Tongwei Solar Panels Calculator
Top-5 global panel manufacturer 2024–2026. Select TW Solar HJT 700W (23.5% flagship), TOPCon 605W, Hi-Wing 580W, or Bifacial Dual-Glass 660W — get panel count, 30-year production, temperature coefficient, and ITC savings.
How to Use This Calculator
Select your Tongwei Solar panel model
Tongwei Solar (TW Solar) offers four distinct panel lines for 2024–2026. The HJT 700W is the 2026 flagship with industry-leading 23.5% efficiency and the lowest temperature coefficient of any mass-production panel (-0.24%/°C). The TOPCon 605W is the high-value residential choice. The Hi-Wing 580W uses a half-cut cell design that reduces hot-spot risk and improves shading tolerance. The Bifacial Dual-Glass 660W is engineered for ground mounts and agrivoltaic installations where rear-side light adds 5–15% free production.
System size, peak sun hours, and installation type
Enter your target system size in kW. The calculator computes the exact panel count needed for your selected model. Peak sun hours (PSH) are equivalent full-sun hours — not total daylight. Commercial installations get a 10–15% reduction in $/W pricing and MACRS 5-year accelerated depreciation on top of the 30% ITC, which dramatically improves commercial economics. Tongwei's competitive pricing at $2.10–2.70/W makes them a compelling value-tier choice without sacrificing performance specs.
Reading the results
Beyond panel count and system cost, pay close attention to the temperature coefficient and hot-day output loss. Tongwei's HJT technology at -0.24%/°C loses only 8.4% power at 60°C panel temperature — compared to 12.25% for standard P-type PERC panels. In hot climates (Arizona, California, Texas), this efficiency advantage compounds into thousands of extra kWh per year.
The Formula
The 0.80 system derating factor represents real-world losses from inverter efficiency, wiring resistance, temperature derating, and soiling — standard across the industry. Bifacial panels include a 1.09 rear-gain multiplier appropriate for ground-mount systems with moderate ground albedo. TW Solar's 30-year performance warranty (0.30–0.40%/yr degradation) means panels at year 30 still produce 89–91% of rated output — well above the industry minimum.
Example
James — 10 kW TW Solar HJT 700W, residential, Phoenix AZ
James has a south-facing roof and wants maximum production from a 10 kW system. He's in Phoenix with 6.5 PSH and pays $0.13/kWh.
Results
James needs only 15 panels to hit 10 kW with the 700W HJT — compared to 18 panels for a 580W model. Fewer panels means fewer roof penetrations, simpler racking, and lower installation labor. In Phoenix's heat, the HJT's -0.24%/°C temperature coefficient means 8.4% power loss on hot days vs. 12.25% for PERC — a measurable production advantage that compounds over 30 years.
Tongwei Solar Model Comparison
| Spec | HJT 700W | TOPCon 605W | Hi-Wing 580W | Bifacial 660W |
|---|---|---|---|---|
| Technology | HJT | N-type TOPCon | N-type TOPCon | TOPCon Bifacial |
| Efficiency | 23.5% | 22.7% | 22.5% | 22.9% |
| Temp coefficient | -0.24%/°C | -0.30%/°C | -0.30%/°C | -0.30%/°C |
| Degradation/yr | 0.30% | 0.40% | 0.40% | 0.40% |
| $/W | $2.70 | $2.40 | $2.25 | $2.55 |
| Performance warranty | 30 yr | 30 yr | 30 yr | 30 yr |
FAQ
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