--- title: "DAH Solar DHN-66Z20/DG(BW)-625W vs Longi Solar LR8-66HVD-645M - Solar Panel Comparison | ComparePV" description: "Compare DAH Solar DHN-66Z20/DG(BW)-625W vs Longi Solar LR8-66HVD-645M side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/dah-dhn-66z20-dg-bw-625w/longi-lr8-66hvd-645m" image: "https://comparepv.com/og/compare/panels/dah-dhn-66z20-dg-bw-625w/longi-lr8-66hvd-645m.png" updated: 2026-09-11 --- # DAH Solar DHN-66Z20/DG(BW)-625W vs Longi Solar LR8-66HVD-645M LR8-66HVD-645M leads on the differences that matter The largest is module efficiency: 0.74 pp more efficient. 9 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 | [DAH Solar DHN-66Z20/DG(BW)-625W](https://comparepv.com/panel/dah-dhn-66z20-dg-bw-625w) | [Longi Solar LR8-66HVD-645M](https://comparepv.com/panel/longi-lr8-66hvd-645m) | | Manufacturer | DAH Solar | Longi Solar | | Power | 625 Wp | 645 Wp | | Efficiency | 23.14 % | 23.88 % | | Technology | TOPCon | Back Contact | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | DHN-66Z20/DG(BW)-625W | LR8-66HVD-645M | Difference | | --- | --- | --- | --- | | Module efficiency | 23.14 % | 23.88 % | +0.74 pp for LR8-66HVD-645M | | Temperature coefficient | -0.290 %/°C | -0.260 %/°C | +0.030 %/°C for LR8-66HVD-645M | | Power density | 231.4 Wp/m² | 238.8 Wp/m² | +7.4 Wp/m² for LR8-66HVD-645M | | Rated power | 625 Wp | 645 Wp | +20 W for LR8-66HVD-645M | | Cell technology | TOPCon | Back Contact | TOPCon vs Back Contact | | Weight | 32.5 kg | 33.5 kg | -1.0 kg for DHN-66Z20/DG(BW)-625W | | Open-circuit voltage | 48.40 V | 49.62 V | 1.22 V apart | | Short-circuit current | 15.96 A | 16.46 A | 0.50 A apart | | Current at max power | 14.96 A | 15.78 A | 0.82 A apart | ## Every compared parameter | Parameter | DHN-66Z20/DG(BW)-625W | LR8-66HVD-645M | | --- | --- | --- | | Rated power | 625 Wp | 645 Wp | | Module efficiency | 23.14 % | 23.88 % | | Power density | 231.4 Wp/m² | 238.8 Wp/m² | | Open-circuit voltage | 48.40 V | 49.62 V | | Voltage at max power | 41.10 V | 40.88 V | | Short-circuit current | 15.96 A | 16.46 A | | Current at max power | 14.96 A | 15.78 A | | Temperature coefficient | -0.290 %/°C | -0.260 %/°C | | Dimensions | 2382x1134x30 mm | 2382x1134x30 mm | | Module area | 2.701 m² | 2.701 m² | | Weight | 32.5 kg | 33.5 kg | | Weight per kWp | 52.0 kg/kWp | 51.9 kg/kWp | | Product warranty | 15 yrs | 15 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | - | 0.35 %/yr | | Cell technology | TOPCon | Back Contact | | 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 - **Cumulative output, DHN-66Z20/DG(BW)-625W:** 20,970 kWh - **Cumulative output, LR8-66HVD-645M:** 21,641 kWh - **Gap:** 671 kWh ## Output when hot | Condition | Cell temperature | DHN-66Z20/DG(BW)-625W | LR8-66HVD-645M | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 625 W | 645 W | 100.0% of rated power | | Cool, bright day | 40 °C | 598 W | 620 W | 95.7% of rated power | | Typical summer roof | 55 °C | 571 W | 595 W | 91.3% of rated power | | Hot roof | 70 °C | 543 W | 570 W | 87.0% of rated power | ## Against