--- title: "Tongwei TWMNF-66HD740 740W Solar Panel - Specs & Review | ComparePV" description: "Tongwei TWMNF-66HD740 740W solar panel. Specs: 23.80% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/tongwei-solar-twmnf-66hd740" updated: 2026-09-11 --- # Tongwei TWMNF-66HD740 Space saver, no clear weak spot 420 panels in the segment TOPCon 700-750 W ## Identity - **Manufacturer:** Tongwei - **Model:** TWMNF-66HD740 - **Series:** TNC 2.0 TWMNF-66HD - **Rated power:** 740 W - **Cell technology:** TOPCon - **Bifacial:** yes ## How it compares Compared against segment TOPCon 700-750 W (420 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 740 W | 715 W | Strong - top 2% | | | Module efficiency | 23.80% | 23.00% | Strong - top 3% | 433 | | Power density | 238.2 | 230.2 | Strong - top 2% | 431 | | Temperature coefficient | -0.280 | -0.290 | Strong - top 11% | 1,309 | | Weight (kg) | 37.3 kg | 38.0 kg | Strong - top 19% | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 23.80% | 23.00% | Strong - top 3% | 433 | | Power density | 238.2 | 230.2 | Strong - top 2% | 431 | | Temperature coefficient | -0.280 | -0.290 | Strong - top 11% | 1,309 | | Weight per kWp | 50.4 | 52.9 | Strong - top 19% | 3,784 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Strengths - **238.2 watts per square metre** - Top 2% of the TOPCon 700-750 W segment, against a median of 230.2. Ranked 431st in the whole database. - **23.80% module efficiency** - Top 3% of the TOPCon 700-750 W segment, against a median of 23.00%. Ranked 433rd in the whole database. - **-0.280 %/°C temperature coefficient** - Top 11% of the TOPCon 700-750 W segment, against a median of -0.290. - **Best for:** Utility-scale, commercial and shaded-installations. ## Specification ### Electrical - **Rated power (Pmax):** 740 W - **Efficiency:** 23.80 % - **Voltage at Pmax (Vmp):** 41.69 V - **Current at Pmax (Imp):** 17.75 A - **Open-circuit voltage (Voc):** 49.80 V - **Short-circuit current (Isc):** 18.81 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 ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** TOPCon - **Cell count:** 132 - **Bifacial:** yes - **Bifacial gain:** 25.00 ### Physical - **Length:** 2384 mm - **Width:** 1303 mm - **Thickness:** 33 mm - **Weight:** 37.3 kg - **Area:** 3.11 m2 - **Power density:** 238.2 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:** 647 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 433 of 14005 | | Power density | 431 of 14005 | | Temperature coefficient | 1309 of 14005 | | Weight | 3784 of 14005 | | Warranty | 21 of 14005 | ## About this series The TNC 2.0 TWMNF-66HD series from Tongwei is a next-generation line of photovoltaic modules built around **N-type TOPCon cells**, combining strong operational stability with limited long-term power degradation. The use of **half-cut cell technology** along with a dense busbar layout helps reduce resistive losses and improve heat dissipation, resulting in more stable energy output even under partial shading conditions. The **bifacial design** allows the module to capture additional energy from its rear side, making it especially valuable for installations on reflective ground surfaces or in ground-mounted and tracker-based systems. The TWMNF-66HD series is engineered for large commercial and industrial installations, where what matters is not only unit performance but also a **low levelized cost of energy (LCOE)** and straightforward integration with BoS components. Thanks to a reinforced frame and robust mechanical construction, the modules perform well under demanding climate conditions, including high snow and wind loads. This is a solution for investors and installers looking for efficient, predictable module performance over the long term, while staying competitively priced within the N-type module segment. ## Notable figures - At 23.8% efficiency, this panel is 0.8pp above typical \*\*TOPCon 700-750W\*\* modules (median: 23.0%) - 238.2 W/m² power density - 8.0 W/m² more than \*\*TOPCon 700-750W\*\* median (230.2 W/m²), more power per roof area - At -0.28%/°C, hot weather performance is typical for \*\*TOPCon 700-750W\*\* panels - Bifaciality factor of 80% can add 4-12% extra yield with reflective mounting surface - In the top 3% for efficiency among all TOPCon panels ## Questions ### How do the N-type TOPCon cells in the TNC 2.0 TWMNF-66HD series differ from older PERC cells? N-type TOPCon cells used in the TWMNF-66HD show lower power degradation over time and better performance at high temperatures than traditional PERC cells. The panels reach an