--- title: "DAH Solar DHN-66Z20/DG(BW)-590W 590W Solar Panel - Specs & Review | ComparePV" description: "DAH Solar DHN-66Z20/DG(BW)-590W 590W solar panel. Specs: 21.84% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/dah-dhn-66z20-dg-bw-590w" updated: 2026-09-11 --- # DAH Solar DHN-66Z20/DG(BW)-590W Middle of its segment, modest efficiency 1,018 panels in the segment TOPCon 550-600 W ## Identity - **Manufacturer:** DAH Solar - **Model:** DHN-66Z20/DG(BW)-590W - **Series:** DHN-66Z20/DG(BW) 585–625W - **Rated power:** 590 W - **Cell technology:** TOPCon - **Bifacial:** yes ## How it compares Compared against segment TOPCon 550-600 W (1018 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 590 W | 580 W | Strong - top 18% | | | Module efficiency | 21.84% | 22.44% | Weak - bottom 15% | 6,985 | | Power density | 218.4 | 224.4 | Weak - bottom 15% | 6,954 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight (kg) | 32.5 kg | 31.2 kg | Typical | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 21.84% | 22.44% | Weak - bottom 15% | 6,985 | | Power density | 218.4 | 224.4 | Weak - bottom 15% | 6,954 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,165 | | Weight per kWp | 55.1 | 53.8 | Typical | 9,503 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Watch out for - **21.84% module efficiency** - Bottom 15% of the TOPCon 550-600 W segment, against a median of 22.44%. - **218.4 watts per square metre** - Bottom 15% of the TOPCon 550-600 W segment, against a median of 224.4. - **Best for:** Commercial and utility-scale. - **Not ideal for:** Tight roof space and roofs where every square metre has to count. ## Specification ### Electrical - **Rated power (Pmax):** 590 W - **Efficiency:** 21.84 % - **Voltage at Pmax (Vmp):** 39.70 V - **Current at Pmax (Imp):** 14.71 A - **Open-circuit voltage (Voc):** 47.20 V - **Short-circuit current (Isc):** 15.62 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.290 %/degC - **Temperature coefficient of Voc:** -0.250 %/degC - **Temperature coefficient of Isc:** 0.046 %/degC - **NOCT:** 45 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** TOPCon - **Cell count:** 132 - **Bifacial:** yes ### Physical - **Length:** 2382 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 32.5 kg - **Area:** 2.70 m2 - **Power density:** 218.4 Wp/m2 ### Warranty and degradation - **Product warranty:** 15 years - **Performance warranty:** 30 years - **Output guaranteed at end of warranty:** 87.4 % - **First-year degradation:** 1.00 % - **Output after 30 years:** 516 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 6985 of 14005 | | Power density | 6954 of 14005 | | Temperature coefficient | 2165 of 14005 | | Weight | 9503 of 14005 | | Warranty | 21 of 14005 | ## Pros - **N-type TOPCon – Reduced LID/LeTID Degradation** - N-type TOPCon cells eliminate the Light Induced Degradation characteristic of older P-type PERC technologies. In Polish climatic conditions—with frequent transitional seasons and low solar elevation angles—this translates into meaningfully higher annual energy yield compared to PERC modules of equivalent rated power. - **Up to 23.14% Efficiency – Top of the Segment** - The highest-tier variant in the series achieves 23.14% module efficiency, matching the Techwise Sun-Pursuit Plus TOPCon (23.14%) and outperforming the Longi Hi-MO 7 (23.1%) and Leapton LP182 (22.36%). Higher efficiency directly reduces module count and BoS costs per MW of installed capacity. - **Bifacial Double-Glass Construction** - The double-glass design eliminates the backsheet as a component susceptible to UV degradation and moisture ingress, improving laminate integrity and mechanical durability. Bifacial operation enables an additional 5–15% energy gain in ground-mount and flat-roof installations with high-reflectivity surfaces—at a ground albedo of 0.3, this represents several MWh per year for a typical PV plant. - **30-Year Linear Power Warranty** - The manufacturer provides a 30-year linear power output warranty, confirming stable degradation performance over the full operational lifetime of commercial and utility-scale PV installations. This is the premium TOPCon industry standard, on par with the Longi Hi-MO 7 and superior to the 25-year warranties offered by lower-tier manufacturers. - **BNEF Tier 1 – Bankability Confirmed Q4 2025** - DAH Solar maintains continuous Tier 1 status per BloombergNEF, including Q4 2025 under tightened criteria (project threshold raised to 10 MW). Tier 1 classification is a prerequisite for project finance and insurance on PV plants above 1 MW. ## Cons - **Product Warranty Limited to 15 Years** - The manufacturer offers only a 15-year product warranty covering materials and workmanship, whereas Longi Solar (Hi-MO 7) and most leading Tier-1 suppliers provide a standard 25-year product warranty. For projects with long financing horizons (15–20 years), this may be a limiting factor in negotiations with lenders or insurers. ## About this series The DAH DHN-66Z20/DG(BW) 585-625W series has been designed to maximize energy yield in spaces where every square meter counts, and to ensure stable performance for years to come. The use of **N-type TOPCon cells** results in lower degradation and improved energy production at higher temperatures and under less intense sunlight - which is particularly important in Polish conditions during transitional seasons. The modules utilize a **double-glass structure**, which enhances mechanical strength and improves the laminate's airtightness, reducing the risk of operational problems in demanding environments. An additional advantage is **bifaciality** - the panel can utilize reflected light from the ground, which helps to increase energy yield on flat roofs and in ground-mounted installations. The **multi-junction technology that minimizes microcracks** also deserves attention, as