the whole database | Measure | DHN-66Z20/DG(BW)-625W | LR8-66HVD-645M | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #1,509 | #394 | 14,005 | LR8-66HVD-645M leads by 1,115 places | | Power density | #1,513 | #356 | 14,005 | LR8-66HVD-645M leads by 1,157 places | | Heat behaviour | #2,165 | #511 | 14,005 | LR8-66HVD-645M leads by 1,654 places | | Weight | #5,417 | #5,361 | 14,005 | LR8-66HVD-645M leads by 56 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #1,833 | #1,084 | 14,005 | LR8-66HVD-645M leads by 749 places | ## Questions ### Which panel is better: DAH Solar DHN-66Z20/DG(BW)-625W or Longi Solar LR8-66HVD-645M? According to our database: **Longi Solar LR8-66HVD-645M** has higher module efficiency (**23.88%** vs **23.14%**); **Longi Solar LR8-66HVD-645M** 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 DAH Solar DHN-66Z20/DG(BW)-625W and Longi Solar LR8-66HVD-645M? **DAH Solar DHN-66Z20/DG(BW)-**625 W**** has a module efficiency of **23.14%**, while **Longi Solar LR8-66HVD-645M** is **23.88%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does DAH Solar DHN-66Z20/DG(BW)-625W use vs Longi Solar LR8-66HVD-645M? **DAH Solar DHN-66Z20/DG(BW)-**625 W**** uses **TOPCon** cells; **Longi Solar LR8-66HVD-645M** uses **Back Contact**. 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 DAH Solar DHN-66Z20/DG(BW)-625W and Longi Solar LR8-66HVD-645M? **DAH Solar DHN-66Z20/DG(BW)-**625 W**** has a **30 years** power warranty; **Longi Solar LR8-66HVD-645M** 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 DAH Solar DHN-66Z20/DG(BW)-625W and Longi Solar LR8-66HVD-645M bifacial panels? Both **DAH Solar DHN-66Z20/DG(BW)-**625 W**** and **Longi Solar LR8-66HVD-645M** 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 - [DAH Solar DHN-66Z20/DG(BW)-625W vs DAH Solar DHN-66Z20/DG(BW)-620W](https://comparepv.com/compare/dah-dhn-66z20-dg-bw-625w/dah-dhn-66z20-dg-bw-620w) - The same specification on paper - [DAH Solar DHN-66Z20/DG(BW)-625W vs DAH Solar DHN-66Z20/DG(BW)-615W](https://comparepv.com/compare/dah-dhn-66z20-dg-bw-625w/dah-dhn-66z20-dg-bw-615w) - 3 differences, the largest is module efficiency - [DAH Solar DHN-66Z20/DG(BW)-625W vs DAH Solar DHN-66Z20/DG(BW)-610W](https://comparepv.com/compare/dah-dhn-66z20-dg-bw-625w/dah-dhn-66z20-dg-bw-610w) - 3 differences, the largest is module efficiency - [DAH Solar DHN-66Z20/DG(BW)-625W vs DAH Solar DHN-66Z20/DG(BW)-605W](https://comparepv.com/compare/dah-dhn-66z20-dg-bw-625w/dah-dhn-66z20-dg-bw-605w) - 3 differences, the largest is module efficiency - [DAH Solar DHN-66Z20/DG(BW)-625W vs DAH Solar DHN-66Z20/DG(BW)-600W](https://comparepv.com/compare/dah-dhn-66z20-dg-bw-625w/dah-dhn-66z20-dg-bw-600w) - 5 differences, the largest is module efficiency - [DAH Solar DHN-66Z20/DG(BW)-625W vs DAH Solar DHN-66Z20/DG(BW)-595W](https://comparepv.com/compare/dah-dhn-66z20-dg-bw-625w/dah-dhn-66z20-dg-bw-595w) - 6 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/dah-dhn-66z20-dg-bw-625w/longi-lr8-66hvd-645m 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.