--- title: "GCL NT10/78GDF-655W Solar Panel: Specs & Datasheet | ComparePV" description: "GCL NT10/78GDF-655W solar panel. Specs: 23.43% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/gcl-nt10-78gdf-655w" image: "https://comparepv.com/og/panel/gcl-nt10-78gdf-655w.png" updated: 2026-09-11 --- # GCL NT10/78GDF-655W Solid all-round for its segment 254 panels in the segment TOPCon 650-700 W ## Identity - **Manufacturer:** GCL - **Model:** NT10/78GDF-655W - **Series:** NT10/78GDF - **Rated power:** 655 W - **Cell technology:** TOPCon - **Bifacial:** yes ## How it compares Compared against segment TOPCon 650-700 W (254 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 655 W | 665 W | Typical | | | Module efficiency | 23.43% | 22.40% | Typical | 900 | | Power density | 234.3 | 223.7 | Typical | 894 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,220 | | Weight (kg) | 33.6 kg | 34.6 kg | Typical | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 23.43% | 22.40% | Typical | 900 | | Power density | 234.3 | 223.7 | Typical | 894 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,220 | | Weight per kWp | 51.3 | 53.1 | Typical | 4,706 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | - **Best for:** Utility-scale, commercial and hot-climate. ## Specification ### Electrical - **Rated power (Pmax):** 655 W - **Efficiency:** 23.43 % - **Voltage at Pmax (Vmp):** 49.25 V - **Current at Pmax (Imp):** 13.30 A - **Open-circuit voltage (Voc):** 57.68 V - **Short-circuit current (Isc):** 14.05 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:** 0.045 %/degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** TOPCon - **Cell count:** 156 - **Bifacial:** yes ### Physical - **Length:** 2465 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 33.6 kg - **Area:** 2.80 m2 - **Power density:** 234.3 Wp/m2 ### Warranty and degradation - **Product warranty:** 12 years - **Performance warranty:** 30 years - **Output guaranteed at end of warranty:** 87.4 % - **First-year degradation:** 1.00 % - **Annual degradation:** 0.40 % - **Output after 30 years:** 572 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 900 of 14129 | | Power density | 894 of 14129 | | Temperature coefficient | 2220 of 14129 | | Weight | 4706 of 14129 | | Warranty | 21 of 14129 | ## Pros - **Low Temperature Coefficient of Pmax** - N-type TOPCon technology delivers a Pmax temperature coefficient of -0.29%/°C (GCL NT10/78GDF datasheet), which is notably superior to typical PERC panels that reach -0.34-0.35%/°C. For a 1 MWp installation in the Polish climate, this translates to a realistically higher summer energy yield of approximately 1-2% per year compared to older technologies. - **30-Year Power Warranty at ≥87.4%** - GCL guarantees a minimum of 87.4% of nominal power output after 30 years of operation, exceeding the industry-standard threshold of 84.8% commonly applied in the sector. For a 5 MWp PV plant, this difference translates to several additional MWh per year in the final years of operation, materially improving project IRR. - **Bifacial Dual Glass - Confirmed Rear-Side Gain** - The dual glass construction with N-type bifacial cells enables rear-side energy yield of up to 25-30% relative to the front side (per manufacturer data and IEC TS 60904-1-2), which in ground-mounted installations over high-albedo surfaces (gravel, concrete, snow) significantly increases annual energy production with no increase in material costs. - **Mechanical Load Rating of 3,600/1,600 Pa** - The allowable load of 3,600 Pa on the front side and 1,600 Pa on the rear side (GCL NT10/78GDF datasheet, ManualsLib) places this module among the top-rated for mechanical resistance in the >630 Wp segment, qualifying it for installation in climatic zones with heavy snowfall (zones III-IV per PN-EN 1991-1-3) without the need for a denser racking structure. - **BNEF Tier 1 Manufacturer - Bankability Confirmed** - GCL System Integration appears on the BNEF Tier 1 solar module list for Q1 2026 (BNEF Tier 1 Solar Module Methodology, March 2026) and is ranked #2 globally by annual module shipment capacity. Bankable status is a key requirement for non-recourse project financing of PV plants and streamlines lender due diligence. ## Cons - **Max. Efficiency 23.43% vs. Segment Leader at 24.2%** - The Tongwei TWMNH-66HD (a direct peer comparable at the same 655 Wp power class) achieves 24.2% efficiency-0.77 percentage points higher than the maximum value of the GCL NT10/78GDF (23.43%). For projects with constrained roof or land area, such as an industrial rooftop, this means approximately 3.4% more GCL modules would be required to achieve the same installed capacity. - **Product Warranty of Only 12 Years** - The product warranty is 12 years, whereas several premium manufacturers in this segment-including Jinko Tiger Neo and LONGi Hi-MO 7-offer 15-year product warranties. For projects financed by institutions that require a product warranty of ≥15 years as a condition of insurance or financing, this may necessitate additional coverage in the form of performance bonds or warranty insurance policies. ## About this series The GCL NT10/78GDF series introduces a new quality to large-scale energy installations thanks to the use of advanced **N-type TOPCon technology**. Replacing traditional solutions with N-type cells allows for a significant reduction in LID and LeTID light degradation, directly addressing the issue of performance decline in the initial years of system operation. Through the use of an innovative **bifacial dual glass** structure, these panels effectively utilize light reflected from the ground, generating noticeably more energy even at a low solar angle. These modules are primarily dedicated to professional investors building solar farms and large commercial facilities, where maximizing yield from limited land or roof space is key. Exceptional **resistance to extreme mechanical loads** and an excellent temperature coefficient ensure this series outperforms standard products in terms of operational stability during