--- title: "Suntech STP400S-C54/Umhb Solar Panel: Specs & Datasheet | ComparePV" description: "Suntech STP400S-C54/Umhb solar panel. Specs: 20.50% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/wuxi-suntech-power-co-ltd-stp400s-c54-umhb" image: "https://comparepv.com/og/panel/wuxi-suntech-power-co-ltd-stp400s-c54-umhb.png" updated: 2026-09-11 --- # Suntech STP400S-C54/Umhb Middle of its segment, modest efficiency 1,220 panels in the segment TOPCon 400-450 W ## Identity - **Manufacturer:** Suntech - **Model:** STP400S-C54/Umhb - **Series:** Ultra V mini - **Rated power:** 400 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) | 400 W | 435 W | Weak - bottom 1% | | | Module efficiency | 20.50% | 22.00% | Weak - bottom 2% | 11,389 | | Power density | 204.8 | 220.2 | Weak - bottom 2% | 11,450 | | Temperature coefficient | -0.340 | -0.290 | Weak - bottom 5% | 8,846 | | Weight (kg) | 21.0 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 | 20.50% | 22.00% | Weak - bottom 2% | 11,389 | | Power density | 204.8 | 220.2 | Weak - bottom 2% | 11,450 | | Temperature coefficient | -0.340 | -0.290 | Weak - bottom 5% | 8,846 | | Weight per kWp | 52.5 | 51.5 | Typical | 6,090 | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 7% | 9,912 | ### Watch out for - **20.50% module efficiency** - Bottom 2% of the TOPCon 400-450 W segment, against a median of 22.00%. Ranked 11,389th in the whole database. - **204.8 watts per square metre** - Bottom 2% of the TOPCon 400-450 W segment, against a median of 220.2. Ranked 11,450th in the whole database. - **-0.340 %/°C temperature coefficient** - Bottom 5% of the TOPCon 400-450 W segment, against a median of -0.290. Ranked 8,846th in the whole database. - **Best for:** Residential and shaded-installations. - **Not ideal for:** Tight roof space, roofs where every square metre has to count and hot climates. ## Specification ### Electrical - **Rated power (Pmax):** 400 W - **Efficiency:** 20.50 % - **Voltage at Pmax (Vmp):** 31.18 V - **Current at Pmax (Imp):** 12.83 A - **Open-circuit voltage (Voc):** 37.04 V - **Short-circuit current (Isc):** 13.73 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.340 %/degC - **Temperature coefficient of Voc:** -0.260 %/degC - **Temperature coefficient of Isc:** 0.050 %/degC - **NOCT:** 42 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** TOPCon - **Cell count:** 108 ### Physical - **Length:** 1722 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 21.0 kg - **Area:** 1.95 m2 - **Power density:** 204.8 Wp/m2 ### Warranty and degradation - **Product warranty:** 12 years - **Performance warranty:** 25 years - **Output guaranteed at end of warranty:** 84.8 % - **First-year degradation:** 2.00 % - **Annual degradation:** 0.55 % - **Output after 30 years:** 328 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 11389 of 14129 | | Power density | 11450 of 14129 | | Temperature coefficient | 8846 of 14129 | | Weight | 6090 of 14129 | | Warranty | 9912 of 14129 | ## About this series Suntech Ultra V mini modules are designed to offer **maximum power density** for every square meter of available roof area. Through the use of modern cells based on M10 silicon wafers and Multi-Busbar technology, these panels effectively minimize resistive losses and increase sunlight absorption. This solution ideally addresses the needs of homeowners with limited installation space, where every centimeter of the roof is critical to the final profitability of the investment. The **exceptionally low weight of the modules** facilitates logistics and installation without placing an excessive load on the roof structure, which is particularly important when modernizing older buildings. The innovative **Half-Cut** cell structure guarantees stable system performance even during periodic shading, clearly setting this series apart from standard solutions currently available on the market. Suntech Ultra V mini also offers **increased resistance to PID degradation** and excellent temperature coefficients, ensuring high electricity production even on hot days. By choosing these panels, Polish investors receive a product that combines elegant design with premium-class technology, fully optimized for a rapid return on investment. ## Notable figures - Module efficiency of 20.5% is 1.5pp below average for \*\*TOPCon 400-450W\*\* panels (median: 22.0%) - At 204.8 W/m², this panel generates 15.4 W/m² less per unit area than \*\*TOPCon 400-450W\*\* median (220.2 W/m²) - Temperature coefficient of -0.34%/°C is 0.05pp worse than \*\*TOPCon 400-450W\*\* median (-0.29%/°C) - higher losses in summer heat - At 21.0 kg, weight matches the \*\*TOPCon 400-450W\*\* median - In the top 81% for