--- title: "Tongwei TWMNH-66HD600 600W Solar Panel - Specs & Review | ComparePV" description: "Tongwei TWMNH-66HD600 600W solar panel. Specs: 22.20% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/tongwei-twmnh-66hd600" updated: 2026-09-11 --- # Tongwei TWMNH-66HD600 Strong in heat, modest efficiency 1,086 panels in the segment TOPCon 600-650 W ## Identity - **Manufacturer:** Tongwei - **Model:** TWMNH-66HD600 - **Series:** TWMNH Bifacial Module (66) - **Rated power:** 600 W - **Cell technology:** TOPCon - **Bifacial:** yes ## How it compares Compared against segment TOPCon 600-650 W (1086 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 600 W | 620 W | Weak - bottom 5% | | | Module efficiency | 22.20% | 22.80% | Weak - bottom 12% | 5,817 | | Power density | 222.1 | 227.7 | Weak - bottom 13% | 5,783 | | Temperature coefficient | -0.280 | -0.290 | Strong - top 7% | 1,309 | | Weight (kg) | 32.5 kg | 32.7 kg | Typical | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 22.20% | 22.80% | Weak - bottom 12% | 5,817 | | Power density | 222.1 | 227.7 | Weak - bottom 13% | 5,783 | | Temperature coefficient | -0.280 | -0.290 | Strong - top 7% | 1,309 | | Weight per kWp | 54.2 | 53.1 | Typical | 8,370 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Strengths - **-0.280 %/°C temperature coefficient** - Top 7% of the TOPCon 600-650 W segment, against a median of -0.290. Ranked 1,309th in the whole database. ### Watch out for - **22.20% module efficiency** - Bottom 12% of the TOPCon 600-650 W segment, against a median of 22.80%. - **222.1 watts per square metre** - Bottom 13% of the TOPCon 600-650 W segment, against a median of 227.7. - **Best for:** Utility-scale, commercial and hot-climate. - **Not ideal for:** Tight roof space and roofs where every square metre has to count. ## Specification ### Electrical - **Rated power (Pmax):** 600 W - **Efficiency:** 22.20 % - **Voltage at Pmax (Vmp):** 40.75 V - **Current at Pmax (Imp):** 14.73 A - **Open-circuit voltage (Voc):** 47.50 V - **Short-circuit current (Isc):** 15.75 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:** TOPCon - **Cell count:** 132 - **Bifacial:** yes - **Bifacial gain:** 25.00 ### Physical - **Length:** 2382 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 32.5 kg - **Area:** 2.70 m2 - **Power density:** 222.1 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:** 524 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 5817 of 14005 | | Power density | 5783 of 14005 | | Temperature coefficient | 1309 of 14005 | | Weight | 8370 of 14005 | | Warranty | 21 of 14005 | ## About this series The Tongwei TWMNH Bifacial Module (66) series is based on breakthrough **N-type TOPCon cell** technology, which effectively eliminates the problem of light-induced degradation and ensures higher efficiency in real-world weather conditions. The use of a **bifacial (double-sided)** design allows for effective energy generation not only from direct sunlight but also from rays reflected from the surroundings, which significantly increases the total energy yield of the system. These modules solve the problem of power drops during hot weather thanks to an exceptionally favorable temperature coefficient, which clearly distinguishes them from standard panels. This solution is primarily dedicated to demanding business investors and designers of photovoltaic farms, where **maximizing the yield per unit area** is of key importance. Thanks to the use of advanced multi-busbar technology, the panels are characterized by minimal internal losses and excellent resistance to mechanical loads. By choosing this series, the investor gains **above-average durability and stability of parameters** over a long time horizon, making it one of the most cost-effective options in the high-efficiency segment. It is the optimal choice for modern installations that must meet strict efficiency requirements, guaranteeing **high energy reliability** over many years of use. ## Notable figures - Module efficiency of 22.2% is 0.6pp below average for \*\*TOPCon 600-650W\*\* panels (median: 22.8%) - At 222.1 W/m², this panel generates 5.6 W/m² less per unit area than \*\*TOPCon 600-650W\*\* median (227.7 W/m²) - At -0.28%/°C, hot weather performance is typical for \*\*TOPCon 600-650W\*\* panels - Bifaciality factor of 80% can add 4-12% extra yield with reflective mounting surface - Ranked #5817 out of 14005 panels for efficiency in the database ## Questions ### What is the maximum power output of the Tongwei TWMNH Bifacial Module (66)? Modules from the TWMNH Bifacial (66) series reach a maximum power output of up to 605 Wp. This is achieved through high-efficiency N-type TOPCon cells combined with a bifacial design that further boosts real-world energy yield. This power class places the series in the high-performance segment, appealing for PV farms and large commercial installations where energy output per square meter of roof or ground matters most. ### Is the Tongwei TWMNH Bifacial Module (66) series still available for purchase? No, production of the TWMNH Bifacial Module (66) series has ended and the model has been discontinued from the manufacturer's current lineup. Panels may still be found through distributors as remaining stock, but buyers should verify the production date and warranty validity, or consider newer Tongwei models with comparable or improved specifications as an alternative. ### How does N-TOPCon technology in the Tongwei TWMNH modules differ from standard PERC panels? N-TOPCon cells use an N-type silicon wafer, unlike the P-type substrate common in PERC cells, making them significantly less susceptible to light-induced degradation (LID) and light- and elevated-temperature-induced degradation (LeTID). As a result, TWMNH modules maintain higher efficiency throughout their service life, and their improved temperature coefficient means smaller power losses on hot days. ### What warranty comes with the Tongwei TWMNH Bifacial Module (66)? The manufacturer provides a 12-year product warranty covering material and workmanship defects, along with a 30-year power output warranty guaranteeing the module maintains its rated performance over the long term. This is a standard benchmark for high-end TOPCon panels and an important factor when calculating the return on investment over decades of system operation. ### Are Tongwei TWMNH bifacial panels suitable for large ground-mounted solar farms? Yes, the bifacial design of this series performs especially well in ground-mounted installations, where the rear side of the module can capture additional energy from light reflected off the ground, such as light-colored gravel or grass. Combined with power output up to 605 Wp, TWMNH modules help maximize energy yield per unit of surface area, a key consideration for commercial solar farm investors. ### Is Tongwei a Tier 1 manufacturer, and what does that mean for buyers of TWMNH panels? Yes, Tongwei holds Tier 1 manufacturer status, reflecting strong financial stability, high production capacity, and proven reliability as tracked by independent industry analyses such as Bloomberg NEF. For buyers, this translates into lower risk when it comes to honoring warranty claims down the line and confidence in the manufacturing process quality, even though the TWMNH (66) series itself has since been discontinued. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/188eb01bb2e9207eafc7f25fbf0d61d9-a1b7ca038ac3.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | +50 W, lighter, +3.0 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | +45 W, lighter, +2.8 pp | | [Longi Solar LR7-60HVH-560M](https://comparepv.com/panel/longi-lr7-60hvh-560m) | 560 W | -40 W, lighter, +2.6 pp | | [AIKO AIKO-A640-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a640-mae72mw) | 640 W | +40 W, lighter, +2.6 pp | | [Longi Solar LR7-60HVH-555M](https://comparepv.com/panel/longi-lr7-60hvh-555m) | 555 W | -45 W, lighter, +2.4 pp | | [AIKO AIKO-A635-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a635-mae72mw) | 635 W | +35 W, lighter, +2.4 pp | | [Tongwei TWMNH-48HC](https://comparepv.com/panel/tongwei-twmnh-48hc) | 450 W | -150 W, lighter, -5.5 pp | | [Tongwei TWMNH-54HD](https://comparepv.com/panel/tongwei-twmnh-54hd) | 515 W | -85 W, lighter, -3.1 pp | | [Tongwei TWMNH-66HD605](https://comparepv.com/panel/tongwei-twmnh-66hd605) | 605 W | Very close match | | [Tongwei TWMNH-66HD610](https://comparepv.com/panel/tongwei-solar-twmnh-66hd610) | 610 W | +10 W, +0.4 pp | | [Tongwei TWMNH-66HD615](https://comparepv.com/panel/tongwei-solar-twmnh-66hd615) | 615 W | +15 W, +0.6 pp | | [Tongwei TWMNH-66HD620](https://comparepv.com/panel/tongwei-solar-twmnh-66hd620) | 620 W | +20 W, +0.8 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +80 W, lighter, +3.0 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +75 W, lighter, +2.8 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +100 W, cooler, +2.8 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +95 W, cooler, +2.7 pp | --- Source: https://comparepv.com/panel/tongwei-twmnh-66hd600 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.