--- title: "Tongwei TWMHF-66HD720X vs Tongwei TWMHF-66HD730X - Solar Panel Comparison | ComparePV" description: "Compare Tongwei TWMHF-66HD720X vs Tongwei TWMHF-66HD730X side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/tw-solar-twmhf-66hd720x/tw-solar-twmhf-66hd730x" updated: 2026-09-11 --- # Tongwei TWMHF-66HD720X vs Tongwei TWMHF-66HD730X 66HD730X leads on the differences that matter The largest is module efficiency: 0.30 pp more efficient. 16 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Tongwei TWMHF-66HD720X](https://comparepv.com/panel/tw-solar-twmhf-66hd720x) | [Tongwei TWMHF-66HD730X](https://comparepv.com/panel/tw-solar-twmhf-66hd730x) | | Manufacturer | Tongwei | Tongwei | | Power | 720 Wp | 730 Wp | | Efficiency | 23.20 % | 23.50 % | | Technology | N-type | N-type | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 66HD720X | 66HD730X | Difference | | --- | --- | --- | --- | | Module efficiency | 23.20 % | 23.50 % | +0.30 pp for 66HD730X | | Power density | 231.8 Wp/m² | 235.0 Wp/m² | +3.2 Wp/m² for 66HD730X | | Rated power | 720 Wp | 730 Wp | +10 W for 66HD730X | ## Every compared parameter | Parameter | 66HD720X | 66HD730X | | --- | --- | --- | | Rated power | 720 Wp | 730 Wp | | Module efficiency | 23.20 % | 23.50 % | | Power density | 231.8 Wp/m² | 235.0 Wp/m² | | Open-circuit voltage | 50.30 V | 50.46 V | | Voltage at max power | 41.94 V | 42.13 V | | Short-circuit current | 18.08 A | 18.28 A | | Current at max power | 17.17 A | 17.33 A | | Temperature coefficient | -0.240 %/°C | -0.240 %/°C | | Dimensions | 2384x1303x33 mm | 2384x1303x33 mm | | Module area | 3.106 m² | 3.106 m² | | Weight | 37.0 kg | 37.0 kg | | Weight per kWp | 51.4 kg/kWp | 50.7 kg/kWp | | Product warranty | 15 yrs | 15 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.38 %/yr | 0.38 %/yr | | Cell technology | N-type | N-type | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 132 | | Bifacial | Yes | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year Same temp coeff. for both panels (-0.240 %/°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, 66HD720X:** 24,251 kWh - **Cumulative output, 66HD730X:** 24,588 kWh - **Gap:** 337 kWh ## Output when hot | Condition | Cell temperature | 66HD720X | 66HD730X | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 720 W | 730 W | 100.0% of rated power | | Cool, bright day | 40 °C | 694 W | 704 W | 96.4% of rated power | | Typical summer roof | 55 °C | 668 W | 677 W | 92.8% of rated power | | Hot roof | 70 °C | 642 W | 651 W | 89.2% of rated power | ## Against the whole database | Measure | 66HD720X | 66HD730X | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #1,306 | #716 | 14,005 | 66HD730X leads by 590 places | | Power density | #1,347 | #800 | 14,005 | 66HD730X leads by 547 places | | Heat behaviour | #13 | #13 | 14,005 | Tied - the same position in the database | | Weight | #4,775 | #4,111 | 14,005 | 66HD730X leads by 664 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #330 | #196 | 14,005 | 66HD730X leads by 134 places | ## Questions ### Which panel is better: Tongwei TWMHF-66HD720X or Tongwei TWMHF-66HD730X? According to our database: **Tongwei TWMHF-66HD730X** has higher module efficiency (**23.50%** vs **23.20%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Tongwei TWMHF-66HD720X and Tongwei TWMHF-66HD730X? **Tongwei TWMHF-66HD720X** has a module efficiency of **23.20%**, while **Tongwei TWMHF-66HD730X** is **23.50%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Tongwei TWMHF-66HD720X use vs Tongwei TWMHF-66HD730X? **Tongwei TWMHF-66HD720X** uses **N-type** cells; **Tongwei TWMHF-66HD730X** 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 TWMHF-66HD720X and Tongwei TWMHF-66HD730X? **Tongwei TWMHF-66HD720X** has a **30 years** power warranty; **Tongwei TWMHF-66HD730X** 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 TWMHF-66HD720X and Tongwei TWMHF-66HD730X bifacial panels? Both **Tongwei TWMHF-66HD720X** and **Tongwei TWMHF-66HD730X** 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 TWMHF-66HD720X vs Tongwei TWMHF-66HD740X](https://comparepv.com/compare/tw-solar-twmhf-66hd720x/tw-solar-twmhf-66hd740x) - 3 differences, the largest is module efficiency - [Tongwei TWMHF-66HD720X vs Tongwei TWMHF-66HD735X](https://comparepv.com/compare/tw-solar-twmhf-66hd720x/tw-solar-twmhf-66hd735x) - 3 differences, the largest is module efficiency - [Tongwei TWMHF-66HD720X vs Tongwei TWMHF-66HD725X](https://comparepv.com/compare/tw-solar-twmhf-66hd720x/tw-solar-twmhf-66hd725x) - The same specification on paper - [Tongwei TWMHF-66HD720X vs Tongwei TWMHF-66HD715X](https://comparepv.com/compare/tw-solar-twmhf-66hd720x/tw-solar-twmhf-66hd715x) - One difference: module efficiency - [Tongwei TWMHF-66HD720X vs Tongwei TWMNF-66HD750](https://comparepv.com/compare/tw-solar-twmhf-66hd720x/tongwei-solar-twmnf-66hd750) - 8 differences, the largest is module efficiency - [Tongwei TWMHF-66HD720X vs Tongwei TWMNF-66HD745](https://comparepv.com/compare/tw-solar-twmhf-66hd720x/tongwei-solar-twmnf-66hd745) - 8 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/tw-solar-twmhf-66hd720x/tw-solar-twmhf-66hd730x 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.