--- title: "Talesun TD8G66M/665W 665W Solar Panel - Specs & Review | ComparePV" description: "Talesun TD8G66M/665W 665W solar panel. Specs: 21.40% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/talesun-td8g66m-665w" updated: 2026-09-11 --- # Talesun TD8G66M/665W Middle of its segment, heavy for its output 320 panels in the segment PERC 650-700 W ## Identity - **Manufacturer:** Talesun - **Model:** TD8G66M/665W - **Series:** TD8G66M (BIPRO) - **Rated power:** 665 W - **Cell technology:** PERC - **Bifacial:** yes ## How it compares Compared against segment PERC 650-700 W (320 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 665 W | 660 W | Typical | | | Module efficiency | 21.40% | 21.25% | Typical | 8,323 | | Power density | 214.1 | 212.5 | Typical | 8,250 | | Temperature coefficient | -0.340 | -0.340 | Typical | 8,778 | | Weight (kg) | 38.5 kg | 34.5 kg | Weak - bottom 24% | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 21.40% | 21.25% | Typical | 8,323 | | Power density | 214.1 | 212.5 | Typical | 8,250 | | Temperature coefficient | -0.340 | -0.340 | Typical | 8,778 | | Weight per kWp | 57.9 | 52.3 | Weak - bottom 24% | 11,470 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Watch out for - **57.9 kg per kWp** - Bottom 24% of the PERC 650-700 W segment, against a median of 52.3. - **Best for:** Commercial, utility-scale and shaded-installations. - **Not ideal for:** Weight-limited structures. ## Specification ### Electrical - **Rated power (Pmax):** 665 W - **Efficiency:** 21.40 % - **Voltage at Pmax (Vmp):** 38.40 V - **Current at Pmax (Imp):** 17.32 A - **Open-circuit voltage (Voc):** 46.00 V - **Short-circuit current (Isc):** 18.41 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.340 %/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:** PERC - **Cell count:** 132 - **Bifacial:** yes ### Physical - **Length:** 2384 mm - **Width:** 1303 mm - **Thickness:** 35 mm - **Weight:** 38.5 kg - **Area:** 3.11 m2 - **Power density:** 214.1 Wp/m2 ### Warranty and degradation - **Product warranty:** 12 years - **Performance warranty:** 30 years - **Output guaranteed at end of warranty:** 85.0 % - **First-year degradation:** 2.00 % - **Annual degradation:** 0.45 % - **Output after 30 years:** 565 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 8323 of 14005 | | Power density | 8250 of 14005 | | Temperature coefficient | 8778 of 14005 | | Weight | 11470 of 14005 | | Warranty | 21 of 14005 | ## About this series The Talesun TD8G66M (BIPRO) series are dual-glass modules featuring a **dual glass** configuration, meticulously designed to genuinely increase energy yield in locations where every additional kilowatt-hour counts. The application of **bifacial PERC technology** harnesses light reflecting off the ground, proving especially effective on light-colored roofs, ground-mounted structures, carports, and industrial installations. A key feature of this series is the **12BB and half-cut technology**, involving denser connection ribbons and divided cells - a solution supporting more stable performance under partial shading and minimizing connection losses. The manufacturer also highlights **high PID resistance** and a design optimized for challenging conditions - moisture, dust, and wind - making these modules well-suited for PV farms and facilities demanding enhanced durability. This is an offering for investors seeking to combine greater energy yield with a robust, glass-glass construction. ## Notable figures - At 21.4% efficiency, this panel is on par with typical \*\*PERC 650-700W\*\* modules - Power density of 214.1 W/m² matches the \*\*PERC 650-700W\*\* median - Temperature coefficient of -0.34%/°C matches the \*\*PERC 650-700W\*\* median - Weight of 38.5 kg is 4.0 kg above \*\*PERC 650-700W\*\* median (34.5 kg) - verify structural support - Bifaciality factor of 70% can add 4-10% extra yield with reflective mounting surface ## Questions ### What is the maximum power output of the Talesun TD8G66M (BIPRO) panel? The TD8G66M series reaches up to 670 Wp thanks to 132 half-cut PERC cells arranged with a 12BB busbar grid. This design reduces current losses and delivers higher module efficiency compared to classic full-cell panels, while