--- title: "Suntech STP585S-C78/Pmh+ Solar Panel: Specs & Datasheet | ComparePV" description: "Suntech STP585S-C78/Pmh+ solar panel. Specs: 20.90% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/wuxi-suntech-power-co-ltd-stp585s-c78-pmh" image: "https://comparepv.com/og/panel/wuxi-suntech-power-co-ltd-stp585s-c78-pmh.png" updated: 2026-09-11 --- # Suntech STP585S-C78/Pmh+ Middle of its segment, modest efficiency 1,022 panels in the segment TOPCon 550-600 W ## Identity - **Manufacturer:** Suntech - **Model:** STP585S-C78/Pmh+ - **Series:** Ultra V Plus - **Rated power:** 585 W - **Cell technology:** TOPCon - **Bifacial:** yes ## How it compares Compared against segment TOPCon 550-600 W (1022 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 585 W | 580 W | Typical | | | Module efficiency | 20.90% | 22.44% | Weak - bottom 2% | 10,148 | | Power density | 209.3 | 224.4 | Weak - bottom 2% | 10,074 | | Temperature coefficient | -0.340 | -0.290 | Weak - bottom 5% | 8,846 | | Weight (kg) | 35.1 kg | 31.2 kg | Weak - bottom 3% | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 20.90% | 22.44% | Weak - bottom 2% | 10,148 | | Power density | 209.3 | 224.4 | Weak - bottom 2% | 10,074 | | Temperature coefficient | -0.340 | -0.290 | Weak - bottom 5% | 8,846 | | Weight per kWp | 60.0 | 53.8 | Weak - bottom 3% | 12,457 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Watch out for - **20.90% module efficiency** - Bottom 2% of the TOPCon 550-600 W segment, against a median of 22.44%. Ranked 10,148th in the whole database. - **209.3 watts per square metre** - Bottom 2% of the TOPCon 550-600 W segment, against a median of 224.4. Ranked 10,074th in the whole database. - **60.0 kg per kWp** - Bottom 3% of the TOPCon 550-600 W segment, against a median of 53.8. Ranked 12,457th in the whole database. - **Best for:** Commercial, utility-scale and shaded-installations. - **Not ideal for:** Tight roof space, roofs where every square metre has to count and weight-limited structures. ## Specification ### Electrical - **Rated power (Pmax):** 585 W - **Efficiency:** 20.90 % - **Voltage at Pmax (Vmp):** 45.18 V - **Current at Pmax (Imp):** 12.95 A - **Open-circuit voltage (Voc):** 53.61 V - **Short-circuit current (Isc):** 13.85 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:** 156 - **Bifacial:** yes - **Bifacial gain:** 25.00 ### Physical - **Length:** 2465 mm - **Width:** 1134 mm - **Thickness:** 35 mm - **Weight:** 35.1 kg - **Area:** 2.80 m2 - **Power density:** 209.3 Wp/m2 ### Warranty and degradation - **Product warranty:** 15 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:** 497 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 10148 of 14129 | | Power density | 10074 of 14129 | | Temperature coefficient | 8846 of 14129 | | Weight | 12457 of 14129 | | Warranty | 21 of 14129 | ## About this series Ultra V Plus is a series of **bifacial dual-sided modules** designed for investors who want to maximize energy yield from every square meter of roof or ground-mounted installation space. The panel uses **monocrystalline half-cut cells** arranged in a 6x26 layout, which reduces power losses from partial shading and improves reliability under demanding irradiance conditions. Thanks to multi-busbar technology and Suntech's proprietary current-sorting process, the module effectively eliminates electrical mismatch between cells, translating into a real increase in energy output from the system. The rear-side design allows for additional energy capture from light reflected off the ground, making the series particularly attractive for installations on bright surfaces, flat roofs, or ground-mount systems. The panels stand out with a **low power temperature coefficient**, losing less performance on hot days compared to competing solutions, along with strong output in low-light conditions such as mornings or overcast weather. The module has passed extended wind and snow load testing, confirming its durability in demanding climate conditions. The series is backed by a **30-year linear warranty** and low annual power degradation, making it a solid choice for both residential installations and large-scale commercial solar farm projects. ## Notable figures - Module efficiency of 20.9% is 1.5pp below average for \*\*TOPCon 550-600W\*\* panels (median: 22.4%) - At 209.3 W/m², this panel generates 15.1 W/m² less per unit area than \*\*TOPCon 550-600W\*\* median (224.4 W/m²) - -0.34%/°C temperature coefficient - 0.05pp worse than \*\*TOPCon 