--- title: "GCL GCL-NT12/66GDF-725 vs GCL GCL-NT12/66GDF 725 - Solar Panel Comparison | ComparePV" description: "Compare GCL GCL-NT12/66GDF-725 vs GCL GCL-NT12/66GDF 725 side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/gcl-gcl-nt12-66gdf-725/gcl-gcl-nt12-66gdf-725-1" updated: 2026-09-11 --- # GCL GCL-NT12/66GDF-725 vs GCL GCL-NT12/66GDF 725 Identical on every published parameter All 18 comparable parameters agree, with 1 more left out because at least one datasheet does not publish it. Two records this alike are usually one panel sold under two names, or two bins of the same production line - decide on price and on who you would rather buy from. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [GCL GCL-NT12/66GDF-725](https://comparepv.com/panel/gcl-gcl-nt12-66gdf-725) | [GCL GCL-NT12/66GDF 725](https://comparepv.com/panel/gcl-gcl-nt12-66gdf-725-1) | | Manufacturer | GCL | GCL | | Power | 725 Wp | 725 Wp | | Efficiency | 23.34 % | 23.34 % | | Technology | TOPCon | TOPCon | ## Every compared parameter | Parameter | 66GDF-725 | 66GDF 725 | | --- | --- | --- | | Rated power | 725 Wp | 725 Wp | | Module efficiency | 23.34 % | 23.34 % | | Power density | 233.4 Wp/m² | 233.4 Wp/m² | | Open-circuit voltage | 48.80 V | 48.80 V | | Voltage at max power | 41.03 V | 41.03 V | | Short-circuit current | 18.60 A | 18.60 A | | Current at max power | 17.67 A | 17.67 A | | Temperature coefficient | -0.290 %/°C | -0.290 %/°C | | Dimensions | 2384x1303x33 mm | 2384x1303x33 mm | | Module area | 3.106 m² | 3.106 m² | | Weight | 38.2 kg | 38.3 kg | | Weight per kWp | 52.7 kg/kWp | 52.8 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | - | | Cell technology | TOPCon | TOPCon | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 132 | | Bifacial | Yes | Yes | ## Thirty-year yield A 1.0% first-year loss then 0.40% a year, assumed for both panels, 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, 66GDF-725:** 24,325 kWh - **Cumulative output, 66GDF 725:** 24,325 kWh - **Gap:** No difference ## Output when hot | Condition | Cell temperature | 66GDF-725 | 66GDF 725 | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 725 W | 725 W | 100.0% of rated power | | Cool, bright day | 40 °C | 693 W | 693 W | 95.7% of rated power | | Typical summer roof | 55 °C | 662 W | 662 W | 91.3% of rated power | | Hot roof | 70 °C | 630 W | 630 W | 87.0% of rated power | ## Against the whole database | Measure | 66GDF-725 | 66GDF 725 | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #943 | #943 | 14,005 | Tied - the same position in the database | | Power density | #936 | #936 | 14,005 | Tied - the same position in the database | | Heat behaviour | #2,165 | #2,165 | 14,005 | Tied - the same position in the database | | Weight | #6,337 | #6,514 | 14,005 | 66GDF-725 leads by 177 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #403 | #403 | 14,005 | Tied - the same position in the database | ## Questions ### Which panel is better: GCL GCL-NT12/66GDF-725 or GCL GCL-NT12/66GDF 725? According to our database: both panels are closely matched on key specs - the decision often comes down to price and local availability. See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of GCL GCL-NT12/66GDF-725 and GCL GCL-NT12/66GDF 725? **GCL GCL-NT12/66GDF-725** has a module efficiency of **23.34%**, while **GCL GCL-NT12/66GDF 725** is **23.34%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does GCL GCL-NT12/66GDF-725 use vs GCL GCL-NT12/66GDF 725? **GCL GCL-NT12/66GDF-725** uses **TOPCon** cells; **GCL GCL-NT12/66GDF 725** 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 GCL GCL-NT12/66GDF-725 and GCL GCL-NT12/66GDF 725? **GCL GCL-NT12/66GDF-725** has a **30 years** power warranty; **GCL GCL-NT12/66GDF 725** 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 GCL GCL-NT12/66GDF-725 and GCL GCL-NT12/66GDF 725 bifacial panels? Both **GCL GCL-NT12/66GDF-725** and **GCL GCL-NT12/66GDF 725** 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 - [GCL GCL-NT12/66GDF-725 vs GCL GCL-NT12/66GDF-740](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-725/gcl-gcl-nt12-66gdf-740) - 3 differences, the largest is module efficiency - [GCL GCL-NT12/66GDF-725 vs GCL GCL-NT12/66GDF-735](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-725/gcl-gcl-nt12-66gdf-735) - 3 differences, the largest is module efficiency - [GCL GCL-NT12/66GDF-725 vs GCL GCL-NT12/66GDF-730](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-725/gcl-gcl-nt12-66gdf-730) - The same specification on paper - [GCL GCL-NT12/66GDF-725 vs GCL NT12/66GDF-730](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-725/gcl-nt12-66gdf-730) - The same specification on paper - [GCL GCL-NT12/66GDF-725 vs GCL NT12/66GDF-725](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-725/gcl-nt12-66gdf-725) - The same specification on paper - [GCL GCL-NT12/66GDF-725 vs GCL GCL-NT12/66GDF-720](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-725/gcl-gcl-nt12-66gdf-720) - The same specification on paper --- Source: https://comparepv.com/compare/gcl-gcl-nt12-66gdf-725/gcl-gcl-nt12-66gdf-725-1 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.