--- title: "G-STAR GSD8K66T-720WT 720W Solar Panel - Specs & Review | ComparePV" description: "G-STAR GSD8K66T-720WT 720W solar panel. Specs: 23.18% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/g-star-gsd8k66t-720wt" updated: 2026-09-11 --- # G-STAR GSD8K66T-720WT Middle of its segment, weak in heat 420 panels in the segment TOPCon 700-750 W ## Identity - **Manufacturer:** G-STAR - **Model:** GSD8K66T-720WT - **Series:** GSD8K66T - **Rated power:** 720 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) | 720 W | 715 W | Typical | | | Module efficiency | 23.18% | 23.00% | Typical | 1,424 | | Power density | 231.8 | 230.2 | Typical | 1,347 | | Temperature coefficient | -0.300 | -0.290 | Weak - bottom 22% | 6,093 | | Weight (kg) | 38.0 kg | 38.0 kg | Typical | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 23.18% | 23.00% | Typical | 1,424 | | Power density | 231.8 | 230.2 | Typical | 1,347 | | Temperature coefficient | -0.300 | -0.290 | Weak - bottom 22% | 6,093 | | Weight per kWp | 52.8 | 52.9 | Typical | 6,459 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Watch out for - **-0.300 %/°C temperature coefficient** - Bottom 22% of the TOPCon 700-750 W segment, against a median of -0.290. - **Best for:** Utility-scale, commercial and shaded-installations. - **Not ideal for:** Hot climates. ## Specification ### Electrical - **Rated power (Pmax):** 720 W - **Efficiency:** 23.18 % - **Voltage at Pmax (Vmp):** 40.91 V - **Current at Pmax (Imp):** 17.60 A - **Open-circuit voltage (Voc):** 49.36 V - **Short-circuit current (Isc):** 18.26 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.300 %/degC - **Temperature coefficient of Voc:** -0.250 %/degC - **Temperature coefficient of Isc:** 0.046 %/degC - **NOCT:** 43 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:** 38.0 kg - **Area:** 3.11 m2 - **Power density:** 231.8 Wp/m2 ### Warranty and degradation - **Product warranty:** 15 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:** 629 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 1424 of 14005 | | Power density | 1347 of 14005 | | Temperature coefficient | 6093 of 14005 | | Weight | 6459 of 14005 | | Warranty | 21 of 14005 | ## Pros - **Efficiency on par with segment leaders** - Efficiency up to 23.34% matches or exceeds top comparable series (Trina Solar Vertex N i-TOPCon and TCL Zhonghuan G12-66P – both 23.3%), placing the GSD8K66T among the leading N-type modules currently on the market. - **N-type TOPCon technology with SMBB** - The combination of half-cut monocrystalline TOPCon cells with multi-busbar (SMBB) technology improves light capture and reduces resistive losses versus older PERC designs, resulting in higher and more stable energy yield. - **Bifacial dual-glass construction** - The bifacial design with tempered dual glass captures ground-reflected radiation, boosting rear-side energy yield by roughly 10–25%, which is particularly valuable for ground-mount installations on bright, reflective surfaces. - **30-year linear power warranty** - The manufacturer offers a 30-year linear power warranty alongside a 15-year product warranty, matching the premium standard among N-type TOPCon modules and the terms offered by leading players in the segment. - **High unit power up to 725 Wp** - The 700–725 Wp power range matches the highest values achieved by comparable series from TCL Zhonghuan G12-66P and Trina Vertex N, reducing the number of modules needed per MWp and lowering BoS costs in large-scale installations. ## Cons - **Manufacturer not on the Tier-1 (BNEF) list** - G-STAR does not appear on Bloomberg NEF's Tier-1 bankable manufacturer list, unlike the comparable series from Trina Solar and TCL Zhonghuan, both recognized Tier-1 suppliers. This may complicate securing bank financing for large commercial and industrial projects. ## About this series The GSD8K66T series comprises bifacial N-Type photovoltaic modules built on **TOPCon** technology, combining half-cut monocrystalline cells with a dual tempered glass construction. Thanks to **SMBB (multi-busbar) technology**, the panels achieve better light trapping and more efficient current collection, delivering higher efficiency and more stable performance than conventional designs. The **bifacial** design also captures light reflected from the ground, boosting rear-side energy yield by up to several tens of percent, making this series particularly attractive for ground-mounted installations and sites with highly reflective surfaces. The dual-glass construction and anodized aluminum frame provide strong **resistance to moisture, wind, and dust**, allowing the modules to perform reliably in harsh climates and demanding industrial environments. An optimized manufacturing process ensures