--- title: "GCL GCL-NT10/78GDF-665 Solar Panel: Specs & Datasheet | ComparePV" description: "GCL GCL-NT10/78GDF-665 solar panel. Specs: 23.79% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/gcl-gcl-nt10-78gdf-665" image: "https://comparepv.com/og/panel/gcl-gcl-nt10-78gdf-665.png" updated: 2026-09-11 --- # GCL GCL-NT10/78GDF-665 Solid all-round for its segment 254 panels in the segment TOPCon 650-700 W ## Identity - **Manufacturer:** GCL - **Model:** GCL-NT10/78GDF-665 - **Series:** GCL-NT10/78GDF - **Rated power:** 665 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) | 665 W | 665 W | Typical | | | Module efficiency | 23.79% | 22.40% | Typical | 529 | | Power density | 237.9 | 223.7 | Typical | 495 | | 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 | 23.79% | 22.40% | Typical | 529 | | Power density | 237.9 | 223.7 | Typical | 495 | | Temperature coefficient | -0.290 | -0.290 | Typical | 2,220 | | Weight per kWp | 50.5 | 53.1 | Typical | 3,913 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | - **Best for:** Utility-scale, commercial and hot-climate. ## Specification ### Electrical - **Rated power (Pmax):** 665 W - **Efficiency:** 23.79 % - **Voltage at Pmax (Vmp):** 49.63 V - **Current at Pmax (Imp):** 13.40 A - **Open-circuit voltage (Voc):** 58.13 V - **Short-circuit current (Isc):** 14.15 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:** 237.9 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:** 581 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 529 of 14129 | | Power density | 495 of 14129 | | Temperature coefficient | 2220 of 14129 | | Weight | 3913 of 14129 | | Warranty | 21 of 14129 | ## Pros - **N-type TOPCon cells, up to 23.79% efficiency** - The use of N-type TOPCon monocrystalline cells delivers efficiency in the 22.9-23.79% range, clearly above typical PERC modules (~21-22%) and comparable to Waaree's ARKA series (21.29%), translating into higher yield per unit of roof or ground area. - **Bifacial design with dual-glass construction** - Bifacial glass-glass modules capture light reflected from the ground, providing additional energy yield under suitable installation conditions (light-colored surface, ventilation), while the dual-glass build improves mechanical durability and extends service life compared to glass-backsheet designs. - **30-year linear power warranty** - The 30-year power warranty is a premium standard in the TOPCon segment and enables more precise LCOE calculations for ground-mount and utility-scale PV projects, where predictable long-term energy production is critical. - **BNEF Tier-1 bankability** - GCL System Integration is recognized as a Tier 1 manufacturer by BloombergNEF (Q2 2026 rankings), meaning access to non-recourse financing and lower risk for investors and EPCs executing large ground-mount projects. - **Environmental certifications for harsh conditions** - Resistance to PID, salt mist, ammonia, and sand/dust makes the series suitable for ground-mount installations in industrial, agricultural, and coastal environments, where standard modules may show accelerated degradation. ## Cons - **Efficiency trails segment leaders** - Maximum efficiency of 23.79% is lower than comparable 665 Wp Tier 1 models - Sunpro Power SPDG-BC132R12 (24.62%) and Talesun CIPRO-TM9C72M (24.6%) - meaning roughly 3-4% lower power output per module for the same roof area. ## About this series The GCL GCL-NT10/78GDF series is designed for installations where the maximum energy yield from the same surface area is crucial - especially for large ground-mounted projects and PV farms. The use of **N-type TOPCon monocrystalline cells** translates to high efficiency in real-world conditions and more stable long-term performance, which is key when calculating LCOE. These are **bifacial** modules, so they can utilize reflected light from the ground - in practice, this means additional yield where appropriate conditions are met (e.g., light pavement, good ventilation, optimal row spacing). The **dual glass** construction helps better withstand mechanical stresses and demanding operating environments, and the certification includes, among others, resistance to **anti-PID**, salt fog, ammonia, and dust and sand. The NT10/78GDF series will be an excellent choice for investors, EPCs, and business consumers who want to reduce degradation risk and rely on predictable energy production over the long term. ## Notable figures - At 23.8% efficiency, this panel is 1.4pp above typical \*\*TOPCon 650-700W\*\* modules (median: 22.4%) - At 237.9 W/m² power density, this panel generates 14.2 W/m² more per unit area than \*\*TOPCon 650-700W\*\* median (223.7 W/m²) - At -0.29%/°C, hot