--- title: "GCL GCL-NT12/66GDF-730 vs GCL NT12/66GDF-720 - Solar Panel Comparison | ComparePV" description: "Compare GCL GCL-NT12/66GDF-730 vs GCL NT12/66GDF-720 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-730/gcl-nt12-66gdf-720" updated: 2026-09-11 --- # GCL GCL-NT12/66GDF-730 vs GCL NT12/66GDF-720 GCL-NT12/66GDF-730 leads on the differences that matter The largest is module efficiency: 0.32 pp more efficient. 16 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [GCL GCL-NT12/66GDF-730](https://comparepv.com/panel/gcl-gcl-nt12-66gdf-730) | [GCL NT12/66GDF-720](https://comparepv.com/panel/gcl-nt12-66gdf-720) | | Manufacturer | GCL | GCL | | Power | 730 Wp | 720 Wp | | Efficiency | 23.50 % | 23.18 % | | Technology | TOPCon | TOPCon | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | GCL-NT12/66GDF-730 | NT12/66GDF-720 | Difference | | --- | --- | --- | --- | | Module efficiency | 23.50 % | 23.18 % | +0.32 pp for GCL-NT12/66GDF-730 | | Power density | 235.0 Wp/m² | 231.8 Wp/m² | +3.2 Wp/m² for GCL-NT12/66GDF-730 | | Rated power | 730 Wp | 720 Wp | +10 W for GCL-NT12/66GDF-730 | ## Every compared parameter | Parameter | GCL-NT12/66GDF-730 | NT12/66GDF-720 | | --- | --- | --- | | Rated power | 730 Wp | 720 Wp | | Module efficiency | 23.50 % | 23.18 % | | Power density | 235.0 Wp/m² | 231.8 Wp/m² | | Open-circuit voltage | 49.02 V | 48.58 V | | Voltage at max power | 41.22 V | 40.84 V | | Short-circuit current | 18.64 A | 18.55 A | | Current at max power | 17.71 A | 17.63 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 | 52.3 kg/kWp | 53.2 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 | TOPCon | | 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 (-0.290 %/°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, GCL-NT12/66GDF-730:** 24,493 kWh - **Cumulative output, NT12/66GDF-720:** 24,157 kWh - **Gap:** 336 kWh ## Output when hot | Condition | Cell temperature | GCL-NT12/66GDF-730 | NT12/66GDF-720 | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 730 W | 720 W | 100.0% of rated power | | Cool, bright day | 40 °C | 698 W | 689 W | 95.7% of rated power | | Typical summer roof | 55 °C | 666 W | 657 W | 91.3% of rated power | | Hot roof | 70 °C | 635 W | 626 W | 87.0% of rated power | ## Against the whole database | Measure | GCL-NT12/66GDF-730 | NT12/66GDF-720 | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #716 | #1,424 | 14,005 | GCL-NT12/66GDF-730 leads by 708 places | | Power density | #800 | #1,347 | 14,005 | GCL-NT12/66GDF-730 leads by 547 places | | Heat behaviour | #2,165 | #2,165 | 14,005 | Tied - the same position in the database | | Weight | #5,805 | #7,025 | 14,005 | GCL-NT12/66GDF-730 leads by 1,220 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #312 | #540 | 14,005 | GCL-NT12/66GDF-730 leads by 228 places | ## Questions ### Which panel is better: GCL GCL-NT12/66GDF-730 or GCL NT12/66GDF-720? According to our database: **GCL GCL-NT12/66GDF-730** has higher module efficiency (**23.50%** vs **23.18%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of GCL GCL-NT12/66GDF-730 and GCL NT12/66GDF-720? **GCL GCL-NT12/66GDF-730** has a module efficiency of **23.50%**, while **GCL NT12/66GDF-720** is **23.18%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does GCL GCL-NT12/66GDF-730 use vs GCL NT12/66GDF-720? **GCL GCL-NT12/66GDF-730** uses **TOPCon** cells; **GCL NT12/66GDF-720** 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-730 and GCL NT12/66GDF-720? **GCL GCL-NT12/66GDF-730** has a **30 years** power warranty; **GCL NT12/66GDF-720** 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-730 and GCL NT12/66GDF-720 bifacial panels? Both **GCL GCL-NT12/66GDF-730** and **GCL NT12/66GDF-720** 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-730 vs GCL GCL-NT12/66GDF-740](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-730/gcl-gcl-nt12-66gdf-740) - 3 differences, the largest is module efficiency - [GCL GCL-NT12/66GDF-730 vs GCL GCL-NT12/66GDF-735](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-730/gcl-gcl-nt12-66gdf-735) - The same specification on paper - [GCL GCL-NT12/66GDF-730 vs GCL NT12/66GDF-730](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-730/gcl-nt12-66gdf-730) - The same specification on paper - [GCL GCL-NT12/66GDF-730 vs GCL GCL-NT12/66GDF-725](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-730/gcl-gcl-nt12-66gdf-725) - The same specification on paper - [GCL GCL-NT12/66GDF-730 vs GCL NT12/66GDF-725](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-730/gcl-nt12-66gdf-725) - The same specification on paper - [GCL GCL-NT12/66GDF-730 vs GCL GCL-NT12/66GDF 725](https://comparepv.com/compare/gcl-gcl-nt12-66gdf-730/gcl-gcl-nt12-66gdf-725-1) - The same specification on paper --- Source: https://comparepv.com/compare/gcl-gcl-nt12-66gdf-730/gcl-nt12-66gdf-720 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.