2025.08.29
1. Polycrystalline Silicon Photovoltaic Panels (P-Type, Traditional Low-End)
l Technical Principle: Silicon material is made into polycrystalline silicon ingots through the "ingot casting method," which are then cut into wafers. The crystal structure is composed of multiple, chaotically arranged small single crystals, which easily hinders electron movement and results in low efficiency.
l Appearance: Blue panel with a distinct "snowflake/ice flower" pattern on the surface (a visual indicator of the polycrystalline structure), and mostly square edges (rounded corners were also present in earlier versions).
l Core Performance:
Conversion Efficiency: 15%-17% (currently the lowest among mainstream options, gradually being phased out);
Light-Induced Degradation (LID): Significant (3%-5% degradation in the first year);
Temperature Coefficient: Poor (efficiency drops significantly at high temperatures, approximately -0.45%/°C);
Lifespan: 25 years (but efficiency decays rapidly later in life).
l Applications: Early-stage small residential and low-end industrial and commercial projects. Currently, very few new projects use this technology (only existing projects are used for maintenance).
2. Monocrystalline Silicon Photovoltaic Panels (P-Type, Traditional Mainstream)
l Technical Principle: Silicon material is produced through the Czochralski (CZ) process into monocrystalline silicon rods, which are then cut into wafers. The resulting crystal structure is a "complete, continuous single crystal," resulting in minimal resistance to electron movement and higher efficiency than polycrystalline.
l Appearance: Dark blue/pure black panel (due to advances in surface coating technology, "black silicon" has become more popular in recent years), edges are mostly "rounded rectangles" (as opposed to the square shape of polycrystalline), and the surface is unpatterned (the monocrystalline structure is uniform).
l Core Performance:
Conversion Efficiency: 18%-22% (currently the mainstream "basic" efficiency for residential, commercial, and industrial projects);
Light-Induced Degradation (LID): Valid, but mild (2%-3% degradation in the first year);
Temperature Coefficient: Moderate (approximately -0.40%/°C, more stable than polycrystalline at high temperatures);
Lifespan: 25-30 years (smooth degradation curve, stable power generation over the remaining years).
l Scenario: Distributed residential photovoltaic (the largest share), small and medium-sized commercial and industrial power plants, and some ground-mounted power plants (striving for a balance between cost and efficiency).
3. N-type TOPCon photovoltaic panel (new generation, high-efficiency, currently the mainstream upgrade)
TOPCon stands for "Tunnel Oxide Passivated Contact" and is a direct upgrade technology for P-type monocrystalline silicon. Its core technology involves adding a "tunnel oxide layer + polysilicon layer" to the silicon wafer surface to reduce electron recombination losses.
l Technical Principle: Based on N-type silicon wafers, the "passivated contact" structure improves carrier lifetime—electrons experience less loss as they move within the silicon wafer, resulting in higher efficiency and addressing the LID problem at its root.
l Appearance: Similar to P-type monocrystalline (dark blue/pure black, rounded rectangle), difficult to distinguish based on appearance alone; refer to the product specifications.
l Core Performance:
Conversion Efficiency: 23%-26% (mass production efficiency has generally exceeded 24%, and laboratory efficiency has exceeded 28%);
Light-Induced Degradation (LID): Almost no degradation (less than 1% degradation in the first year, with extremely strong long-term stability);
Temperature Coefficient: Excellent (approximately -0.30% to -0.35%/°C, with significant advantages in high-temperature regions);
Weak-Light Performance: Good (5%-10% more power generation than P-type in the early morning, evening, and on cloudy days).
l Applications: Distributed home use (for high power generation), large-scale ground-mounted power stations (recommended for lower cost per kilowatt-hour), and high-temperature/high-irradiation regions (such as Northwest and South China).
4. N-Type HJT Photovoltaic Panels (Next-Generation High-Efficiency, High-End Alternative)
HJT stands for "Heterojunction with Intrinsic Thin-Layer Photovoltaic Cells." Its technology differs from TOPCon, featuring a heterojunction structure of "crystalline silicon + amorphous silicon," which provides superior passivation.
l Technical Principle: An intrinsic amorphous silicon layer (intrinsic layer) and a doped amorphous silicon layer (P-type/N-type) are deposited on either side of an N-type monocrystalline silicon wafer, forming a heterojunction. The intrinsic layer significantly reduces electron-hole recombination, resulting in a higher open-circuit voltage and a higher efficiency ceiling than TOPCon.
l Appearance: Pure black (the amorphous silicon layer is deposited more evenly, resulting in a more refined visual effect). Some products are capable of "bifacial" power generation (both the front and back sides absorb light). The thickness is thinner than traditional photovoltaic panels (approximately 200μm, making them more lightweight).
l Core Performance:
Conversion Efficiency:24%-27% (mass production efficiency slightly higher than TOPCon, laboratory efficiency exceeding 29%, the current efficiency ceiling for crystalline silicon cells);
Light-Induced Degradation (LID): No degradation (excellent passivation of the amorphous silicon layer, providing optimal long-term stability);
Temperature Coefficient: Optimal (approximately -0.25% to -0.30%/°C, minimizing power loss at high temperatures);
Weak-Light Performance: Optimal (the amorphous silicon layer has strong absorption of weak light, resulting in 3%-5% more power generation than TOPCon on cloudy days/early mornings).
l Applications: High-end residential distributed systems (pursuing ultimate aesthetics and energy yield), commercial and industrial projects with limited rooftop loads (lightweight and thin to reduce roof load), areas with unstable sunlight (such as the rainy south), and BIPV (Building Integrated Photovoltaic, suitable for photovoltaic curtain walls and photovoltaic tiles).
Keywords：
Sun Earth Solar, Ningbo Sun Earth, Sun-Earth, Sun Earth, Photovoltaic Panels, N-Type Module, Topcon Module
