--- title: "Suntech STP-NT11/66QGDF-665 vs Suntech STP730S-D66-Nsh+ - Solar Panel Comparison | ComparePV" description: "Compare Suntech STP-NT11/66QGDF-665 vs Suntech STP730S-D66-Nsh+ side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/suntech-stp-nt11-66qgdf-665/suntech-stp730s-d66-nsh" updated: 2026-09-11 --- # Suntech STP-NT11/66QGDF-665 vs Suntech STP730S-D66-Nsh+ STP-NT11/66QGDF-665 leads on the differences that matter The largest is module efficiency: 1.10 pp more efficient. 8 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Suntech STP-NT11/66QGDF-665](https://comparepv.com/panel/suntech-stp-nt11-66qgdf-665) | [Suntech STP730S-D66-Nsh+](https://comparepv.com/panel/suntech-stp730s-d66-nsh) | | Manufacturer | Suntech | Suntech | | Power | 665 Wp | 730 Wp | | Efficiency | 24.60 % | 23.50 % | | Technology | TOPCon | TOPCon | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | STP-NT11/66QGDF-665 | STP730S-D66-Nsh+ | Difference | | --- | --- | --- | --- | | Module efficiency | 24.60 % | 23.50 % | +1.10 pp for STP-NT11/66QGDF-665 | | Rated power | 665 Wp | 730 Wp | +65 W for STP730S-D66-Nsh+ | | Power density | 246.2 Wp/m² | 235.0 Wp/m² | +11.2 Wp/m² for STP-NT11/66QGDF-665 | | Weight | 33.1 kg | 37.5 kg | -4.4 kg for STP-NT11/66QGDF-665 | | Temperature coefficient | -0.260 %/°C | -0.280 %/°C | +0.020 %/°C for STP-NT11/66QGDF-665 | | Module area | 2.701 m² | 3.106 m² | 0.405 m² apart | | Short-circuit current | 16.57 A | 18.54 A | 1.97 A apart | | Annual degradation | 0.35 %/yr | 0.40 %/yr | -0.05 %/yr for STP-NT11/66QGDF-665 | | Cell count | 264 | 132 | 132 cells apart | | Current at max power | 15.76 A | 17.70 A | 1.94 A apart | | Dimensions | 2382x1134x30 mm | 2384x1303x33 mm | 2382x1134x30 mm vs 2384x1303x33 mm | ## Every compared parameter | Parameter | STP-NT11/66QGDF-665 | STP730S-D66-Nsh+ | | --- | --- | --- | | Rated power | 665 Wp | 730 Wp | | Module efficiency | 24.60 % | 23.50 % | | Power density | 246.2 Wp/m² | 235.0 Wp/m² | | Open-circuit voltage | 50.45 V | 49.66 V | | Voltage at max power | 42.21 V | 41.27 V | | Short-circuit current | 16.57 A | 18.54 A | | Current at max power | 15.76 A | 17.70 A | | Temperature coefficient | -0.260 %/°C | -0.280 %/°C | | Dimensions | 2382x1134x30 mm | 2384x1303x33 mm | | Module area | 2.701 m² | 3.106 m² | | Weight | 33.1 kg | 37.5 kg | | Weight per kWp | 49.8 kg/kWp | 51.4 kg/kWp | | Product warranty | 15 yrs | 15 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.35 %/yr | 0.40 %/yr | | Cell technology | TOPCon | TOPCon | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 264 | 132 | | Bifacial | Yes | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year - **Cumulative output, STP-NT11/66QGDF-665:** 22,486 kWh - **Cumulative output, STP730S-D66-Nsh+:** 24,493 kWh - **Gap:** 2,007 kWh ## Output when hot | Condition | Cell temperature | STP-NT11/66QGDF-665 | STP730S-D66-Nsh+ | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 665 W | 730 W | 100.0% of rated power | | Cool, bright day | 40 °C | 639 W | 699 W | 95.8% of rated power | | Typical summer roof | 55 °C | 613 W | 669 W | 91.6% of rated power | | Hot roof | 70 °C | 587 W | 638 W | 87.4% of rated power | ## Against the whole database | Measure | STP-NT11/66QGDF-665 | STP730S-D66-Nsh+ | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #51 | #716 | 14,005 | STP-NT11/66QGDF-665 leads by 665 places | | Power density | #42 | #800 | 14,005 | STP-NT11/66QGDF-665 leads by 758 places | | Heat behaviour | #511 | #1,309 | 14,005 | STP-NT11/66QGDF-665 leads by 798 places | | Weight | #3,223 | #4,748 | 14,005 | STP-NT11/66QGDF-665 leads by 1,525 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #414 | #196 | 14,005 | STP730S-D66-Nsh+ leads by 218 places | ## Questions ### Which panel is better: Suntech STP-NT11/66QGDF-665 or Suntech STP730S-D66-Nsh+? According to our database: **Suntech STP-NT11/66QGDF-665** has higher module efficiency (**24.60%** vs **23.50%**); **Suntech STP-NT11/66QGDF-665** tolerates heat better (temp coeff **-0.260%/°C** vs **-0.280%/°C**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Suntech STP-NT11/66QGDF-665 and Suntech STP730S-D66-Nsh+? **Suntech STP-NT11/66QGDF-665** has a module efficiency of **24.60%**, while **Suntech STP730S-D66-Nsh+** is **23.50%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Suntech STP-NT11/66QGDF-665 use vs Suntech STP730S-D66-Nsh+? **Suntech STP-NT11/66QGDF-665** uses **TOPCon** cells; **Suntech STP730S-D66-Nsh+** 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 STP-NT11/66QGDF-665 and Suntech STP730S-D66-Nsh+? **Suntech STP-NT11/66QGDF-665** has a **30 years** power warranty; **Suntech STP730S-D66-Nsh+** has a **30 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. ### Are Suntech STP-NT11/66QGDF-665 and Suntech STP730S-D66-Nsh+ bifacial panels? Both **Suntech STP-NT11/66QGDF-665** and **Suntech STP730S-D66-Nsh+** are bifacial - they capture reflected light from the ground, which can add 5**-15%** more annual energy on ground-mount or elevated rooftop installations with a light surface beneath. ## Related comparisons - [Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/66QGDF-670](https://comparepv.com/compare/suntech-stp-nt11-66qgdf-665/suntech-stp-nt11-66qgdf-670) - One difference: module efficiency - [Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/66QGDF-660](https://comparepv.com/compare/suntech-stp-nt11-66qgdf-665/suntech-stp-nt11-66qgdf-660) - One difference: module efficiency - [Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/66QGDF-655](https://comparepv.com/compare/suntech-stp-nt11-66qgdf-665/suntech-stp-nt11-66qgdf-655) - 3 differences, the largest is module efficiency - [Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/66QGDF-650](https://comparepv.com/compare/suntech-stp-nt11-66qgdf-665/suntech-stp-nt11-66qgdf-650) - 3 differences, the largest is module efficiency - [Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/66QGDF-645](https://comparepv.com/compare/suntech-stp-nt11-66qgdf-665/suntech-stp-nt11-66qgdf-645) - 3 differences, the largest is module efficiency - [Suntech STP-NT11/66QGDF-665 vs Suntech STP-NT11/66QGDF-640](https://comparepv.com/compare/suntech-stp-nt11-66qgdf-665/suntech-stp-nt11-66qgdf-640) - 3 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/suntech-stp-nt11-66qgdf-665/suntech-stp730s-d66-nsh 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.