efficiency of 23.5-24.1%, with a temperature coefficient of Pmax of only -0.28%/°C, meaning smaller output losses on hot days. This translates into higher energy yield over the module's 30-year service life. ### What is the maximum power output of the Tongwei TWMNF-66HD panels and how many cells do they contain? The TNC 2.0 TWMNF-66HD series delivers up to 750 Wp, with variants ranging from 730 to 750 Wp. The module is built with 132 half-cut cells, which reduces resistive losses and improves shading tolerance compared to panels with full-size cells. High unit power lowers the number of modules needed for large commercial installations. ### How much extra energy does the bifacial design of the TWMNF-66HD panels generate? The dual-sided, bifacial construction lets the module capture additional energy reflected off the ground on its rear side. The actual gain depends on the albedo of the surface below the array, mounting height, and tilt angle, but with a bright ground surface such as gravel it can add anywhere from a few to over ten percent more annual energy compared to a monofacial module. The effect is most pronounced in ground-mount and tracker installations. ### What warranty comes with the Tongwei TNC 2.0 TWMNF-66HD panels? The manufacturer offers a 12-year product warranty along with a 30-year linear power warranty, guaranteeing 99% output after the first year and 87.4% after 30 years. This is standard for modern N-type modules and gives investors predictable long-term economics for their solar installation. ### Are the TWMNF-66HD panels suitable for large commercial and industrial roofs? Yes, the module measures 2384x1303x33 mm and weighs about 37.3 kg, which is typical for large C&I and utility-scale panels. A reinforced frame provides resistance to heavy snow and wind loads, and the high unit power of 750 Wp reduces the number of modules, cabling, and mounting hardware needed, lowering BoS costs for large rooftop and ground-mount installations. ### Is Tongwei a reliable, established solar panel manufacturer? Tongwei is a Tier 1 manufacturer based in China and one of the world's largest suppliers of solar cells and modules, present in the supply chain of many global commercial and utility-scale projects. Tier 1 status reflects financial stability and a long track record, which matters when enforcing the 30-year power warranty and securing bank financing for large PV projects. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/ba7a38814c1e25658062446f.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | -40 W, lighter, +1.2 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | -45 W, lighter, +1.1 pp | | [AIKO AIKO-A690-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a690-mae78dw) | 690 W | -50 W, lighter, +0.9 pp | | [AIKO AIKO-A790-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a790-grh78dw) | 790 W | +50 W, heavier, +0.8 pp | | [Trina Solar TSM-NEG21C.20Q-760](https://comparepv.com/panel/trina-solar-tsm-neg21c-20q-760) | 760 W | +20 W, cooler, +0.7 pp | | [AIKO AIKO-A785-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a785-grh78dw) | 785 W | +45 W, heavier, +0.6 pp | | [Gokin GK-4-78HGBD-780M](https://comparepv.com/panel/gokin-gk-4-78hgbd-780m) | 780 W | +40 W, cooler, +0.5 pp | | [AIKO AIKO-A780-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a780-grh78dw) | 780 W | +40 W, heavier, +0.5 pp | | [Jetion JT755SLk(B)](https://comparepv.com/panel/jetion-jt755slk-b) | 755 W | +15 W, cooler, +0.5 pp | | [Trina Solar TSM-NEG21C.20Q-755](https://comparepv.com/panel/trina-solar-tsm-neg21c-20q-755) | 755 W | +15 W, cooler, +0.5 pp | | [Tongwei TWMPF-66HD655](https://comparepv.com/panel/tw-solar-tongwei-twmpf-66hd655) | 655 W | -85 W, hotter, -2.7 pp | | [Tongwei TWMPF-66HD660](https://comparepv.com/panel/tw-solar-tongwei-twmpf-66hd660) | 660 W | -80 W, hotter, -2.6 pp | | [Tongwei TWMPF-66HD665](https://comparepv.com/panel/tw-solar-tongwei-twmpf-66hd665) | 665 W | -75 W, hotter, -2.4 pp | | [Tongwei TWMPF-66HD670](https://comparepv.com/panel/tw-solar-tongwei-twmpf-66hd670) | 670 W | -70 W, hotter, -2.2 pp | | [Tongwei TWMPF-66HD675](https://comparepv.com/panel/tw-solar-tongwei-twmpf-66hd675) | 675 W | -65 W, hotter, -2.1 pp | | [Tongwei TWMNF-66HD700XX](https://comparepv.com/panel/tw-solar-tongwei-twmnf-66hd700xx) | 700 W | -40 W, -1.3 pp | | [AIKO AIKO-A805-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a805-grh78dw) | 805 W | +65 W, heavier, +1.3 pp | --- Source: https://comparepv.com/panel/tongwei-solar-twmnf-66hd740 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.