it allows the module to better withstand loads and thermal cycles. This makes it a sensible choice for PV farms, C&I installations, and large roofs, where durability, predictability, and lower BOS costs are key. ## Notable figures - Efficiency of 21.8% is 0.6pp below the \*\*TOPCon 550-600W\*\* median (22.4%) - 218.4 W/m² power density is 6.0 W/m² below \*\*TOPCon 550-600W\*\* median (224.4 W/m²) - requires larger installation area - At -0.29%/°C, hot weather performance is typical for \*\*TOPCon 550-600W\*\* panels - Weight of 32.5 kg is 1.3 kg above \*\*TOPCon 550-600W\*\* median (31.2 kg) - verify structural support - Bifacial design (80% factor) captures reflected light - adds 4-12% yield on ground-mount or white roof ## Questions ### What warranties cover the DAH Solar DHN-66Z20/DG(BW) 585–625W panels? The manufacturer provides a 15-year product warranty against material and workmanship defects, and a 30-year linear power output warranty. Thanks to N-type TOPCon cell technology, the annual degradation rate is lower than that of older P-type modules, meaning the module retains a significantly higher percentage of its nominal power after 30 years. This is one of the longest power output warranties available on the market in this product class. ### What is bifaciality and does it genuinely increase energy yield in the DHN-66Z20/DG(BW) series? Bifaciality means the panel generates electricity from both sides — the front face (direct irradiance) and the rear face (light reflected from the ground, snow, or a light-colored roofing membrane). In ground-mounted installations and flat-roof systems with a white substrate, the bifacial gain typically ranges from 5–15% compared to a monofacial module. On pitched roofs with dark roofing material, the bifacial effect is minimal. ### Does the DAH DHN-66Z20/DG(BW) series perform well under Polish weather conditions — overcast skies, frost, and low temperatures? Yes. N-type TOPCon cells feature a lower temperature coefficient of power and better response to diffuse irradiance than PERC cells. In Polish conditions — where overcast days are prevalent from October through March — this translates into measurably higher energy production during transitional seasons. The dual-glass construction also provides superior resistance to moisture ingress and frost. ### What is the efficiency of the DAH Solar DHN-66Z20/DG(BW) modules and how much space does a 10 kWp system require? Modules in this series achieve efficiency of up to approximately 22.9% (620–625W variant). As a result, a 10 kWp system using 620W panels requires only 16–17 modules and occupies approximately 27–29 m² of roof or ground area. This is a significant advantage in space-constrained installations or where land costs are high. ### What types of installations is the DAH DHN-66Z20/DG(BW) 585–625W series best suited for — residential, commercial, or utility-scale PV farms? Given its large form factor and power output of up to 625W, this series is optimal for utility-scale PV farms, industrial installations, and large commercial rooftops (C&I), where low BoS costs and high yield per module are critical. It can be deployed on a typical single-family residential roof only when the available space and structural load capacity permit — this should be verified with a structural engineer or system designer beforehand. ### How does the dual-glass (double glass) construction of the DHN-66Z20/DG(BW) series differ from a standard backsheet? In a double glass module, the conventional polymer backsheet is replaced by tempered glass, eliminating the risk of laminate cracking, moisture ingress, and backsheet yellowing over decades of operation. This results in higher resistance to snow and wind loads, improved long-term weatherproofing, and extended module service life. For this reason, the double glass variant is particularly recommended for environmentally demanding locations and for installations with a long investment horizon. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/en-dhn-66z20-dg-bw-585-625w-4e08aff12326.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [Longi Solar LR7-60HVH-560M](https://comparepv.com/panel/longi-lr7-60hvh-560m) | 560 W | -30 W, lighter, +3.0 pp | | [AIKO AIKO-A640-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a640-mae72mw) | 640 W | +50 W, lighter, +3.0 pp | | [Longi Solar LR7-60HVH-555M](https://comparepv.com/panel/longi-lr7-60hvh-555m) | 555 W | -35 W, lighter, +2.8 pp | | [AIKO AIKO-A635-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a635-mae72mw) | 635 W | +45 W, lighter, +2.8 pp | | [AIKO AIKO-A630-MAH72Dw](https://comparepv.com/panel/aiko-aiko-a630-mah72dw) | 630 W | +40 W, cooler, +2.6 pp | | [Longi Solar LR7-60HVHL-550M](https://comparepv.com/panel/longi-lr7-60hvhl-550m) | 550 W | -40 W, 16 kg lighter, +2.6 pp | | [DAH Solar DHN-66Z20/DG(BW)-585W](https://comparepv.com/panel/dah-dhn-66z20-dg-bw-585w) | 585 W | Very close match | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +90 W, lighter, +3.4 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +85 W, lighter, +3.2 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +110 W, cooler, +3.2 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +105 W, cooler, +3.1 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | +80 W, lighter, +3.0 pp | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | +80 W, lighter, +3.0 pp | | [Jinko Solar JKM650-670N-66QL6-BDV (670W class)](https://comparepv.com/panel/jinko-solar-jkm650-670n-66ql6-bdv-670w-class) | 670 W | +80 W, cooler, +3.0 pp | --- Source: https://comparepv.com/panel/dah-dhn-66z20-dg-bw-590w Not in this file, on the page: the I-V and temperature curves lifted from the manufacturer's datasheet, a thirty-year output simulator, a bifacial gain calculator and alternatives filtered by how closely they match these dimensions.