--- title: "Tongwei TWMNF-66HD700 Solar Panel: Specs & Datasheet | ComparePV" description: "Tongwei TWMNF-66HD700 solar panel. Specs: 22.50% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/tongwei-twmnf-66hd700" image: "https://comparepv.com/og/panel/tongwei-twmnf-66hd700.png" updated: 2026-09-11 --- # Tongwei TWMNF-66HD700 Strong in heat, modest efficiency 93 panels in the segment N-type 700-750 W ## Identity - **Manufacturer:** Tongwei - **Model:** TWMNF-66HD700 - **Series:** TWMNF N-type Half-cell Bifacial Module (66) - **Rated power:** 700 W - **Cell technology:** N-type - **Bifacial:** yes ## How it compares Compared against segment N-type 700-750 W (93 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 700 W | 710 W | Weak - bottom 10% | | | Module efficiency | 22.50% | 22.90% | Weak - bottom 3% | 4,281 | | Power density | 225.3 | 228.6 | Weak - bottom 10% | 4,048 | | Temperature coefficient | -0.280 | -0.290 | Strong - top 22% | 1,347 | | Weight (kg) | 37.9 kg | 37.9 kg | Typical | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 22.50% | 22.90% | Weak - bottom 3% | 4,281 | | Power density | 225.3 | 228.6 | Weak - bottom 10% | 4,048 | | Temperature coefficient | -0.280 | -0.290 | Strong - top 22% | 1,347 | | Weight per kWp | 54.1 | 53.4 | Typical | 8,436 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Strengths - **-0.280 %/°C temperature coefficient** - Top 22% of the N-type 700-750 W segment, against a median of -0.290. ### Watch out for - **22.50% module efficiency** - Bottom 3% of the N-type 700-750 W segment, against a median of 22.90%. Ranked 4,281st in the whole database. - **225.3 watts per square metre** - Bottom 10% of the N-type 700-750 W segment, against a median of 228.6. Ranked 4,048th in the whole database. - **Best for:** Utility-scale, commercial, shaded-installations and hot-climate. - **Not ideal for:** Tight roof space and roofs where every square metre has to count. ## Specification ### Electrical - **Rated power (Pmax):** 700 W - **Efficiency:** 22.50 % - **Voltage at Pmax (Vmp):** 40.35 V - **Current at Pmax (Imp):** 17.35 A - **Open-circuit voltage (Voc):** 48.60 V - **Short-circuit current (Isc):** 18.35 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.280 %/degC - **Temperature coefficient of Voc:** -0.240 %/degC - **Temperature coefficient of Isc:** 0.046 %/degC - **NOCT:** 45 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** N-type - **Cell count:** 132 - **Bifacial:** yes - **Bifacial gain:** 25.00 ### Physical - **Length:** 2384 mm - **Width:** 1303 mm - **Thickness:** 33 mm - **Weight:** 37.9 kg - **Area:** 3.11 m2 - **Power density:** 225.3 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:** 612 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 4281 of 14129 | | Power density | 4048 of 14129 | | Temperature coefficient | 1347 of 14129 | | Weight | 8436 of 14129 | | Warranty | 21 of 14129 | ## About this series The TWMNF N-type Half-cell Bifacial Module (66) series represents an advanced solution for investors seeking maximum efficiency per unit area. The **innovative N-type cell technology** used in them effectively eliminates the problem of light-induced degradation (LID), which translates into stable energy production for decades. A key differentiator is the **high bifaciality**, which allows for generating additional yield from reflected radiation, being particularly effective on high-albedo surfaces such as light gravel or bright roof membranes. The use of a **Half-cell structure** in combination with 66 cells optimizes current flow and significantly reduces resistance losses, while also improving the module's resistance to the negative effects of partial shading. These panels solve the problem of limited installation space by offering higher power density than standard market solutions. This series is primarily dedicated to large-scale photovoltaic farms and modern commercial installations, where the lowest levelized cost of energy (LCOE) is key. What sets them apart from the competition is exceptional efficiency in low-light conditions and a **low temperature coefficient**, guaranteeing operational stability and smaller power drops even on hot days. This is a solid foundation for profitable PV systems. ## Notable figures - Efficiency of 22.5% matches the \*\*N-type 700-750W\*\* median - At 225.3 W/m², this panel generates 3.3 W/m² less per unit area than \*\*N-type 700-750W\*\* median (228.6 W/m²) - Temperature coefficient of -0.28%/°C matches the \*\*N-type 700-750W\*\* median - Bifaciality factor of 80% can add 4-12% extra yield with reflective mounting surface - Ranked #4281 out of 14129 panels for efficiency in the database ## Questions ### What is N-type