepv.com/panel/aiko-aiko-a475-mah54mw) | 475 W | +50 W, cooler, +2.1 pp | | [Suntech STP390S-C54/Umh](https://comparepv.com/panel/suntech-stp390s-c54-umh) | 390 W | -35 W, hotter, -1.8 pp | | [Suntech STP395S-C54/Umhm](https://comparepv.com/panel/wuxi-suntech-power-co-ltd-suntech-stp395s-c54-umhm) | 395 W | -30 W, hotter, -1.5 pp | | [Suntech STP395S-C54/Umh](https://comparepv.com/panel/suntech-stp395s-c54-umh) | 395 W | -30 W, hotter, -1.5 pp | | [Suntech STP400S-C54/Umhm](https://comparepv.com/panel/wuxi-suntech-power-co-ltd-suntech-stp400s-c54-umhm) | 400 W | -25 W, hotter, -1.2 pp | | [Suntech STP400S-C54/Umh](https://comparepv.com/panel/suntech-stp400s-c54-umh) | 400 W | -25 W, hotter, -1.2 pp | | [Suntech STP405S-C54/Umhm](https://comparepv.com/panel/wuxi-suntech-power-co-ltd-suntech-stp405s-c54-umhm) | 405 W | -20 W, hotter, -1.0 pp | | [Suntech STP405S-C54/Umh](https://comparepv.com/panel/suntech-stp405s-c54-umh) | 405 W | -20 W, hotter, -1.0 pp | | [Longi Solar LR7-54HJD-510M](https://comparepv.com/panel/longi-lr7-54hjd-510m) | 510 W | +85 W, cooler, +3.3 pp | | [AIKO AIKO-A495-MCE54Mw](https://comparepv.com/panel/aiko-aiko-a495-mce54mw) | 495 W | +70 W, cooler, +3.1 pp | --- Source: https://comparepv.com/panel/suntech-stp425s-c54-umh 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.