efficiency among all TOPCon panels ## Questions ### Is the Suntech Ultra V mini series still available for purchase? The Ultra V mini series has been discontinued by the manufacturer and replaced with newer product lines. This means availability is now limited to remaining distributor stock. It's worth checking current inventory with your supplier before planning a larger installation, since additional panels may not be available later to expand an existing system. ### What is the maximum power of the Suntech Ultra V mini module and how many panels are needed for a typical system? The module reaches a maximum power of 415 Wp thanks to TOPCon cells and half-cut technology. For a typical 5 kWp installation, roughly 12 panels are needed. Thanks to its high power density per square meter, this module fits more kilowatts on limited roof space than older PERC-based designs. ### What warranty comes with the Suntech Ultra V mini panels? The manufacturer provides a 12-year product warranty along with a 25-year power performance warranty. As a Tier 1 manufacturer based in China, Suntech offers service support in line with international industry standards, though the series' discontinuation is worth considering when planning future replacement of individual panels. ### What is TOPCon technology in the Ultra V mini panels, and is it better than PERC? TOPCon is an n-type cell technology that reduces recombination losses and delivers higher conversion efficiency than older PERC cells. In practice, this means higher energy output from the same panel area and better temperature performance, resulting in higher energy yields on hot days compared to conventional p-type modules. ### Are the Suntech Ultra V mini panels suitable for small pitched roofs? Yes, the Ultra V mini series was specifically designed for limited roof space. Compact dimensions combined with a high 415 Wp output help maximize energy production even on small roof sections. The module's low weight makes transport and installation on typical pitched roof structures easier, without overloading the roof truss. ### Is the Suntech Ultra V mini a bifacial panel? No, this specific version of the Ultra V mini series is a monofacial module, meaning it does not capture reflected light on its rear side. Suntech offers a separate Ultra V Pro mini version with bifacial technology, but this series focuses on maximizing front-side power output while keeping a lower weight and simpler construction. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/STP395-415S-C54-Umhb_EN-573cbe700eb5.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [Luxor Solar LX-440M/182-108+GG](https://comparepv.com/panel/luxor-solar-lx-440m-182-108-gg) | 440 W | Cooler, +2.6 pp, +5 yr warranty | | [Just Solar JST-EDMH-(445-465)W-TD (450W class)](https://comparepv.com/panel/just-solar-jst-edmh-445-465-w-td-450w-class) | 450 W | +50 W, +2.6 pp, +5 yr warranty | | [Q-SUN Solar QNN182-HG450-54](https://comparepv.com/panel/qn-solar-pv-limited-qnn182-hg450-54) | 450 W | +50 W, cooler, +2.5 pp | | [Huayao HY440-N108BDD](https://comparepv.com/panel/huayao-hy440-n108bdd) | 450 W | +50 W, +2.5 pp, +5 yr warranty | | [BYD NLBK-27-450](https://comparepv.com/panel/byd-nlbk-27-450) | 450 W | +50 W, +2.5 pp, +5 yr warranty | | [Renesola RS41-450NBG-E3](https://comparepv.com/panel/renesola-rs41-450nbg-e3) | 450 W | +50 W, cooler, +2.5 pp | | [Suntech STP390S-C54/Umh](https://comparepv.com/panel/suntech-stp390s-c54-umh) | 390 W | Hotter, heavier, -0.6 pp | | [Suntech STP395S-C54/Umhm](https://comparepv.com/panel/wuxi-suntech-power-co-ltd-suntech-stp395s-c54-umhm) | 395 W | -0.3 pp | | [Suntech STP395S-C54/Umh](https://comparepv.com/panel/suntech-stp395s-c54-umh) | 395 W | Hotter, heavier, -0.3 pp | | [Suntech STP400S-C54/Umh](https://comparepv.com/panel/suntech-stp400s-c54-umh) | 400 W | Hotter, heavier | | [Suntech STP405S-C54/Umhm](https://comparepv.com/panel/wuxi-suntech-power-co-ltd-suntech-stp405s-c54-umhm) | 405 W | Very close match | | [Suntech STP405S-C54/Umh](https://comparepv.com/panel/suntech-stp405s-c54-umh) | 405 W | Hotter, heavier | | [Longi Solar LR7-54HJD-510M](https://comparepv.com/panel/longi-lr7-54hjd-510m) | 510 W | +110 W, cooler, +4.5 pp | | [AIKO AIKO-A495-MCE54Mw](https://comparepv.com/panel/aiko-aiko-a495-mce54mw) | 495 W | +95 W, cooler, +4.3 pp | | [Longi Solar LR7-54HJD-505M](https://comparepv.com/panel/longi-lr7-54hjd-505m) | 505 W | +105 W, cooler, +4.2 pp | | [WINAICO WST-505BKX54-A2](https://comparepv.com/panel/winaico-wst-505bkx54-a2) | 505 W | +105 W, cooler, +4.2 pp | --- Source: https://comparepv.com/panel/wuxi-suntech-power-co-ltd-stp400s-c54-umhb 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.