--- title: "G-STAR GSD8R66T-610WT 610W Solar Panel - Specs & Review | ComparePV" description: "G-STAR GSD8R66T-610WT 610W solar panel. Specs: 22.58% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/g-star-gsd8r66t-610wt" updated: 2026-09-11 --- # G-STAR GSD8R66T-610WT Middle of its segment, weak in heat 1,086 panels in the segment TOPCon 600-650 W ## Identity - **Manufacturer:** G-STAR - **Model:** GSD8R66T-610WT - **Series:** GSD8R66T - **Rated power:** 610 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) | 610 W | 620 W | Typical | | | Module efficiency | 22.58% | 22.80% | Typical | 3,828 | | Power density | 225.8 | 227.7 | Typical | 3,729 | | Temperature coefficient | -0.300 | -0.290 | Weak - bottom 19% | 6,093 | | Weight (kg) | 33.0 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 | 22.58% | 22.80% | Typical | 3,828 | | Power density | 225.8 | 227.7 | Typical | 3,729 | | Temperature coefficient | -0.300 | -0.290 | Weak - bottom 19% | 6,093 | | Weight per kWp | 54.1 | 53.1 | Typical | 8,325 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Watch out for - **-0.300 %/°C temperature coefficient** - Bottom 19% of the TOPCon 600-650 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):** 610 W - **Efficiency:** 22.58 % - **Voltage at Pmax (Vmp):** 40.73 V - **Current at Pmax (Imp):** 14.98 A - **Open-circuit voltage (Voc):** 48.54 V - **Short-circuit current (Isc):** 15.75 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:** 2382 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 33.0 kg - **Area:** 2.70 m2 - **Power density:** 225.8 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:** 533 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 3828 of 14005 | | Power density | 3729 of 14005 | | Temperature coefficient | 6093 of 14005 | | Weight | 8325 of 14005 | | Warranty | 21 of 14005 | ## Pros - **Best-in-class segment efficiency** - Maximum efficiency of 23.51% matches the top performers among peer comparables in the 635W class - Sunpro Power TOPCon 210R BIFACIAL (23.51%) and exceeds Longi Hi-MO X10 (23.5%) and Talesun TM7G78M (22.72%). This places the series at the leading edge of available TOPCon bifacial modules at comparable power ratings. - **30-year linear power warranty** - The 30-year power warranty exceeds the standard 25 years offered by many Tier-1 manufacturers, and combined with N-type TOPCon technology translates into a lower annual degradation rate and more stable energy yield over the long investment horizon. - **Bifacial dual-side energy generation** - The dual glass construction with bifacial cells enables additional energy capture from albedo reflected off the ground, particularly advantageous in ground-mount installations and bright rooftop surfaces, lowering the effective LCOE. - **1500V system compatibility** - Support for 1500V system voltage allows longer strings and fewer BoS components (cabling, inverters, protection devices), reducing installation costs for both rooftop and utility-scale PV projects. - **Rectangular half-cut cell layout** - The use of half-cut cells reduces resistive losses and improves partial shading tolerance compared to conventional full-size cells, resulting in more stable output under variable irradiance conditions. ## Cons - **Manufacturer not on BNEF Tier-1 list** - G-STAR does not appear on the BloombergNEF Tier-1 list, meaning no confirmed track record of supplying at least six projects above 10 MW financed by independent commercial banks. This can complicate bank financing for large-scale farm projects compared to series from Longi or Talesun. - **Limited market track record** - Launched in 2023, the series has a relatively short field-operating history compared to established brands in the peer comparables set, raising questions about the manufacturer's capacity to honor the 30-year power warranty over such a long horizon. ## About this series The G-STAR GSD8R66T series consists of solar modules engineered to capture every ray of sunlight by combining **TOPCon** cell technology with a dual-sided **bifacial** design. The use of **half-cut cells** arranged in a rectangular layout reduces resistive losses and minimizes the impact of partial shading, resulting in more stable energy output throughout the day. The **dual glass** construction provides high mechanical resistance and long-term durability, limiting performance degradation even under harsh conditions such as moisture, snow load, or intense sunlight. With support for a **1500V system voltage**, these panels are well suited for both rooftop installations and large-scale solar farms, where optimizing BoS costs and lowering the LCOE of energy production matter most. The GSD8R66T series meets the needs of investors seeking a balance between high performance and long-term reliability, while offering an