--- title: "Suntech STP505S-H54-Nfb+ vs Suntech STP705S-D66-Nsh+ - Solar Panel Comparison | ComparePV" description: "Compare Suntech STP505S-H54-Nfb+ vs Suntech STP705S-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-stp505s-h54-nfb/suntech-stp705s-d66-nsh" updated: 2026-09-11 --- # Suntech STP505S-H54-Nfb+ vs Suntech STP705S-D66-Nsh+ STP505S-H54-Nfb+ leads on the differences that matter The largest is rated power: 200 W more power. 6 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Suntech STP505S-H54-Nfb+](https://comparepv.com/panel/suntech-stp505s-h54-nfb) | [Suntech STP705S-D66-Nsh+](https://comparepv.com/panel/suntech-stp705s-d66-nsh) | | Manufacturer | Suntech | Suntech | | Power | 505 Wp | 705 Wp | | Efficiency | 22.70 % | 22.70 % | | Technology | TOPCon | TOPCon | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | STP505S-H54-Nfb+ | STP705S-D66-Nsh+ | Difference | | --- | --- | --- | --- | | Rated power | 505 Wp | 705 Wp | +200 W for STP705S-D66-Nsh+ | | Weight | 23.5 kg | 38.5 kg | -15.0 kg for STP505S-H54-Nfb+ | | Weight per kWp | 46.5 kg/kWp | 54.6 kg/kWp | -8.1 kg/kWp for STP505S-H54-Nfb+ | | Product warranty | 25 yrs | 12 yrs | +13 yrs for STP505S-H54-Nfb+ | | Open-circuit voltage | 40.55 V | 48.57 V | 8.02 V apart | | Short-circuit current | 15.68 A | 18.43 A | 2.75 A apart | | Module area | 2.224 m² | 3.106 m² | 0.883 m² apart | | Temperature coefficient | -0.280 %/°C | -0.290 %/°C | +0.010 %/°C for STP505S-H54-Nfb+ | | Voltage at max power | 34.17 V | 40.31 V | 6.14 V apart | | Current at max power | 14.78 A | 17.49 A | 2.71 A apart | | Cell count | 108 | 132 | 24 cells apart | | Bifacial | No | Yes | No vs Yes | | Dimensions | 1961x1134x30 mm | 2384x1303x33 mm | 1961x1134x30 mm vs 2384x1303x33 mm | ## Every compared parameter | Parameter | STP505S-H54-Nfb+ | STP705S-D66-Nsh+ | | --- | --- | --- | | Rated power | 505 Wp | 705 Wp | | Module efficiency | 22.70 % | 22.70 % | | Power density | 227.1 Wp/m² | 227.0 Wp/m² | | Open-circuit voltage | 40.55 V | 48.57 V | | Voltage at max power | 34.17 V | 40.31 V | | Short-circuit current | 15.68 A | 18.43 A | | Current at max power | 14.78 A | 17.49 A | | Temperature coefficient | -0.280 %/°C | -0.290 %/°C | | Dimensions | 1961x1134x30 mm | 2384x1303x33 mm | | Module area | 2.224 m² | 3.106 m² | | Weight | 23.5 kg | 38.5 kg | | Weight per kWp | 46.5 kg/kWp | 54.6 kg/kWp | | Product warranty | 25 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.40 %/yr | | Cell technology | TOPCon | TOPCon | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 108 | 132 | | Bifacial | No | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year - **Cumulative output, STP505S-H54-Nfb+:** 16,944 kWh - **Cumulative output, STP705S-D66-Nsh+:** 23,654 kWh - **Gap:** 6,710 kWh ## Output when hot | Condition | Cell temperature | STP505S-H54-Nfb+ | STP705S-D66-Nsh+ | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 505 W | 705 W | 100.0% of rated power | | Cool, bright day | 40 °C | 484 W | 674 W | 95.7% of rated power | | Typical summer roof | 55 °C | 463 W | 644 W | 91.3% of rated power | | Hot roof | 70 °C | 441 W | 613 W | 87.0% of rated power | ## Against the whole database | Measure | STP505S-H54-Nfb+ | STP705S-D66-Nsh+ | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #3,307 | #3,307 | 14,005 | Tied - the same position in the database | | Power density | #3,312 | #3,361 | 14,005 | STP505S-H54-Nfb+ leads by 49 places | | Heat behaviour | #1,309 | #2,165 | 14,005 | STP505S-H54-Nfb+ leads by 856 places | | Weight | #1,199 | #8,959 | 14,005 | STP505S-H54-Nfb+ leads by 7,760 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #4,015 | #1,037 | 14,005 | STP705S-D66-Nsh+ leads by 2,978 places | ## Questions ### Which panel is better: Suntech STP505S-H54-Nfb+ or Suntech STP705S-D66-Nsh+? According to our database: **Suntech STP505S-H54-Nfb+** tolerates heat better (temp coeff **-0.280%/°C** vs **-0.290%/°C**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Suntech STP505S-H54-Nfb+ and Suntech STP705S-D66-Nsh+? **Suntech STP505S-H54-Nfb+** has a module efficiency of **22.70%**, while **Suntech STP705S-D66-Nsh+** is **22.70%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Suntech STP505S-H54-Nfb+ use vs Suntech STP705S-D66-Nsh+? **Suntech STP505S-H54-Nfb+** uses **TOPCon** cells; **Suntech STP705S-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 STP505S-H54-Nfb+ and Suntech STP705S-D66-Nsh+? **Suntech STP505S-H54-Nfb+** has a **30 years** power warranty; **Suntech STP705S-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 STP505S-H54-Nfb+ and Suntech STP705S-D66-Nsh+ bifacial panels? **Suntech STP705S-D66-Nsh+** is bifacial (captures light from both faces); **Suntech STP505S-H54-Nfb+** is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath. ## Related comparisons - [Suntech STP505S-H54-Nfb+ vs Suntech STP735S-D66-Nsh+](https://comparepv.com/compare/suntech-stp505s-h54-nfb/suntech-stp735s-d66-nsh) - 14 differences, the largest is module efficiency - [Suntech STP505S-H54-Nfb+ vs Suntech STP730S-D66-Nsh+](https://comparepv.com/compare/suntech-stp505s-h54-nfb/suntech-stp730s-d66-nsh) - 14 differences, the largest is module efficiency - [Suntech STP505S-H54-Nfb+ vs Suntech STP725S-D66-Nsh+](https://comparepv.com/compare/suntech-stp505s-h54-nfb/suntech-stp725s-d66-nsh) - 14 differences, the largest is rated power - [Suntech STP505S-H54-Nfb+ vs Suntech STP720S-D66-Nsh+](https://comparepv.com/compare/suntech-stp505s-h54-nfb/suntech-stp720s-d66-nsh) - 14 differences, the largest is rated power - [Suntech STP505S-H54-Nfb+ vs Suntech STP715S-D66-Nsh+](https://comparepv.com/compare/suntech-stp505s-h54-nfb/suntech-stp715s-d66-nsh) - 14 differences, the largest is rated power - [Suntech STP505S-H54-Nfb+ vs Suntech STP710S-D66-Nsh+](https://comparepv.com/compare/suntech-stp505s-h54-nfb/suntech-stp710s-d66-nsh) - 13 differences, the largest is rated power --- Source: https://comparepv.com/compare/suntech-stp505s-h54-nfb/suntech-stp705s-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.