maintaining comparable dimensions. ### How does the bifacial TD8G66M panel differ from a standard monofacial panel? Thanks to its dual glass construction and bifacial PERC technology, the TD8G66M generates additional energy from its rear side by capturing light reflected off the ground. In practice, this means extra yield when installed on light-colored roofs, ground-mount structures, carports, or PV farms, where surrounding reflectance is higher than on dark ground. ### What warranty comes with the Talesun TD8G66M (BIPRO) panels? The manufacturer provides a 12-year product warranty and a 30-year linear power output warranty. This is typical for higher-tier glass-glass modules, reflecting their greater resistance to degradation and mechanical damage compared to standard backsheet panels. ### Is the Talesun TD8G66M (BIPRO) series still available for purchase? No, production of the TD8G66M (BIPRO) series has been discontinued by the manufacturer. Limited stock may still be available through distributors while supplies last, but it is no longer offered as a current model in Talesun's lineup. Check availability with your supplier before planning a large installation based solely on this model. ### Are TD8G66M panels suitable for industrial and utility-scale PV farms? Yes, the glass-glass construction with high PID resistance and durability against moisture, dust, and wind make the TD8G66M series well suited to large ground-mount installations and PV farms. The bifacial technology further improves economics in such projects, since ground-mount structures allow full use of the rear-side energy potential. ### Who manufactures Talesun panels and is it a Tier 1 supplier? Talesun is a Chinese solar module manufacturer classified as a Tier 1 supplier, indicating stable financial standing and bankability recognized by project financiers. Tier 1 status matters when securing financing or subsidies for a PV installation, as many lenders require panels from recognized manufacturers. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/158515293863030f638f465-b9c5be2b22c4.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A650-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a650-mae72mw) | 650 W | Cooler, lighter, +3.8 pp | | [AIKO AIKO-A680-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a680-mde72mw) | 680 W | Cooler, lighter, +3.8 pp | | [AIKO AIKO-A675-MDE72Mw](https://comparepv.com/panel/aiko-aiko-a675-mde72mw) | 675 W | Cooler, lighter, +3.6 pp | | [AIKO AIKO-A645-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a645-mae72mw) | 645 W | Cooler, lighter, +3.6 pp | | [AIKO AIKO-A700-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a700-mae78dw) | 700 W | Cooler, lighter, +3.6 pp | | [AIKO AIKO-A695-MAE78Dw](https://comparepv.com/panel/aiko-aiko-a695-mae78dw) | 695 W | Cooler, lighter, +3.5 pp | | [AIKO AIKO-G670-MCH72Mw](https://comparepv.com/panel/aiko-aiko-g670-mch72mw) | 670 W | Cooler, lighter, +3.4 pp | | [Talesun TP8F66M-650](https://comparepv.com/panel/talesun-tp8f66m-650) | 650 W | Lighter, -0.5 pp, -5 yr warranty | | [Talesun TP8F66M-655](https://comparepv.com/panel/talesun-tp8f66m-655) | 655 W | Lighter, -0.3 pp, -5 yr warranty | | [Talesun TP8F66M-660](https://comparepv.com/panel/talesun-tp8f66m-660) | 660 W | Lighter, -5 yr warranty | | [Talesun TD8G66M/670W](https://comparepv.com/panel/talesun-td8g66m-670w) | 670 W | +0.2 pp | | [AIKO AIKO-A805-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a805-grh78dw) | 805 W | +140 W, cooler, +3.7 pp | | [AIKO AIKO-A800-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a800-grh78dw) | 800 W | +135 W, cooler, +3.5 pp | | [AIKO AIKO-A795-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a795-grh78dw) | 795 W | +130 W, cooler, +3.4 pp | | [AIKO AIKO-A790-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a790-grh78dw) | 790 W | +125 W, cooler, +3.2 pp | | [Trina Solar TSM-NEG21C.20Q-760](https://comparepv.com/panel/trina-solar-tsm-neg21c-20q-760) | 760 W | +95 W, cooler, +3.1 pp | --- Source: https://comparepv.com/panel/talesun-td8g66m-665w Not in this file, on the page: a thirty-year output simulator, a bifacial gain calculator and alternatives filtered by how closely they match these dimensions.