--- title: "GCL GCL-M10/72GDF-B-550 vs GCL GCL-M10/72GDF-B-555 - Solar Panel Comparison | ComparePV" description: "Compare GCL GCL-M10/72GDF-B-550 vs GCL GCL-M10/72GDF-B-555 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-m10-72gdf-b-550/gcl-gcl-m10-72gdf-b-555" updated: 2026-09-11 --- # GCL GCL-M10/72GDF-B-550 vs GCL GCL-M10/72GDF-B-555 Identical on every published parameter All 19 comparable parameters agree. 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-M10/72GDF-B-550](https://comparepv.com/panel/gcl-gcl-m10-72gdf-b-550) | [GCL GCL-M10/72GDF-B-555](https://comparepv.com/panel/gcl-gcl-m10-72gdf-b-555) | | Manufacturer | GCL | GCL | | Power | 550 Wp | 555 Wp | | Efficiency | 21.00 % | 21.10 % | | Technology | PERC | PERC | ## Every compared parameter | Parameter | 550 | 555 | | --- | --- | --- | | Rated power | 550 Wp | 555 Wp | | Module efficiency | 21.00 % | 21.10 % | | Power density | 209.6 Wp/m² | 211.5 Wp/m² | | Open-circuit voltage | 49.80 V | 50.08 V | | Voltage at max power | 41.93 V | 42.18 V | | Short-circuit current | 13.88 A | 13.93 A | | Current at max power | 13.12 A | 13.16 A | | Temperature coefficient | -0.350 %/°C | -0.350 %/°C | | Dimensions | 2290x1146x30 mm | 2290x1146x30 mm | | Module area | 2.624 m² | 2.624 m² | | Weight | 33.2 kg | 33.2 kg | | Weight per kWp | 60.4 kg/kWp | 59.8 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.45 %/yr | 0.45 %/yr | | Cell technology | PERC | PERC | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 144 | 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 (-0.350 %/°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, 550:** 18,112 kWh - **Cumulative output, 555:** 18,277 kWh - **Gap:** 165 kWh ## Output when hot | Condition | Cell temperature | 550 | 555 | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 550 W | 555 W | 100.0% of rated power | | Cool, bright day | 40 °C | 521 W | 526 W | 94.8% of rated power | | Typical summer roof | 55 °C | 492 W | 497 W | 89.5% of rated power | | Hot roof | 70 °C | 463 W | 468 W | 84.2% of rated power | ## Against the whole database | Measure | 550 | 555 | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #9,758 | #9,297 | 14,005 | 555 leads by 461 places | | Power density | #9,926 | #9,200 | 14,005 | 555 leads by 726 places | | Heat behaviour | #10,419 | #10,419 | 14,005 | Tied - the same position in the database | | Weight | #12,444 | #12,297 | 14,005 | 555 leads by 147 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #7,387 | #7,100 | 14,005 | 555 leads by 287 places | ## Questions ### Which panel is better: GCL GCL-M10/72GDF-B-550 or GCL GCL-M10/72GDF-B-555? According to our database: **GCL GCL-M10/72GDF-B-555** has higher module efficiency (**21.10%** vs **21.00%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of GCL GCL-M10/72GDF-B-550 and GCL GCL-M10/72GDF-B-555? **GCL GCL-M10/72GDF-B-550** has a module efficiency of **21.00%**, while **GCL GCL-M10/72GDF-B-555** is **21.10%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does GCL GCL-M10/72GDF-B-550 use vs GCL GCL-M10/72GDF-B-555? **GCL GCL-M10/72GDF-B-550** uses **PERC** cells; **GCL GCL-M10/72GDF-B-555** uses **PERC**. 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-M10/72GDF-B-550 and GCL GCL-M10/72GDF-B-555? **GCL GCL-M10/72GDF-B-550** has a **30 years** power warranty; **GCL GCL-M10/72GDF-B-555** 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-M10/72GDF-B-550 and GCL GCL-M10/72GDF-B-555 bifacial panels? Both **GCL GCL-M10/72GDF-B-550** and **GCL GCL-M10/72GDF-B-555** 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-M10/72GDF-B-550 vs GCL GCL-M10/72GDF-B-545](https://comparepv.com/compare/gcl-gcl-m10-72gdf-b-550/gcl-gcl-m10-72gdf-b-545) - One difference: module efficiency - [GCL GCL-M10/72GDF-B-550 vs GCL GCL-M10/72GDF-B-540](https://comparepv.com/compare/gcl-gcl-m10-72gdf-b-550/gcl-gcl-m10-72gdf-b-540) - 3 differences, the largest is module efficiency - [GCL GCL-M10/72GDF-B-550 vs GCL GCL-M10/72GDF-B-535](https://comparepv.com/compare/gcl-gcl-m10-72gdf-b-550/gcl-gcl-m10-72gdf-b-535) - 3 differences, the largest is module efficiency - [GCL GCL-M10/72GDF-B-550 vs GCL GCL-NT12/66GDF-740](https://comparepv.com/compare/gcl-gcl-m10-72gdf-b-550/gcl-gcl-nt12-66gdf-740) - 13 differences, the largest is module efficiency - [GCL GCL-M10/72GDF-B-550 vs GCL GCL-NT12/66GDF-735](https://comparepv.com/compare/gcl-gcl-m10-72gdf-b-550/gcl-gcl-nt12-66gdf-735) - 13 differences, the largest is module efficiency - [GCL GCL-M10/72GDF-B-550 vs GCL GCL-NT12/66GDF-730](https://comparepv.com/compare/gcl-gcl-m10-72gdf-b-550/gcl-gcl-nt12-66gdf-730) - 13 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/gcl-gcl-m10-72gdf-b-550/gcl-gcl-m10-72gdf-b-555 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.