--- title: "DMEGC DM645M10T-B78HSW vs DMEGC DM590M10T-B72HSW - Solar Panel Comparison | ComparePV" description: "Compare DMEGC DM645M10T-B78HSW vs DMEGC DM590M10T-B72HSW side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/dmegc-hengdian-group-dm645m10t-b78hsw/dmegc-hengdian-group-dmegc-magnetics-co-ltd-dm590m10t-b72hsw" updated: 2026-09-11 --- # DMEGC DM645M10T-B78HSW vs DMEGC DM590M10T-B72HSW DM645M10T-B78HSW leads on the differences that matter The largest is rated power: 55 W more power. 11 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [DMEGC DM645M10T-B78HSW](https://comparepv.com/panel/dmegc-hengdian-group-dm645m10t-b78hsw) | [DMEGC DM590M10T-B72HSW](https://comparepv.com/panel/dmegc-hengdian-group-dmegc-magnetics-co-ltd-dm590m10t-b72hsw) | | Manufacturer | DMEGC | DMEGC | | Power | 645 Wp | 590 Wp | | Efficiency | 23.10 % | 22.80 % | | Technology | TOPCon | TOPCon | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | DM645M10T-B78HSW | DM590M10T-B72HSW | Difference | | --- | --- | --- | --- | | Rated power | 645 Wp | 590 Wp | +55 W for DM645M10T-B78HSW | | Open-circuit voltage | 57.90 V | 52.90 V | 5.00 V apart | | Module area | 2.795 m² | 2.583 m² | 0.212 m² apart | | Module efficiency | 23.10 % | 22.80 % | +0.30 pp for DM645M10T-B78HSW | | Weight | 33.5 kg | 31.8 kg | -1.7 kg for DM590M10T-B72HSW | | Cell count | 156 | 144 | 12 cells apart | | Voltage at max power | 48.05 V | 44.23 V | 3.82 V apart | | Dimensions | 2465x1134x30 mm | 2278x1134x30 mm | 2465x1134x30 mm vs 2278x1134x30 mm | ## Every compared parameter | Parameter | DM645M10T-B78HSW | DM590M10T-B72HSW | | --- | --- | --- | | Rated power | 645 Wp | 590 Wp | | Module efficiency | 23.10 % | 22.80 % | | Power density | 230.7 Wp/m² | 228.4 Wp/m² | | Open-circuit voltage | 57.90 V | 52.90 V | | Voltage at max power | 48.05 V | 44.23 V | | Short-circuit current | 14.19 A | 14.11 A | | Current at max power | 13.44 A | 13.36 A | | Temperature coefficient | -0.290 %/°C | -0.290 %/°C | | Dimensions | 2465x1134x30 mm | 2278x1134x30 mm | | Module area | 2.795 m² | 2.583 m² | | Weight | 33.5 kg | 31.8 kg | | Weight per kWp | 51.9 kg/kWp | 53.9 kg/kWp | | Product warranty | 15 yrs | 15 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.40 %/yr | | Cell technology | TOPCon | TOPCon | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 156 | 144 | | 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 (-0.290 %/°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, DM645M10T-B78HSW:** 21,641 kWh - **Cumulative output, DM590M10T-B72HSW:** 19,796 kWh - **Gap:** 1,845 kWh ## Output when hot | Condition | Cell temperature | DM645M10T-B78HSW | DM590M10T-B72HSW | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 645 W | 590 W | 100.0% of rated power | | Cool, bright day | 40 °C | 617 W | 564 W | 95.7% of rated power | | Typical summer roof | 55 °C | 589 W | 539 W | 91.3% of rated power | | Hot roof | 70 °C | 561 W | 513 W | 87.0% of rated power | ## Against the whole database | Measure | DM645M10T-B78HSW | DM590M10T-B72HSW | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #1,570 | #2,714 | 14,005 | DM645M10T-B78HSW leads by 1,144 places | | Power density | #1,654 | #2,598 | 14,005 | DM645M10T-B78HSW leads by 944 places | | Heat behaviour | #2,165 | #2,165 | 14,005 | Tied - the same position in the database | | Weight | #5,361 | #8,021 | 14,005 | DM645M10T-B78HSW leads by 2,660 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #1,491 | #3,167 | 14,005 | DM645M10T-B78HSW leads by 1,676 places | ## Questions ### Which panel is better: DMEGC DM645M10T-B78HSW or DMEGC DM590M10T-B72HSW? According to our database: **DMEGC DM645M10T-B78HSW** has higher module efficiency (**23.10%** vs **22.80%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of DMEGC DM645M10T-B78HSW and DMEGC DM590M10T-B72HSW? **DMEGC DM645M10T-B78HSW** has a module efficiency of **23.10%**, while **DMEGC DM590M10T-B72HSW** is **22.80%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does DMEGC DM645M10T-B78HSW use vs DMEGC DM590M10T-B72HSW? **DMEGC DM645M10T-B78HSW** uses **TOPCon** cells; **DMEGC DM590M10T-B72HSW** 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 DMEGC DM645M10T-B78HSW and DMEGC DM590M10T-B72HSW? **DMEGC DM645M10T-B78HSW** has a **30 years** power warranty; **DMEGC DM590M10T-B72HSW** 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 DMEGC DM645M10T-B78HSW and DMEGC DM590M10T-B72HSW bifacial panels? Both **DMEGC DM645M10T-B78HSW** and **DMEGC DM590M10T-B72HSW** 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 - [DMEGC DM645M10T-B78HSW vs DMEGC DM650M10T-B78HSW](https://comparepv.com/compare/dmegc-hengdian-group-dm645m10t-b78hsw/dmegc-hengdian-group-dm650m10t-b78hsw) - One difference: module efficiency - [DMEGC DM645M10T-B78HSW vs DMEGC DM640M10T-B78HSW](https://comparepv.com/compare/dmegc-hengdian-group-dm645m10t-b78hsw/dmegc-hengdian-group-dm640m10t-b78hsw) - One difference: module efficiency - [DMEGC DM645M10T-B78HSW vs DMEGC DM635M10T-B78HSW](https://comparepv.com/compare/dmegc-hengdian-group-dm645m10t-b78hsw/dmegc-hengdian-group-dm635m10t-b78hsw) - 3 differences, the largest is module efficiency - [DMEGC DM645M10T-B78HSW vs DMEGC DM630M10T-B78HSW](https://comparepv.com/compare/dmegc-hengdian-group-dm645m10t-b78hsw/dmegc-hengdian-group-dm630m10t-b78hsw) - 3 differences, the largest is module efficiency - [DMEGC DM645M10T-B78HSW vs DMEGC DM600M10T-B72HSW](https://comparepv.com/compare/dmegc-hengdian-group-dm645m10t-b78hsw/dmegc-hengdian-group-dmegc-magnetics-co-ltd-dm600m10t-b72hsw) - 7 differences, the largest is rated power - [DMEGC DM645M10T-B78HSW vs DMEGC DM595M10T-B72HSW](https://comparepv.com/compare/dmegc-hengdian-group-dm645m10t-b78hsw/dmegc-hengdian-group-dmegc-magnetics-co-ltd-dm595m10t-b72hsw) - 7 differences, the largest is rated power --- Source: https://comparepv.com/compare/dmegc-hengdian-group-dm645m10t-b78hsw/dmegc-hengdian-group-dmegc-magnetics-co-ltd-dm590m10t-b72hsw 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.