--- title: "Suntech STP670S-D66/Wmh vs Suntech STP675S-D66/Wmh - Solar Panel Comparison | ComparePV" description: "Compare Suntech STP670S-D66/Wmh vs Suntech STP675S-D66/Wmh side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/suntech-stp670s-d66-wmh/suntech-stp675s-d66-wmh" updated: 2026-09-11 --- # Suntech STP670S-D66/Wmh vs Suntech STP675S-D66/Wmh Identical on every published parameter All 19 comparable parameters agree. Two records this alike are usually one panel sold under two names, or two bins of the same production line - decide on price and on who you would rather buy from. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Suntech STP670S-D66/Wmh](https://comparepv.com/panel/suntech-stp670s-d66-wmh) | [Suntech STP675S-D66/Wmh](https://comparepv.com/panel/suntech-stp675s-d66-wmh) | | Manufacturer | Suntech | Suntech | | Power | 670 Wp | 675 Wp | | Efficiency | 21.60 % | 21.70 % | | Technology | TOPCon | TOPCon | ## Every compared parameter | Parameter | STP670S-D66/Wmh | STP675S-D66/Wmh | | --- | --- | --- | | Rated power | 670 Wp | 675 Wp | | Module efficiency | 21.60 % | 21.70 % | | Power density | 215.7 Wp/m² | 217.3 Wp/m² | | Open-circuit voltage | 46.45 V | 46.65 V | | Voltage at max power | 38.45 V | 38.65 V | | Short-circuit current | 18.43 A | 18.47 A | | Current at max power | 17.43 A | 17.46 A | | Temperature coefficient | -0.340 %/°C | -0.340 %/°C | | Dimensions | 2384x1303x35 mm | 2384x1303x35 mm | | Module area | 3.106 m² | 3.106 m² | | Weight | 33.5 kg | 33.5 kg | | Weight per kWp | 50.0 kg/kWp | 49.6 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 25 yrs | 25 yrs | | Annual degradation | 0.55 %/yr | 0.55 %/yr | | Cell technology | TOPCon | TOPCon | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 132 | | Bifacial | No | No | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year Same temp coeff. for both panels (-0.340 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other. - **Cumulative output, STP670S-D66/Wmh:** 21,714 kWh - **Cumulative output, STP675S-D66/Wmh:** 21,876 kWh - **Gap:** 162 kWh ## Output when hot | Condition | Cell temperature | STP670S-D66/Wmh | STP675S-D66/Wmh | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 670 W | 675 W | 100.0% of rated power | | Cool, bright day | 40 °C | 636 W | 641 W | 94.9% of rated power | | Typical summer roof | 55 °C | 602 W | 606 W | 89.8% of rated power | | Hot roof | 70 °C | 567 W | 572 W | 84.7% of rated power | ## Against the whole database | Measure | STP670S-D66/Wmh | STP675S-D66/Wmh | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #7,652 | #7,421 | 14,005 | STP675S-D66/Wmh leads by 231 places | | Power density | #7,644 | #7,349 | 14,005 | STP675S-D66/Wmh leads by 295 places | | Heat behaviour | #8,778 | #8,778 | 14,005 | Tied - the same position in the database | | Weight | #3,317 | #3,176 | 14,005 | STP675S-D66/Wmh leads by 141 places | | Warranty | #9,798 | #9,798 | 14,005 | Tied - the same position in the database | | Overall | #3,364 | #3,026 | 14,005 | STP675S-D66/Wmh leads by 338 places | ## Questions ### Which panel is better: Suntech STP670S-D66/Wmh or Suntech STP675S-D66/Wmh? According to our database: **Suntech STP675S-D66/Wmh** has higher module efficiency (**21.70%** vs **21.60%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Suntech STP670S-D66/Wmh and Suntech STP675S-D66/Wmh? **Suntech STP670S-D66/Wmh** has a module efficiency of **21.60%**, while **Suntech STP675S-D66/Wmh** is **21.70%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Suntech STP670S-D66/Wmh use vs Suntech STP675S-D66/Wmh? **Suntech STP670S-D66/Wmh** uses **TOPCon** cells; **Suntech STP675S-D66/Wmh** uses **TOPCon**. Modern **n-type** technologies (**TOPCon**, **HJT**, BC) typically deliver higher efficiency and lower degradation compared to older **PERC** (p-type) cells. ### What is the warranty on Suntech STP670S-D66/Wmh and Suntech STP675S-D66/Wmh? **Suntech STP670S-D66/Wmh** has a **25 years** power warranty; **Suntech STP675S-D66/Wmh** has a **25 years** power warranty. The power warranty guarantees a minimum percentage of rated output at the end of the warranty period (typically 80**-87%**). Product (materials) warranties are usually shorter. ## Related comparisons - [Suntech STP670S-D66/Wmh vs Suntech STP700S-D66-Nsh+](https://comparepv.com/compare/suntech-stp670s-d66-wmh/suntech-stp700s-d66-nsh) - 12 differences, the largest is module efficiency - [Suntech STP670S-D66/Wmh vs Suntech STP670S-D66/Pmh+](https://comparepv.com/compare/suntech-stp670s-d66-wmh/wuxi-suntech-power-co-ltd-stp670s-d66-pmh) - 6 differences, the largest is performance warranty - [Suntech STP670S-D66/Wmh vs Suntech STP665S-D66/Wmh](https://comparepv.com/compare/suntech-stp670s-d66-wmh/suntech-stp665s-d66-wmh) - One difference: module efficiency - [Suntech STP670S-D66/Wmh vs Suntech STP665S-D66/Pmh+](https://comparepv.com/compare/suntech-stp670s-d66-wmh/wuxi-suntech-power-co-ltd-stp665s-d66-pmh) - 7 differences, the largest is performance warranty - [Suntech STP670S-D66/Wmh vs Suntech STP660S-D66/Wmh](https://comparepv.com/compare/suntech-stp670s-d66-wmh/suntech-stp660s-d66-wmh) - 3 differences, the largest is module efficiency - [Suntech STP670S-D66/Wmh vs Suntech STP660S-D66/Pmh+](https://comparepv.com/compare/suntech-stp670s-d66-wmh/wuxi-suntech-power-co-ltd-stp660s-d66-pmh) - 9 differences, the largest is performance warranty --- Source: https://comparepv.com/compare/suntech-stp670s-d66-wmh/suntech-stp675s-d66-wmh Not in this file, on the page: the thirty-year yield curve year by year at a cell temperature you pick and a written summary generated on request.