Middle of its segment, weak in heat
The GCL GCL-M12/60GDF series are bifacial dual-sided modules designed to genuinely increase energy yield in installations where every additional percent of production counts - from large-scale PV farms to demanding agrivoltaic and floating projects. Thanks to the bifacial dual-glass construction, the panels can effectively utilize reflected light from the ground, helping to stabilize energy output under varying conditions and improving the overall profitability of the system.
What sets this series apart is the use of monocrystalline cells in PERC technology and an architecture based on the M12 (G12) format, which supports high cell density and minimizes losses. In practice, this translates to higher energy production on limited surfaces and easier achievement of design goals without adding more modules.
The series has been refined for reliability - notably through PID resistance and solutions that reduce the risk of micro-cracks and hot-spots. For investors, this means fewer service issues, greater predictability of system performance, and better protection of the financial outcome.
Ranking
Signals from the data
Utility-scale, agrivoltaic and floating.
Hot climates.
Bottom 20% of the PERC 600-650 W segment, against a median of -0.340.
The bifacial dual-glass construction enables absorption of irradiance reflected from the ground surface (typical bifacial gain of 5-15% depending on albedo), directly increasing annual energy output compared to monofacial modules. Replacing the rear backsheet with glass also eliminates moisture ingress, reducing the risk of PID and laminate degradation over the long term.
GCL-SI is listed on the Bloomberg NEF Tier 1 index as one of the two largest PV module manufacturers in the world by installed capacity. This status is a prerequisite for non-recourse project finance on utility-scale PV plants and directly lowers the cost of capital for institutional investors.
The manufacturer guarantees power output retention for 30 years, exceeding the 25-year standard offered by several comparable series (e.g., Seraphim Seco). The extended warranty horizon improves DCF models and reduces residual risk for projects with long-tenor financing.
A peak efficiency of 21.6% positions the series on par with the Techwise Summit and Seraphim Seco (both at 21.55%), delivering higher power density per m² and simplifying the achievement of design targets on land-constrained sites.
The 182 mm (M10/M12) cells arranged in a 60-cell half-cut configuration minimize resistive losses and hot-spot risk. In practice, this translates to a higher fill factor and more stable performance under partial shading conditions compared to legacy G1/G6 cell formats.
A 15-year product warranty is becoming the standard in the premium module segment (>590 Wp) - offered by manufacturers such as Vikram Solar SOMERA, among others. The GCL-M12/60GDF is covered for only 12 years, which may serve as a negotiating point when comparing bids in tenders that require longer component protection.
The series is based on P-type PERC cells (Pmax temperature coefficient: -0.35%/°C), while the market is increasingly offering N-type TOPCon modules with lower LID and superior temperature characteristics (typically -0.29 to -0.30%/°C). For projects with a long operational horizon, the difference in degradation can be measurable at the level of several percentage points of energy yield after 25 years.
- At 21.4% efficiency, this panel is on par with typical PERC 600-650W modules
- At 213.8 W/m² power density, roof space requirements are typical for PERC 600-650W panels
- Temperature coefficient of -0.35%/°C matches the PERC 600-650W median
- Bifaciality factor of 70% can add 4-10% extra yield with reflective mounting surface
- In the top 59% for efficiency among all PERC panels
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 605 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 GCL-M12/60GDF series
These answers cover the whole series. Where a figure differs, the specification above is this module's own.