excellent **resistance to PID degradation and LID/LETID effects**, translating into a longer service life and lower annual power loss over the module's operating lifetime. The GSD8K66T series is designed for commercial and industrial investors seeking a low LCOE across the full lifetime of their solar installation. ## Notable figures - At 23.2% efficiency, this panel is on par with typical \*\*TOPCon 700-750W\*\* modules - Power density of 231.8 W/m² matches the \*\*TOPCon 700-750W\*\* median - At -0.30%/°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 10% for efficiency among all TOPCon panels ## Questions ### How does the GSD8K66T series differ from standard monocrystalline panels? The GSD8K66T series uses N-Type TOPCon half-cut cells with SMBB technology, meaning more busbars than traditional panels. This improves current collection and reduces energy losses. It's also bifacial, generating power from the rear side as well, unlike conventional single-sided modules. ### How much extra energy does the bifacial design of the GSD8K66T actually deliver? Depending on the ground surface, mounting height, and light reflectivity, the rear side can add roughly ten to over twenty percent additional energy on top of the front-side rated power. The highest gains occur on bright, reflective surfaces such as gravel, white roofing, or snow, making this series especially well-suited for ground-mounted installations. ### What warranty comes with the GSD8K66T panels? Manufacturer G-STAR provides a 15-year product warranty and a 30-year power (performance) warranty. This means the module is covered against material and workmanship defects for the full period, and its power output won't drop below the guaranteed level specified in the datasheet. ### Are GSD8K66T panels resistant to PID and LID degradation? Yes, the GSD8K66T series is optimized for resistance to PID degradation as well as LID and LETID effects, which in lower-quality modules cause faster power loss in the first years of operation. This results in lower annual degradation and more stable performance throughout the module's lifespan. ### What type of installations is the GSD8K66T series best suited for? With a maximum power output of up to 725 Wp, bifacial design, and a robust anodized aluminum frame, the GSD8K66T series targets commercial and industrial projects, including ground-mounted solar farms. The high per-module power reduces the number of panels needed to reach a target system capacity, lowering installation and cabling costs. ### Can GSD8K66T panels handle harsh climate conditions? Yes, the dual tempered glass and anodized aluminum frame provide resistance to moisture, strong wind, and dust. This construction is built for demanding environments, including industrial sites and areas with variable climate conditions, making it suitable for long-term commercial installations. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/1773718375588064-04a20d694460.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | -40 W, lighter, +2.0 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | -45 W, lighter, +1.8 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | Cooler, lighter, +1.8 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | Cooler, lighter, +1.7 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | -50 W, lighter, +1.6 pp | | [Longi Solar LR7-72HVHF-670M](https://comparepv.com/panel/longi-lr7-72hvhf-670m) | 670 W | -50 W, lighter, +1.6 pp | | [Jinko Solar JKM650-670N-66QL6-BDV (670W class)](https://comparepv.com/panel/jinko-solar-jkm650-670n-66ql6-bdv-670w-class) | 670 W | -50 W, lighter, +1.6 pp | | [G-STAR GSD8K66T-700WT](https://comparepv.com/panel/g-star-gsd8k66t-700wt) | 700 W | -20 W, -0.6 pp | | [G-STAR GSD8K66T-705WT](https://comparepv.com/panel/g-star-gsd8k66t-705wt) | 705 W | -15 W, -0.5 pp | | [G-STAR GSD8K66T-710WT](https://comparepv.com/panel/g-star-gsd8k66t-710wt) | 710 W | -10 W, -0.3 pp | | [G-STAR GSD8K66T-715WT](https://comparepv.com/panel/g-star-gsd8k66t-715wt) | 715 W | Very close match | | [G-STAR GSD8K66T-725WT](https://comparepv.com/panel/g-star-gsd8k66t-725wt) | 725 W | Very close match | | [AIKO AIKO-A805-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a805-grh78dw) | 805 W | +85 W, cooler, +1.9 pp | | [AIKO AIKO-A800-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a800-grh78dw) | 800 W | +80 W, cooler, +1.7 pp | | [AIKO AIKO-A795-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a795-grh78dw) | 795 W | +75 W, cooler, +1.6 pp | | [AIKO AIKO-A790-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a790-grh78dw) | 790 W | +70 W, cooler, +1.4 pp | --- Source: https://comparepv.com/panel/g-star-gsd8k66t-720wt 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.