attractive alternative to costlier HJT solutions. It is a solid choice for installers and PV project developers who value proven technology, supply chain stability, and quality-assurance certifications. ## Notable figures - Efficiency of 22.6% matches the \*\*TOPCon 600-650W\*\* median - At 225.8 W/m² power density, roof space requirements are typical for \*\*TOPCon 600-650W\*\* panels - Temperature coefficient of -0.30%/°C matches the \*\*TOPCon 600-650W\*\* median - Bifaciality factor of 80% can add 4-12% extra yield with reflective mounting surface - #3828 for efficiency, #6093 for temperature performance out of 14005 panels ## Questions ### What is the maximum power output of the G-STAR GSD8R66T panel? The GSD8R66T series reaches a maximum power output of up to 635 Wp. This is achieved by combining TOPCon cell technology with a bifacial double-glass design and rectangular half-cut cells that reduce current losses. Higher wattage per module means fewer panels are needed for the same array capacity, lowering mounting and racking costs. ### How does TOPCon technology in the GSD8R66T differ from standard PERC panels? TOPCon is a newer cell technology that uses an additional passivation layer to reduce electron recombination on the back side of the cell. This results in higher efficiency and lower long-term power degradation compared to conventional PERC cells. The GSD8R66T combines TOPCon with a bifacial design, allowing it to generate extra energy from reflected light on the rear side of the module. ### Are GSD8R66T panels suitable for large-scale solar farms and 1500V systems? Yes, the GSD8R66T series supports a 1500V system voltage, which is the standard for utility-scale projects. This allows for longer strings, fewer inverters and less cabling, reducing BoS costs and improving the overall LCOE. As a result, these panels work well both for rooftop installations and large solar farms. ### What warranty comes with G-STAR GSD8R66T panels? The manufacturer provides a 15-year product warranty along with a 30-year linear power output warranty. This means the module retains a guaranteed percentage of its original power output over three decades, which is an important factor when calculating the long-term profitability of an installation. ### How much extra energy do bifacial GSD8R66T panels produce? The bifacial design lets the panel capture reflected light on its rear side in addition to direct sunlight on the front. Depending on the albedo of the mounting surface (such as light-colored gravel or a white roof) and installation height, the additional energy gain can range from a few percent up to more than ten percent compared to monofacial panels of the same rated power. ### Is the GSD8R66T a good alternative to more expensive HJT panels? Yes, the GSD8R66T series was designed as a balance between high performance and purchase cost. TOPCon technology approaches HJT-level efficiency and low degradation but at a lower manufacturing cost. For investors looking for a strong value-for-money ratio without giving up modern cell technology, it is a reasonable alternative. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/1773718473449266-653f40351a57.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | +40 W, lighter, +2.6 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +2.4 pp | | [Longi Solar LR7-60HVH-560M](https://comparepv.com/panel/longi-lr7-60hvh-560m) | 560 W | -50 W, lighter, +2.2 pp | | [AIKO AIKO-A640-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a640-mae72mw) | 640 W | Cooler, lighter, +2.2 pp | | [AIKO AIKO-A635-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a635-mae72mw) | 635 W | Cooler, lighter, +2.0 pp | | [Longi Solar LR8-66HVD-660M](https://comparepv.com/panel/longi-lr8-66hvd-660m) | 660 W | +50 W, cooler, +1.9 pp | | [G-STAR GSD8R66T-615WT](https://comparepv.com/panel/g-star-gsd8r66t-615wt) | 615 W | Very close match | | [G-STAR GSD8R66T-620WT](https://comparepv.com/panel/g-star-gsd8r66t-620wt) | 620 W | +10 W, +0.4 pp | | [G-STAR GSD8R66T-625WT](https://comparepv.com/panel/g-star-gsd8r66t-625wt) | 625 W | +15 W, +0.6 pp | | [G-STAR GSD8R66T-630WT](https://comparepv.com/panel/g-star-gsd8r66t-630wt) | 630 W | +20 W, +0.7 pp | | [G-STAR GSD8R66T-635WT](https://comparepv.com/panel/g-star-gsd8r66t-635wt) | 635 W | +25 W, +0.9 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | +70 W, lighter, +2.6 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | +65 W, lighter, +2.4 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | +90 W, cooler, +2.4 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | +85 W, cooler, +2.3 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | +60 W, lighter, +2.2 pp | --- Source: https://comparepv.com/panel/g-star-gsd8r66t-610wt 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.