--- title: "Tongwei TWMNH-66HD630 vs Tongwei TWMNH-66HD645 - Solar Panel Comparison | ComparePV" description: "Compare Tongwei TWMNH-66HD630 vs Tongwei TWMNH-66HD645 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-twmnh-66hd630/tongwei-solar-twmnh-66hd645" updated: 2026-09-11 --- # Tongwei TWMNH-66HD630 vs Tongwei TWMNH-66HD645 66HD645 leads on the differences that matter The largest is module efficiency: 0.60 pp more efficient. 15 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Tongwei TWMNH-66HD630](https://comparepv.com/panel/tongwei-solar-twmnh-66hd630) | [Tongwei TWMNH-66HD645](https://comparepv.com/panel/tongwei-solar-twmnh-66hd645) | | Manufacturer | Tongwei | Tongwei | | Power | 630 Wp | 645 Wp | | Efficiency | 23.30 % | 23.90 % | | Technology | TOPCon | N-type | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 66HD630 | 66HD645 | Difference | | --- | --- | --- | --- | | Module efficiency | 23.30 % | 23.90 % | +0.60 pp for 66HD645 | | Power density | 233.2 Wp/m² | 238.8 Wp/m² | +5.6 Wp/m² for 66HD645 | | Rated power | 630 Wp | 645 Wp | +15 W for 66HD645 | | Cell technology | TOPCon | N-type | TOPCon vs N-type | ## Every compared parameter | Parameter | 66HD630 | 66HD645 | | --- | --- | --- | | Rated power | 630 Wp | 645 Wp | | Module efficiency | 23.30 % | 23.90 % | | Power density | 233.2 Wp/m² | 238.8 Wp/m² | | Open-circuit voltage | 49.50 V | 49.85 V | | Voltage at max power | 41.10 V | 41.51 V | | Short-circuit current | 16.18 A | 16.39 A | | Current at max power | 15.33 A | 15.54 A | | Temperature coefficient | -0.280 %/°C | -0.280 %/°C | | Dimensions | 2382x1134x30 mm | 2382x1134x30 mm | | Module area | 2.701 m² | 2.701 m² | | Weight | 32.5 kg | 32.2 kg | | Weight per kWp | 51.6 kg/kWp | 49.9 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.40 %/yr | | Cell technology | TOPCon | 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 (-0.280 %/°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, 66HD630:** 21,138 kWh - **Cumulative output, 66HD645:** 21,641 kWh - **Gap:** 503 kWh ## Output when hot | Condition | Cell temperature | 66HD630 | 66HD645 | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 630 W | 645 W | 100.0% of rated power | | Cool, bright day | 40 °C | 604 W | 618 W | 95.8% of rated power | | Typical summer roof | 55 °C | 577 W | 591 W | 91.6% of rated power | | Hot roof | 70 °C | 551 W | 564 W | 87.4% of rated power | ## Against the whole database | Measure | 66HD630 | 66HD645 | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #1,017 | #351 | 14,005 | 66HD645 leads by 666 places | | Power density | #1,003 | #356 | 14,005 | 66HD645 leads by 647 places | | Heat behaviour | #1,309 | #1,309 | 14,005 | Tied - the same position in the database | | Weight | #4,960 | #3,293 | 14,005 | 66HD645 leads by 1,667 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #1,962 | #1,342 | 14,005 | 66HD645 leads by 620 places | ## Questions ### Which panel is better: Tongwei TWMNH-66HD630 or Tongwei TWMNH-66HD645? According to our database: **Tongwei TWMNH-66HD645** has higher module efficiency (**23.90%** vs **23.30%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Tongwei TWMNH-66HD630 and Tongwei TWMNH-66HD645? **Tongwei TWMNH-66HD630** has a module efficiency of **23.30%**, while **Tongwei TWMNH-66HD645** is **23.90%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Tongwei TWMNH-66HD630 use vs Tongwei TWMNH-66HD645? **Tongwei TWMNH-66HD630** uses **TOPCon** cells; **Tongwei TWMNH-66HD645** 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 TWMNH-66HD630 and Tongwei TWMNH-66HD645? **Tongwei TWMNH-66HD630** has a **30 years** power warranty; **Tongwei TWMNH-66HD645** 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-66HD630 and Tongwei TWMNH-66HD645 bifacial panels? Both **Tongwei TWMNH-66HD630** and **Tongwei TWMNH-66HD645** 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-66HD630 vs Tongwei TWMNF-66HD750](https://comparepv.com/compare/tongwei-solar-twmnh-66hd630/tongwei-solar-twmnf-66hd750) - 8 differences, the largest is module efficiency - [Tongwei TWMNH-66HD630 vs Tongwei TWMNF-66HD745](https://comparepv.com/compare/tongwei-solar-twmnh-66hd630/tongwei-solar-twmnf-66hd745) - 8 differences, the largest is module efficiency - [Tongwei TWMNH-66HD630 vs Tongwei TWMNF-66HD740](https://comparepv.com/compare/tongwei-solar-twmnh-66hd630/tongwei-solar-twmnf-66hd740) - 8 differences, the largest is rated power - [Tongwei TWMNH-66HD630 vs Tongwei TWMHF-66HD740X](https://comparepv.com/compare/tongwei-solar-twmnh-66hd630/tw-solar-twmhf-66hd740x) - 13 differences, the largest is temperature coefficient - [Tongwei TWMNH-66HD630 vs Tongwei TWMNF-66HD735](https://comparepv.com/compare/tongwei-solar-twmnh-66hd630/tongwei-solar-twmnf-66hd735) - 8 differences, the largest is rated power - [Tongwei TWMNH-66HD630 vs Tongwei TWMHF-66HD735X](https://comparepv.com/compare/tongwei-solar-twmnh-66hd630/tw-solar-twmhf-66hd735x) - 13 differences, the largest is temperature coefficient --- Source: https://comparepv.com/compare/tongwei-solar-twmnh-66hd630/tongwei-solar-twmnh-66hd645 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.