Solid all-round for its segment
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.
Ranking
Signals from the data
Utility-scale, commercial and hot-climate.
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.
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.
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.
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.
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.
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.
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.
- 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
Specifications
Datasheet charts
Measured curves published by GCL in this model's datasheet. A chart carrying a wattage was measured on that variant alone - only the ones that describe 655 Wp appear here. The rest cover the whole series.
Simulations
Degradation from this panel's own datasheet figures. No inverter, soiling or shading losses.
Model: bifaciality × albedo × 0.6 view factor. A first-order estimate, not a yield simulation.
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About the NT10/78GDF series
These answers cover the whole series. Where a figure differs, the specification above is this module's own.