550-600W\*\* median (-0.29%/°C), expect higher hot weather losses - Weight of 35.1 kg is 3.9 kg above \*\*TOPCon 550-600W\*\* median (31.2 kg) - verify structural support - Bifacial design (70% factor) captures reflected light - adds 4-10% yield on ground-mount or white roof ## Questions ### What is the maximum power output of the Suntech Ultra V Plus panel? Modules in the Ultra V Plus series reach a maximum power of up to 605 Wp. This high output comes from monocrystalline half-cut TOPCon cells, which deliver higher conversion efficiency than older PERC-based designs while keeping module dimensions comparable to standard panels. ### What warranty does Suntech offer on the Ultra V Plus series? The manufacturer provides a 15-year product warranty and a 30-year linear power warranty. This means that after 30 years of operation the module is guaranteed to still deliver a minimum specified power output, which is standard for modern TOPCon-based panels. ### Is the Suntech Ultra V Plus a bifacial (dual-sided) panel? No, this version of the Ultra V Plus is a monofacial module. It uses TOPCon technology with half-cut cells, but energy is generated only from the front side, unlike the bifacial variants in Suntech's Ultra V Pro lineup, where the rear side also contributes to power output. ### What is TOPCon technology and how does it differ from PERC? TOPCon (Tunnel Oxide Passivated Contact) is an n-type cell technology with an additional passivation layer that reduces carrier recombination and increases conversion efficiency compared to older p-type PERC cells. In practice this results in higher module power, a lower temperature coefficient, and slower annual power degradation over time. ### Is the Suntech Ultra V Plus suitable for large commercial and utility-scale solar farms? Yes, the high unit power of up to 605 Wp combined with a large cell format makes the series well suited to commercial rooftop installations as well as ground-mount systems and utility-scale solar farms, where maximizing energy yield per unit of land area matters most. ### Is Suntech a Tier 1 manufacturer, and is it worth buying panels from a Chinese producer? Suntech is classified as a Tier 1 manufacturer, indicating financial stability, in-house production lines, and a long-standing presence in the global market. The company is headquartered in China, but its modules are certified to European (IEC) standards and widely deployed across Poland and other EU markets, supporting warranty service availability. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/STP585-605S-C78-Pmh_EN-c0652731fee5.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [Longi Solar LR7-60HVH-560M](https://comparepv.com/panel/longi-lr7-60hvh-560m) | 560 W | Cooler, lighter, +3.9 pp | | [Longi Solar LR7-60HVH-555M](https://comparepv.com/panel/longi-lr7-60hvh-555m) | 555 W | Cooler, lighter, +3.7 pp | | [AIKO AIKO-A635-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a635-mae72mw) | 635 W | Cooler, lighter, +3.7 pp | | [AIKO AIKO-A630-MAH72Dw](https://comparepv.com/panel/aiko-aiko-a630-mah72dw) | 630 W | +45 W, cooler, +3.5 pp | | [Longi Solar LR7-60HVHL-550M](https://comparepv.com/panel/longi-lr7-60hvhl-550m) | 550 W | Cooler, 19 kg lighter, +3.5 pp | | [Suntech STP570S-C78/Pmh+](https://comparepv.com/panel/suntech-stp570s-c78-pmh) | 570 W | -15 W, -0.5 pp | | [Suntech STP570S-C78/Pmhg](https://comparepv.com/panel/suntech-stp570s-c78-pmhg) | 570 W | Lighter, -0.5 pp, -5 yr warranty | | [Suntech STP575S-C78/Pmh+](https://comparepv.com/panel/suntech-stp575s-c78-pmh) | 575 W | -10 W, -0.3 pp | | [Suntech STP575S-C78/Pmhg](https://comparepv.com/panel/suntech-stp575s-c78-pmhg) | 575 W | Hotter, lighter, -5 yr warranty | | [Suntech STP580S-C78/Pmh+](https://comparepv.com/panel/suntech-stp580s-c78-pmh) | 580 W | Very close match | | [Suntech STP580S-C78/Pmhg](https://comparepv.com/panel/suntech-stp580s-c78-pmhg) | 580 W | Hotter, lighter, -5 yr warranty | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +95 W, cooler, +4.3 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +90 W, cooler, +4.1 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +115 W, cooler, +4.1 pp | | [WINAICO WST-675BKX72-A2](https://comparepv.com/panel/winaico-wst-675bkx72-a2) | 675 W | +90 W, cooler, +4.1 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +110 W, cooler, +4.0 pp | --- Source: https://comparepv.com/panel/wuxi-suntech-power-co-ltd-stp585s-c78-pmh 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.