--- title: "Trina Solar TSM-NEG21C.20 730 vs Trina Solar TSM-NEG21C.20Q-745 - Solar Panel Comparison | ComparePV" description: "Compare Trina Solar TSM-NEG21C.20 730 vs Trina Solar TSM-NEG21C.20Q-745 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-tsm-neg21c-20-730/trina-solar-tsm-neg21c-20q-745" updated: 2026-09-11 --- # Trina Solar TSM-NEG21C.20 730 vs Trina Solar TSM-NEG21C.20Q-745 20Q-745 leads on the differences that matter The largest is temperature coefficient: 0.030 %/°C better in heat. 13 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Trina Solar TSM-NEG21C.20 730](https://comparepv.com/panel/trina-solar-tsm-neg21c-20-730) | [Trina Solar TSM-NEG21C.20Q-745](https://comparepv.com/panel/trina-solar-tsm-neg21c-20q-745) | | Manufacturer | Trina Solar | Trina Solar | | Power | 730 Wp | 745 Wp | | Efficiency | 23.50 % | 24.00 % | | Technology | TOPCon | TOPCon | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 20 730 | 20Q-745 | Difference | | --- | --- | --- | --- | | Temperature coefficient | -0.290 %/°C | -0.260 %/°C | +0.030 %/°C for 20Q-745 | | Module efficiency | 23.50 % | 24.00 % | +0.50 pp for 20Q-745 | | Power density | 235.0 Wp/m² | 239.8 Wp/m² | +4.8 Wp/m² for 20Q-745 | | Rated power | 730 Wp | 745 Wp | +15 W for 20Q-745 | | Annual degradation | 0.40 %/yr | 0.35 %/yr | -0.05 %/yr for 20Q-745 | | Cell count | 132 | 264 | 132 cells apart | ## Every compared parameter | Parameter | 20 730 | 20Q-745 | | --- | --- | --- | | Rated power | 730 Wp | 745 Wp | | Module efficiency | 23.50 % | 24.00 % | | Power density | 235.0 Wp/m² | 239.8 Wp/m² | | Open-circuit voltage | 49.90 V | 50.30 V | | Voltage at max power | 41.70 V | 42.30 V | | Short-circuit current | 18.58 A | 18.73 A | | Current at max power | 17.51 A | 17.62 A | | Temperature coefficient | -0.290 %/°C | -0.260 %/°C | | Dimensions | 2384x1303x33 mm | 2384x1303x33 mm | | Module area | 3.106 m² | 3.106 m² | | Weight | 38.3 kg | 38.3 kg | | Weight per kWp | 52.5 kg/kWp | 51.4 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.35 %/yr | | Cell technology | TOPCon | TOPCon | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 264 | | Bifacial | Yes | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year - **Cumulative output, 20 730:** 24,493 kWh - **Cumulative output, 20Q-745:** 25,191 kWh - **Gap:** 698 kWh ## Output when hot | Condition | Cell temperature | 20 730 | 20Q-745 | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 730 W | 745 W | 100.0% of rated power | | Cool, bright day | 40 °C | 698 W | 716 W | 95.7% of rated power | | Typical summer roof | 55 °C | 666 W | 687 W | 91.3% of rated power | | Hot roof | 70 °C | 635 W | 658 W | 87.0% of rated power | ## Against the whole database | Measure | 20 730 | 20Q-745 | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #708 | #301 | 13,953 | 20Q-745 leads by 407 places | | Power density | #790 | #335 | 13,953 | 20Q-745 leads by 455 places | | Heat behaviour | #2,146 | #511 | 13,953 | 20Q-745 leads by 1,635 places | | Weight | #5,958 | #4,778 | 13,953 | 20Q-745 leads by 1,180 places | | Warranty | #21 | #21 | 13,953 | Tied - the same position in the database | | Overall | #303 | #144 | 13,953 | 20Q-745 leads by 159 places | ## Questions ### Which panel is better: Trina Solar TSM-NEG21C.20 730 or Trina Solar TSM-NEG21C.20Q-745? According to our database: **Trina Solar TSM-NEG21C.20Q-745** has higher module efficiency (**24.00%** vs **23.50%**); **Trina Solar TSM-NEG21C.20Q-745** tolerates heat better (temp coeff **-0.260%/°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 Trina Solar TSM-NEG21C.20 730 and Trina Solar TSM-NEG21C.20Q-745? **Trina Solar TSM-NEG21C.20 730** has a module efficiency of **23.50%**, while **Trina Solar TSM-NEG21C.20Q-745** is **24.00%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Trina Solar TSM-NEG21C.20 730 use vs Trina Solar TSM-NEG21C.20Q-745? **Trina Solar TSM-NEG21C.20 730** uses **TOPCon** cells; **Trina Solar TSM-NEG21C.20Q-745** 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-NEG21C.20 730 and Trina Solar TSM-NEG21C.20Q-745? **Trina Solar TSM-NEG21C.20 730** has a **30 years** power warranty; **Trina Solar TSM-NEG21C.20Q-745** 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-NEG21C.20 730 and Trina Solar TSM-NEG21C.20Q-745 bifacial panels? Both **Trina Solar TSM-NEG21C.20 730** and **Trina Solar TSM-NEG21C.20Q-745** 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 - [Trina Solar TSM-NEG21C.20 730 vs Trina Solar TSM-NEG21C.20Q-760](https://comparepv.com/compare/trina-solar-tsm-neg21c-20-730/trina-solar-tsm-neg21c-20q-760) - 9 differences, the largest is module efficiency - [Trina Solar TSM-NEG21C.20 730 vs Trina Solar TSM-NEG21C.20Q-755](https://comparepv.com/compare/trina-solar-tsm-neg21c-20-730/trina-solar-tsm-neg21c-20q-755) - 7 differences, the largest is module efficiency - [Trina Solar TSM-NEG21C.20 730 vs Trina Solar TSM-NEG21C.20Q-750](https://comparepv.com/compare/trina-solar-tsm-neg21c-20-730/trina-solar-tsm-neg21c-20q-750) - 6 differences, the largest is module efficiency - [Trina Solar TSM-NEG21C.20 730 vs Trina Solar TSM-NEG21C.20-740](https://comparepv.com/compare/trina-solar-tsm-neg21c-20-730/trina-solar-co-ltd-tsm-neg21c-20-740) - 3 differences, the largest is module efficiency - [Trina Solar TSM-NEG21C.20 730 vs Trina Solar TSM-NEG21C.20 740](https://comparepv.com/compare/trina-solar-tsm-neg21c-20-730/trina-solar-tsm-neg21c-20-740) - 3 differences, the largest is module efficiency - [Trina Solar TSM-NEG21C.20 730 vs Trina Solar TSM-NEG21C.20Q-740](https://comparepv.com/compare/trina-solar-tsm-neg21c-20-730/trina-solar-tsm-neg21c-20q-740) - 6 differences, the largest is temperature coefficient --- Source: https://comparepv.com/compare/trina-solar-tsm-neg21c-20-730/trina-solar-tsm-neg21c-20q-745 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.