weather performance is typical for \*\*TOPCon 650-700W\*\* panels - 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 is the maximum power output of the GCL GCL-NT10/78GDF panel? The highest power variant in the GCL-NT10/78GDF series reaches 665 Wp. This output is achieved through N-type TOPCon monocrystalline cells with high efficiency combined with a bifacial design that further boosts energy yield. Higher unit power means fewer modules are needed to reach a target system capacity, reducing racking and installation labor costs. ### How does the bifacial GCL-NT10/78GDF differ from a standard monofacial panel? The bifacial GCL-NT10/78GDF captures sunlight on both the front and rear sides of the module, generating additional energy from light reflected off the ground surface. In practice this means higher energy yield from the same installation area, especially over light-colored ground, with elevated mounting, or wider row spacing. The dual glass construction also improves mechanical durability compared to standard backsheet panels. ### What warranty comes with the GCL-NT10/78GDF panels? The manufacturer provides a 12-year product warranty and a 30-year linear power performance warranty. This means the panel is expected to keep producing energy at a guaranteed, predictable level after three decades of operation. This warranty horizon matters for LCOE calculations in utility-scale PV projects, where long-term production stability drives investment profitability. ### Is GCL a tier 1 manufacturer and where are the NT10/78GDF panels made? Yes, GCL is classified as a tier 1 manufacturer, reflecting strong financial standing, large-scale production, and years of experience in the PV industry. The company is headquartered in China and is one of the global leaders in cell and module manufacturing, including N-type TOPCon technology. Tier 1 status matters for bank financing of projects, as lenders are more willing to finance installations using components from established, large-scale manufacturers. ### What type of installation is the GCL-NT10/78GDF series best suited for? The NT10/78GDF series is primarily designed for large ground-mounted installations and utility-scale PV farms, where maximizing energy yield per unit of land area is critical. Thanks to its bifacial and dual glass design, the module performs well on elevated racking structures with a light-colored ground surface. It's mainly targeted at investors, EPC contractors, and commercial prosumers rather than typical residential rooftop installations. ### Are the GCL-NT10/78GDF panels resistant to harsh environmental conditions, such as coastal sites? Yes, panels in this series are certified for resistance to PID, salt mist, ammonia, and dust and sand exposure. Salt mist resistance is particularly important for coastal installations, where salty air accelerates component corrosion, while ammonia resistance matters for sites near agricultural or livestock facilities. The dual glass construction further enhances the module's mechanical durability in demanding operating environments. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/1785317296379879-7f87dfef61aa.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, lighter, +1.4 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | Cooler, lighter, +1.4 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | Cooler, lighter, +1.2 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +1.2 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +35 W, cooler, +1.2 pp | | [WINAICO WST-675BKX72-A2](https://comparepv.com/panel/winaico-wst-675bkx72-a2) | 675 W | Cooler, lighter, +1.2 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +30 W, cooler, +1.1 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | Cooler, lighter, +1.0 pp | | [GCL GCL-NT10/78GDF-630](https://comparepv.com/panel/gcl-gcl-nt10-78gdf-630) | 630 W | -35 W, -1.2 pp | | [GCL GCL-NT10/78GDF-635](https://comparepv.com/panel/gcl-gcl-nt10-78gdf-635) | 635 W | -30 W, -1.1 pp | | [GCL GCL-NT10/78GDF-640](https://comparepv.com/panel/gcl-gcl-nt10-78gdf-640) | 640 W | -25 W, -0.9 pp | | [GCL GCL-NT10/78GDF-645](https://comparepv.com/panel/gcl-gcl-nt10-78gdf-645) | 645 W | -20 W, -0.7 pp | | [GCL GCL-NT10/78GDF-650](https://comparepv.com/panel/gcl-gcl-nt10-78gdf-650) | 650 W | -15 W, -0.5 pp | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | Cooler, lighter, +1.0 pp | | [Jinko Solar JKM650-670N-66QL6-BDV (670W class)](https://comparepv.com/panel/jinko-solar-jkm650-670n-66ql6-bdv-670w-class) | 670 W | Cooler, lighter, +1.0 pp | --- Source: https://comparepv.com/panel/gcl-gcl-nt10-78gdf-665 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.