--- title: "Trina Solar TSM-NEG9R.28 455W vs Trina Solar TSM-NEG21C.20 725W - Solar Panel Comparison | ComparePV" description: "Compare Trina Solar TSM-NEG9R.28 455W vs Trina Solar TSM-NEG21C.20 725W side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/trina-solar-co-ltd-tsm-neg9r-28-455w-1/trina-solar-tsm-neg21c-20-725w" image: "https://comparepv.com/og/compare/panels/trina-solar-co-ltd-tsm-neg9r-28-455w-1/trina-solar-tsm-neg21c-20-725w.png" updated: 2026-09-11 --- # Trina Solar TSM-NEG9R.28 455W vs Trina Solar TSM-NEG21C.20 725W 14 differences, and they point both ways The largest is rated power: 270 W more power. 5 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Trina Solar TSM-NEG9R.28 455W](https://comparepv.com/panel/trina-solar-co-ltd-tsm-neg9r-28-455w-1) | [Trina Solar TSM-NEG21C.20 725W](https://comparepv.com/panel/trina-solar-tsm-neg21c-20-725w) | | Manufacturer | Trina Solar | Trina Solar | | Power | 455 Wp | 725 Wp | | Efficiency | 22.80 % | 23.30 % | | Technology | TOPCon | TOPCon | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | NEG9R.28 455W | NEG21C.20 725W | Difference | | --- | --- | --- | --- | | Rated power | 455 Wp | 725 Wp | +270 W for NEG21C.20 725W | | Module efficiency | 22.80 % | 23.30 % | +0.50 pp for NEG21C.20 725W | | Weight | 21.0 kg | 38.3 kg | -17.3 kg for NEG9R.28 455W | | Weight per kWp | 46.2 kg/kWp | 52.8 kg/kWp | -6.7 kg/kWp for NEG9R.28 455W | | Product warranty | 15 yrs | 12 yrs | +3 yrs for NEG9R.28 455W | | Short-circuit current | 10.77 A | 18.54 A | 7.77 A apart | | Module area | 1.998 m² | 3.106 m² | 1.108 m² apart | | Open-circuit voltage | 53.40 V | 49.60 V | 3.80 V apart | | Power density | 227.7 Wp/m² | 233.4 Wp/m² | +5.7 Wp/m² for NEG21C.20 725W | | Current at max power | 10.11 A | 17.47 A | 7.36 A apart | | Cell count | 144 | 132 | 12 cells apart | | Voltage at max power | 45.00 V | 41.50 V | 3.50 V apart | | Bifacial | No | Yes | No vs Yes | | Dimensions | 1762x1134x30 mm | 2384x1303x33 mm | 1762x1134x30 mm vs 2384x1303x33 mm | ## Every compared parameter | Parameter | NEG9R.28 455W | NEG21C.20 725W | | --- | --- | --- | | Rated power | 455 Wp | 725 Wp | | Module efficiency | 22.80 % | 23.30 % | | Power density | 227.7 Wp/m² | 233.4 Wp/m² | | Open-circuit voltage | 53.40 V | 49.60 V | | Voltage at max power | 45.00 V | 41.50 V | | Short-circuit current | 10.77 A | 18.54 A | | Current at max power | 10.11 A | 17.47 A | | Temperature coefficient | -0.290 %/°C | -0.290 %/°C | | Dimensions | 1762x1134x30 mm | 2384x1303x33 mm | | Module area | 1.998 m² | 3.106 m² | | Weight | 21.0 kg | 38.3 kg | | Weight per kWp | 46.2 kg/kWp | 52.8 kg/kWp | | Product warranty | 15 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 | 144 | 132 | | Bifacial | No | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year Same temp coeff. for both panels (-0.290 %/°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, NEG9R.28 455W:** 15,266 kWh - **Cumulative output, NEG21C.20 725W:** 24,325 kWh - **Gap:** 9,059 kWh ## Output when hot | Condition | Cell temperature | NEG9R.28 455W | NEG21C.20 725W | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 455 W | 725 W | 100.0% of rated power | | Cool, bright day | 40 °C | 435 W | 693 W | 95.7% of rated power | | Typical summer roof | 55 °C | 415 W | 662 W | 91.3% of rated power | | Hot roof | 70 °C | 396 W | 630 W | 87.0% of rated power | ## Against the whole database | Measure | NEG9R.28 455W | NEG21C.20 725W | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #2,769 | #1,057 | 14,129 | NEG21C.20 725W leads by 1,712 places | | Power density | #2,943 | #974 | 14,129 | NEG21C.20 725W leads by 1,969 places | | Heat behaviour | #2,220 | #2,220 | 14,129 | Tied - the same position in the database | | Weight | #1,016 | #6,570 | 14,129 | NEG9R.28 455W leads by 5,554 places | | Warranty | #21 | #21 | 14,129 | Tied - the same position in the database | | Overall | #7,793 | #431 | 14,129 | NEG21C.20 725W leads by 7,362 places | ## Questions ### Which panel is better: Trina Solar TSM-NEG9R.28 455W or Trina Solar TSM-NEG21C.20 725W? According to our database: **Trina Solar TSM-NEG21C.20 **725 W**** has higher module efficiency (**23.30%** vs **22.80%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Trina Solar TSM-NEG9R.28 455W and Trina Solar TSM-NEG21C.20 725W? **Trina Solar TSM-NEG9R.28 **455 W**** has a module efficiency of **22.80%**, while **Trina Solar TSM-NEG21C.20 **725 W**** is **23.30%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Trina Solar TSM-NEG9R.28 455W use vs Trina Solar TSM-NEG21C.20 725W? **Trina Solar TSM-NEG9R.28 **455 W**** uses **TOPCon** cells; **Trina Solar TSM-NEG21C.20 **725 W**** 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 Trina Solar TSM-NEG9R.28 455W and Trina Solar TSM-NEG21C.20 725W? **Trina Solar TSM-NEG9R.28 **455 W**** has a **30 years** power warranty; **Trina Solar TSM-NEG21C.20 **725 W**** 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 Trina Solar TSM-NEG9R.28 455W and Trina Solar TSM-NEG21C.20 725W bifacial panels? **Trina Solar TSM-NEG21C.20 **725 W**** is bifacial (captures light from both faces); **Trina Solar TSM-NEG9R.28 **455 W**** is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath. ## Related comparisons - [Trina Solar TSM-NEG9R.28 455W vs Trina Solar TSM-470NED9R.28](https://comparepv.com/compare/trina-solar-co-ltd-tsm-neg9r-28-455w-1/trina-solar-tsm-470ned9r-28) - 8 differences, the largest is module efficiency - [Trina Solar TSM-NEG9R.28 455W vs Trina Solar TSM-465NED9R.28](https://comparepv.com/compare/trina-solar-co-ltd-tsm-neg9r-28-455w-1/trina-solar-tsm-465ned9r-28) - 6 differences, the largest is module efficiency - [Trina Solar TSM-NEG9R.28 455W vs Trina Solar TSM-NEG9R.28-460](https://comparepv.com/compare/trina-solar-co-ltd-tsm-neg9r-28-455w-1/trina-solar-co-ltd-tsm-neg9r-28-460-1) - One difference: module efficiency - [Trina Solar TSM-NEG9R.28 455W vs Trina Solar TSM-NEG9R.28 460W](https://comparepv.com/compare/trina-solar-co-ltd-tsm-neg9r-28-455w-1/trina-solar-co-ltd-tsm-neg9r-28-460w-1) - One difference: module efficiency - [Trina Solar TSM-NEG9R.28 455W vs Trina Solar TSM-460NEG9R.28](https://comparepv.com/compare/trina-solar-co-ltd-tsm-neg9r-28-455w-1/trina-solar-tsm-460neg9r-28) - 3 differences, the largest is product warranty - [Trina Solar TSM-NEG9R.28 455W vs Trina Solar TSM-460 NEG9R.28](https://comparepv.com/compare/trina-solar-co-ltd-tsm-neg9r-28-455w-1/trina-solar-tsm-460-neg9r-28) - 3 differences, the largest is product warranty --- Source: https://comparepv.com/compare/trina-solar-co-ltd-tsm-neg9r-28-455w-1/trina-solar-tsm-neg21c-20-725w 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.