cell technology used in Tongwei TWMNF panels, and why does it eliminate LID degradation? N-type cells use phosphorus-doped silicon instead of boron, so they do not form the boron-oxygen complexes responsible for light-induced degradation (LID). In practice, this means the TWMNF module does not lose significant power in the first months of operation, and energy output stays stable throughout the entire 30-year power warranty period. N-type technology also delivers higher initial efficiency, reaching up to 23.5%. ### How much extra energy can the bifacial TWMNF-66 panels generate from reflected sunlight? With a bifaciality factor of 80±5%, TWMNF-66 modules also generate current from the rear side using light reflected off the ground surface. Depending on the albedo of the mounting surface - such as light gravel, a white roofing membrane, or snow - the additional energy yield can range from a few to over ten percent compared to an equivalent monofacial panel of the same rated power. ### What warranty does Tongwei offer on the TWMNF N-type Half-cell Bifacial (66) module series? Tongwei backs the TWMNF series with a standard 12-year product warranty as a Tier 1 PV manufacturer headquartered in China. The panels also come with a 30-year linear power warranty, guaranteeing a minimum energy output level throughout the system's operating life. This is a typical standard for premium-class N-type modules designed for long-term use in commercial installations and utility-scale PV farms. ### Are Tongwei TWMNF-66 panels suitable for residential installations, or are they mainly for solar farms? The TWMNF-66 series, with its half-cell design and power up to 700 Wp, is optimized primarily for large-scale PV farms and commercial installations, where low LCOE and high power density per unit area are key priorities. In residential settings, it works best where a sufficiently large and sturdy mounting surface is available, such as large commercial roofs or agricultural land. ### How do TWMNF-66 panels perform in summer under high roof temperatures? TWMNF-66 modules have a low power temperature coefficient of around -0.28%/°C, an improvement over classic P-type PERC panels. This means a smaller power drop on hot days when panel temperature can exceed 60°C. The module's operating range spans from -40°C to +85°C, confirming its stability even under extreme climate conditions. ### What does the half-cell structure with 66 cells mean, and how does it improve shading tolerance? The half-cell design cuts standard cells in half, giving the TWMNF-66 module effectively 132 smaller cells connected across two independent circuits. This layout reduces resistive current losses and limits the impact of shading a single cell on the entire string - so if part of the panel is shaded, for example by a chimney or antenna, only that section loses power rather than the whole module. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/3c6bad1bd8d93f84f16a059207c90605-7f160493bcb6.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | -50 W, lighter, +2.7 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | Cooler, lighter, +2.7 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | -25 W, lighter, +2.5 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | Cooler, lighter, +2.5 pp | | [WINAICO WST-675BKX72-A2](https://comparepv.com/panel/winaico-wst-675bkx72-a2) | 675 W | -25 W, lighter, +2.5 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | Cooler, lighter, +2.4 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | -30 W, lighter, +2.3 pp | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | -30 W, lighter, +2.3 pp | | [Tongwei TWMPF-66HD655](https://comparepv.com/panel/tw-solar-tongwei-twmpf-66hd655) | 655 W | -45 W, hotter, -1.4 pp | | [Tongwei TWMPF-66HD660](https://comparepv.com/panel/tw-solar-tongwei-twmpf-66hd660) | 660 W | -40 W, hotter, -1.3 pp | | [Tongwei TWMPF-66HD665](https://comparepv.com/panel/tw-solar-tongwei-twmpf-66hd665) | 665 W | -35 W, hotter, -1.1 pp | | [Tongwei TWMPF-66HD670](https://comparepv.com/panel/tw-solar-tongwei-twmpf-66hd670) | 670 W | -30 W, hotter, -0.9 pp | | [Tongwei TWMPF-66HD675](https://comparepv.com/panel/tw-solar-tongwei-twmpf-66hd675) | 675 W | -25 W, hotter, -0.8 pp | | [Tongwei TWMNF-66HD705](https://comparepv.com/panel/tongwei-solar-twmnf-66hd705) | 705 W | Very close match | | [AIKO AIKO-A805-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a805-grh78dw) | 805 W | +105 W, cooler, +2.6 pp | | [AIKO AIKO-A800-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a800-grh78dw) | 800 W | +100 W, cooler, +2.4 pp | --- Source: https://comparepv.com/panel/tongwei-twmnf-66hd700 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.