--- title: "Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD710XX - Solar Panel Comparison | ComparePV" description: "Compare Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD710XX side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/tongwei-solar-twmnf-66hd740/tw-solar-tongwei-twmnf-66hd710xx" updated: 2026-09-11 --- # Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD710XX 66HD740 leads on the differences that matter The largest is module efficiency: 0.90 pp more efficient. 12 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Tongwei TWMNF-66HD740](https://comparepv.com/panel/tongwei-solar-twmnf-66hd740) | [Tongwei TWMNF-66HD710XX](https://comparepv.com/panel/tw-solar-tongwei-twmnf-66hd710xx) | | Manufacturer | Tongwei | Tongwei | | Power | 740 Wp | 710 Wp | | Efficiency | 23.80 % | 22.90 % | | Technology | TOPCon | N-type | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 66HD740 | 66HD710XX | Difference | | --- | --- | --- | --- | | Module efficiency | 23.80 % | 22.90 % | +0.90 pp for 66HD740 | | Power density | 238.2 Wp/m² | 228.6 Wp/m² | +9.7 Wp/m² for 66HD740 | | Rated power | 740 Wp | 710 Wp | +30 W for 66HD740 | | Cell technology | TOPCon | N-type | TOPCon vs N-type | | Weight per kWp | 50.4 kg/kWp | 53.4 kg/kWp | -3.0 kg/kWp for 66HD740 | | Voltage at max power | 41.69 V | 40.69 V | 1.00 V apart | ## Every compared parameter | Parameter | 66HD740 | 66HD710XX | | --- | --- | --- | | Rated power | 740 Wp | 710 Wp | | Module efficiency | 23.80 % | 22.90 % | | Power density | 238.2 Wp/m² | 228.6 Wp/m² | | Open-circuit voltage | 49.80 V | 48.94 V | | Voltage at max power | 41.69 V | 40.69 V | | Short-circuit current | 18.81 A | 18.59 A | | Current at max power | 17.75 A | 17.64 A | | Temperature coefficient | -0.280 %/°C | -0.280 %/°C | | Dimensions | 2384x1303x33 mm | 2384x1303x33 mm | | Module area | 3.106 m² | 3.106 m² | | Weight | 37.3 kg | 37.9 kg | | Weight per kWp | 50.4 kg/kWp | 53.4 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | - | | Cell technology | TOPCon | N-type | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 132 | | Bifacial | Yes | Yes | ## Thirty-year yield Declared first-year losses, with 0.40% a year afterwards assumed for both panels, at 1,200 kWh/kWp a year Same temp coeff. for both panels (-0.280 %/°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, 66HD740:** 24,828 kWh - **Cumulative output, 66HD710XX:** 23,822 kWh - **Gap:** 1,006 kWh ## Output when hot | Condition | Cell temperature | 66HD740 | 66HD710XX | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 740 W | 710 W | 100.0% of rated power | | Cool, bright day | 40 °C | 709 W | 680 W | 95.8% of rated power | | Typical summer roof | 55 °C | 678 W | 650 W | 91.6% of rated power | | Hot roof | 70 °C | 647 W | 621 W | 87.4% of rated power | ## Against the whole database | Measure | 66HD740 | 66HD710XX | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #433 | #2,359 | 14,005 | 66HD740 leads by 1,926 places | | Power density | #431 | #2,474 | 14,005 | 66HD740 leads by 2,043 places | | Heat behaviour | #1,309 | #1,309 | 14,005 | Tied - the same position in the database | | Weight | #3,784 | #7,271 | 14,005 | 66HD740 leads by 3,487 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #183 | #817 | 14,005 | 66HD740 leads by 634 places | ## Questions ### Which panel is better: Tongwei TWMNF-66HD740 or Tongwei TWMNF-66HD710XX? According to our database: **Tongwei TWMNF-66HD740** has higher module efficiency (**23.80%** vs **22.90%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Tongwei TWMNF-66HD740 and Tongwei TWMNF-66HD710XX? **Tongwei TWMNF-66HD740** has a module efficiency of **23.80%**, while **Tongwei TWMNF-66HD710XX** is **22.90%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Tongwei TWMNF-66HD740 use vs Tongwei TWMNF-66HD710XX? **Tongwei TWMNF-66HD740** uses **TOPCon** cells; **Tongwei TWMNF-66HD710XX** uses **N-type**. 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 Tongwei TWMNF-66HD740 and Tongwei TWMNF-66HD710XX? **Tongwei TWMNF-66HD740** has a **30 years** power warranty; **Tongwei TWMNF-66HD710XX** 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 Tongwei TWMNF-66HD740 and Tongwei TWMNF-66HD710XX bifacial panels? Both **Tongwei TWMNF-66HD740** and **Tongwei TWMNF-66HD710XX** 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 - [Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD750](https://comparepv.com/compare/tongwei-solar-twmnf-66hd740/tongwei-solar-twmnf-66hd750) - 3 differences, the largest is module efficiency - [Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD745](https://comparepv.com/compare/tongwei-solar-twmnf-66hd740/tongwei-solar-twmnf-66hd745) - One difference: module efficiency - [Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD735](https://comparepv.com/compare/tongwei-solar-twmnf-66hd740/tongwei-solar-twmnf-66hd735) - The same specification on paper - [Tongwei TWMNF-66HD740 vs Tongwei TWMNF-66HD730](https://comparepv.com/compare/tongwei-solar-twmnf-66hd740/tongwei-solar-twmnf-66hd730) - 3 differences, the largest is module efficiency - [Tongwei TWMNF-66HD710XX vs Tongwei TWMNF-66HD720XX](https://comparepv.com/compare/tw-solar-tongwei-twmnf-66hd710xx/tw-solar-tongwei-twmnf-66hd720xx) - 3 differences, the largest is module efficiency - [Tongwei TWMNF-66HD710XX vs Tongwei TWMNF-66HD715XX](https://comparepv.com/compare/tw-solar-tongwei-twmnf-66hd710xx/tw-solar-tongwei-twmnf-66hd715xx) - The same specification on paper --- Source: https://comparepv.com/compare/tongwei-solar-twmnf-66hd740/tw-solar-tongwei-twmnf-66hd710xx 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.