--- title: "Tongwei THC G12-66 Bifacial 740W Solar Panel - Specs & Review | ComparePV" description: "Tongwei THC G12-66 Bifacial 740W solar panel. Specs: 23.80% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/tongwei-thc-g12-66-bifacial" updated: 2026-09-11 --- # Tongwei THC G12-66 Bifacial Space saver, no clear weak spot 420 panels in the segment TOPCon 700-750 W ## Identity - **Manufacturer:** Tongwei - **Model:** THC G12-66 Bifacial - **Series:** TNC and THC Series - **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) | 37.0 kg | 38.0 kg | Strong - top 17% | | | 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 | 50.0 | 52.9 | Strong - top 17% | 3,317 | | 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:** Commercial, utility-scale and hot-climate. ## Specification ### Electrical - **Rated power (Pmax):** 740 W - **Efficiency:** 23.80 % - **Voltage at Pmax (Vmp):** 42.32 V - **Current at Pmax (Imp):** 17.49 A - **Open-circuit voltage (Voc):** 50.62 V - **Short-circuit current (Isc):** 18.47 A ### Temperature - **Temperature coefficient of Pmax:** -0.280 %/degC - **Temperature coefficient of Voc:** -0.220 %/degC - **Temperature coefficient of Isc:** 0.040 %/degC - **NOCT:** 45 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** TOPCon - **Cell count:** 132 - **Bifacial:** yes ### Physical - **Length:** 2384 mm - **Width:** 1303 mm - **Thickness:** 33 mm - **Weight:** 37.0 kg - **Area:** 3.11 m2 - **Power density:** 238.2 Wp/m2 ### Warranty and degradation - **Product warranty:** 15 years - **Performance warranty:** 30 years ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 433 of 14005 | | Power density | 431 of 14005 | | Temperature coefficient | 1309 of 14005 | | Weight | 3317 of 14005 | | Warranty | 21 of 14005 | ## About this series The Tongwei TNC and THC panel series is a technological breakthrough based on N-type cells that redefines efficiency standards in modern photovoltaics. The use of advanced **TOPCon and HJT** structures allows for achieving parameters unavailable to older technologies, which directly translates to a greater amount of energy harvested from the same roof area. TNC models stand out with **minimal annual degradation**, providing investors with long-term security and financial stability throughout the entire service life. In turn, the THC line, based on heterojunction technology, offers an **excellent temperature coefficient**, thanks to which the modules operate extremely efficiently even during extreme summer heat. These products effectively solve the problem of limited installation space, delivering more power from every square meter of the installation. The manufacturer's unique vertical integration guarantees the highest quality of silicon, which distinguishes these series from the competition in terms of durability and purity of components. The TNC and THC series is the optimal choice for business and residential projects where the priority is **maximizing energy yields** while reducing operating costs. This is a solution for those looking for future technology ready to work in the demanding Polish climate. ## Notable figures - 23.8% module efficiency - 0.8pp better than the \*\*TOPCon 700-750W\*\* median of 23.0% - Power density of 238.2 W/m² packs 8.0 W/m² more into the same footprint vs \*\*TOPCon 700-750W\*\* median (230.2 W/m²) - Temperature coefficient of -0.28%/°C matches the \*\*TOPCon 700-750W\*\* median - At 37.0 kg, weight matches the \*\*TOPCon 700-750W\*\* median - Bifacial design (85% factor) captures reflected light - adds 4-13% yield on ground-mount or white roof ## Questions ### What is the difference between Tongwei's TNC and THC panel series? The TNC series uses N-type TOPCon cells, delivering high efficiency and minimal annual degradation, ideal for projects focused on stable, long-term energy yield. The THC series is based on heterojunction (HJT) technology, offering a better temperature coefficient so modules lose less power during hot weather. The choice depends on installation climate and investment priorities. ### What is the maximum power output of Tongwei TNC and THC panels? The most powerful variants in both series reach up to 740 Wp, placing them among the top-tier bifacial N-type modules currently available. Higher wattage per panel reduces the number of modules needed to reach a target system size, lowering mounting structure and installation labor costs. ### Are Tongwei TNC/THC panels bifacial, and is it worth it? Yes, both series feature bifacial construction, allowing panels to generate additional energy from light reflected off the ground or roof surface. This typically boosts overall energy yield, especially with bright surfaces or elevated ground-mount installations. The bifacial gain is less pronounced on standard dark-roof residential installations. ### What warranty comes with Tongwei TNC and THC series panels? The manufacturer offers a 15-year product warranty and a 30-year linear power warranty, among the longest currently available in the PV market. This warranty structure gives investors confidence in long-term durability and predictable energy output over the entire lifespan of the installation. ### Is Tongwei a reliable, established solar panel manufacturer? Tongwei is a Tier 1 manufacturer headquartered in China with full vertical integration, from polysilicon production through to finished modules. This supply chain control ensures consistent, high-quality silicon and stable production output, which matters for larger commercial and industrial-scale projects. ### Do Tongwei TOPCon panels perform well in hot summer conditions? Yes, the TOPCon and HJT cells used in the TNC and THC series have a favorable temperature coefficient, limiting power loss at high module operating temperatures compared to older technologies like PERC. This matters especially in summer, when rooftop panel temperatures can significantly exceed ambient air temperature. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/Tongwei_TW_Solar-TWMHF-66HD-715-740W_THC_datasheet.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-thc-g12-66-bifacial 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.