summer heat. The use of a larger cell format results in a real reduction in BOS installation costs, which significantly shortens the payback period for the entire investment. By choosing this model, the investor gains the assurance of **maximum system longevity** and effective protection against micro-cracks, guaranteeing stable power production and failure-free operation for many decades. ## Notable figures - Efficiency of 23.4% is 1.0pp above the \*\*TOPCon 650-700W\*\* median (22.4%) - At 234.3 W/m² power density, this panel generates 10.6 W/m² more per unit area than \*\*TOPCon 650-700W\*\* median (223.7 W/m²) - Temperature coefficient of -0.29%/°C matches the \*\*TOPCon 650-700W\*\* median - At 33.6 kg, weight matches the \*\*TOPCon 650-700W\*\* median - 80% bifaciality enables rear-side power generation, boosting yield by 4-12% on reflective surfaces ## Questions ### What warranty covers the GCL NT10/78GDF series panels and what does it include? The GCL NT10/78GDF series comes with a 12-year product warranty against manufacturing defects and a 30-year linear power output warranty. In practical terms, after the first year the module will retain at least 99% of its nominal power, and after 30 years of operation it will still produce a minimum of 87.4% of the declared rated power. This places the NT10/78GDF among the best-warranted utility-scale modules currently available on the market. ### Does the TOPCon technology in the GCL NT10/78GDF series offer a real advantage over standard PERC panels? Yes, the difference is tangible. The N-type TOPCon cells used in the NT10/78GDF series exhibit significantly lower LID and LeTID degradation rates compared to P-type PERC cells. This translates into a smaller power loss during the first months of operation and a higher energy yield over the entire system lifetime. The power temperature coefficient is only -0.29%/°C, providing a real performance edge during summer heat compared to typical PERC modules rated at -0.35%/°C. ### How does the bifacial design of the GCL NT10/78GDF panels work, and when does it make sense to choose it? The bifacial dual-glass construction allows the module to capture solar irradiance from both the front glass and the rear glass, which collects diffuse and ground-reflected radiation. The rear-side gain depends on the albedo of the surface beneath the array. The greatest benefits are achieved in ground-mounted systems over bright soil, gravel, or snow, as well as on flat rooftops with light-colored membranes. Under favorable conditions, the additional energy yield from the rear side can reach several to more than ten percent. ### Are the 655 W GCL NT10/78GDF panels suitable for a commercial rooftop installation on an industrial building? Yes, the NT10/78GDF series is specifically designed for large commercial and industrial installations. The module's dimensions of 2465 × 1134 × 30 mm and a weight of approximately 33.6 kg require a properly engineered mounting structure; however, its certified mechanical resistance to wind and snow loads (up to 3,600 Pa front-side and 1,600 Pa rear-side) ensures safe operation even in demanding climatic conditions. The large-format cell design also reduces balance-of-system (BoS) costs per installed kilowatt. ### How does the GCL NT10/78GDF series perform at high temperatures during summer? With a power temperature coefficient of -0.29%/°C, the NT10/78GDF series loses less efficiency during heat waves than the majority of PERC-based modules. For example, at a module surface temperature of 65°C the power loss amounts to approximately 10.4%, whereas a typical PERC panel would lose more than 12% under the same conditions. Across an entire photovoltaic power plant, this difference translates into a measurable additional energy yield during the hottest months of the year. ### Is GCL, as the manufacturer of the NT10/78GDF panels, a reliable partner and can the warranty obligations realistically be fulfilled? GCL System Integration (GCLSI) is classified as a Tier 1 manufacturer by BloombergNEF, confirming its financial stability and demonstrated ability to honor long-term warranty commitments. The company is one of the world's largest producers of photovoltaic wafers and modules, with a sustained presence in European and global markets. For investors developing utility-scale PV farms, this classification is a key consideration when selecting a module supplier and assessing long-term project bankability. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/EN-NT1078GDF_10-J2-cf9d045f0072.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, lighter, +1.8 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | Cooler, lighter, +1.8 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | Cooler, lighter, +1.6 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +1.6 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +45 W, cooler, +1.6 pp | | [WINAICO WST-675BKX72-A2](https://comparepv.com/panel/winaico-wst-675bkx72-a2) | 675 W | +20 W, cooler, +1.6 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +40 W, cooler, +1.5 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | Cooler, lighter, +1.4 pp | | [GCL GCL-NT10/78GDF-630](https://comparepv.com/panel/gcl-gcl-nt10-78gdf-630) | 630 W | -25 W, -0.9 pp | | [GCL GCL-NT10/78GDF-635](https://comparepv.com/panel/gcl-gcl-nt10-78gdf-635) | 635 W | -20 W, -0.7 pp | | [GCL GCL-NT10/78GDF-640](https://comparepv.com/panel/gcl-gcl-nt10-78gdf-640) | 640 W | -15 W, -0.5 pp | | [GCL GCL-NT10/78GDF-645](https://comparepv.com/panel/gcl-gcl-nt10-78gdf-645) | 645 W | -10 W, -0.4 pp | | [GCL GCL-NT10/78GDF-650](https://comparepv.com/panel/gcl-gcl-nt10-78gdf-650) | 650 W | Very close match | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | Cooler, lighter, +1.4 pp | | [Jinko Solar JKM650-670N-66QL6-BDV (670W class)](https://comparepv.com/panel/jinko-solar-jkm650-670n-66ql6-bdv-670w-class) | 670 W | +15 W, cooler, +1.4 pp | --- Source: https://comparepv.com/panel/gcl-nt10-78gdf-655w 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.