--- title: "Tongwei TWMNH-54HD vs Tongwei TWMNH-66HS - Solar Panel Comparison | ComparePV" description: "Compare Tongwei TWMNH-54HD vs Tongwei TWMNH-66HS side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/tongwei-twmnh-54hd/tongwei-twmnh-66hs" updated: 2026-09-11 --- # Tongwei TWMNH-54HD vs Tongwei TWMNH-66HS 66HS leads on the differences that matter The largest is module efficiency: 4.07 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 TWMNH-54HD](https://comparepv.com/panel/tongwei-twmnh-54hd) | [Tongwei TWMNH-66HS](https://comparepv.com/panel/tongwei-twmnh-66hs) | | Manufacturer | Tongwei | Tongwei | | Power | 515 Wp | 625 Wp | | Efficiency | 19.07 % | 23.14 % | | Technology | TOPCon | TOPCon | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 54HD | 66HS | Difference | | --- | --- | --- | --- | | Module efficiency | 19.07 % | 23.14 % | +4.07 pp for 66HS | | Rated power | 515 Wp | 625 Wp | +110 W for 66HS | | Power density | 190.7 Wp/m² | 231.4 Wp/m² | +40.7 Wp/m² for 66HS | | Weight per kWp | 56.3 kg/kWp | 46.4 kg/kWp | -9.9 kg/kWp for 66HS | | Open-circuit voltage | 40.60 V | 49.25 V | 8.65 V apart | | Voltage at max power | 34.43 V | 40.77 V | 6.34 V apart | ## Every compared parameter | Parameter | 54HD | 66HS | | --- | --- | --- | | Rated power | 515 Wp | 625 Wp | | Module efficiency | 19.07 % | 23.14 % | | Power density | 190.7 Wp/m² | 231.4 Wp/m² | | Open-circuit voltage | 40.60 V | 49.25 V | | Voltage at max power | 34.43 V | 40.77 V | | Short-circuit current | 15.98 A | 16.14 A | | Current at max power | 14.96 A | 15.33 A | | Temperature coefficient | -0.280 %/°C | -0.280 %/°C | | Dimensions | 2382x1134x30 mm | 2382x1134x30 mm | | Module area | 2.701 m² | 2.701 m² | | Weight | 29.0 kg | 29.0 kg | | Weight per kWp | 56.3 kg/kWp | 46.4 kg/kWp | | Product warranty | 15 yrs | 15 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | - | - | | Cell technology | TOPCon | TOPCon | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 132 | | Bifacial | Yes | Yes | ## Thirty-year yield A 1.0% first-year loss then 0.40% a year, 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, 54HD:** 17,279 kWh - **Cumulative output, 66HS:** 20,970 kWh - **Gap:** 3,691 kWh ## Output when hot | Condition | Cell temperature | 54HD | 66HS | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 515 W | 625 W | 100.0% of rated power | | Cool, bright day | 40 °C | 493 W | 599 W | 95.8% of rated power | | Typical summer roof | 55 °C | 472 W | 573 W | 91.6% of rated power | | Hot roof | 70 °C | 450 W | 546 W | 87.4% of rated power | ## Against the whole database | Measure | 54HD | 66HS | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #12,923 | #1,509 | 14,005 | 66HS leads by 11,414 places | | Power density | #12,908 | #1,513 | 14,005 | 66HS leads by 11,395 places | | Heat behaviour | #1,309 | #1,309 | 14,005 | Tied - the same position in the database | | Weight | #10,565 | #1,141 | 14,005 | 66HS leads by 9,424 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #9,980 | #1,789 | 14,005 | 66HS leads by 8,191 places | ## Questions ### Which panel is better: Tongwei TWMNH-54HD or Tongwei TWMNH-66HS? According to our database: **Tongwei TWMNH-66HS** has higher module efficiency (**23.14%** vs **19.07%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Tongwei TWMNH-54HD and Tongwei TWMNH-66HS? **Tongwei TWMNH-54HD** has a module efficiency of **19.07%**, while **Tongwei TWMNH-66HS** is **23.14%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Tongwei TWMNH-54HD use vs Tongwei TWMNH-66HS? **Tongwei TWMNH-54HD** uses **TOPCon** cells; **Tongwei TWMNH-66HS** 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 Tongwei TWMNH-54HD and Tongwei TWMNH-66HS? **Tongwei TWMNH-54HD** has a **30 years** power warranty; **Tongwei TWMNH-66HS** 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 TWMNH-54HD and Tongwei TWMNH-66HS bifacial panels? Both **Tongwei TWMNH-54HD** and **Tongwei TWMNH-66HS** 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 TWMNH-54HD vs Tongwei THC G12-66 Bifacial](https://comparepv.com/compare/tongwei-twmnh-54hd/tongwei-thc-g12-66-bifacial) - 11 differences, the largest is module efficiency - [Tongwei TWMNH-54HD vs Tongwei TWMNF-66HD](https://comparepv.com/compare/tongwei-twmnh-54hd/tongwei-twmnf-66hd) - 11 differences, the largest is module efficiency - [Tongwei TWMNH-54HD vs Tongwei TWMNH-66HD](https://comparepv.com/compare/tongwei-twmnh-54hd/tongwei-twmnh-66hd) - 6 differences, the largest is module efficiency - [Tongwei TWMNH-54HD vs Tongwei TWMNH-48HC](https://comparepv.com/compare/tongwei-twmnh-54hd/tongwei-twmnh-48hc) - 6 differences, the largest is module efficiency - [Tongwei TWMNH-54HD vs Tongwei TWMNF-66HD750](https://comparepv.com/compare/tongwei-twmnh-54hd/tongwei-solar-twmnf-66hd750) - 12 differences, the largest is module efficiency - [Tongwei TWMNH-54HD vs Tongwei TWMNF-66HD745](https://comparepv.com/compare/tongwei-twmnh-54hd/tongwei-solar-twmnf-66hd745) - 12 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/tongwei-twmnh-54hd/tongwei-twmnh-66hs 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.