--- title: "Gokin GK-4-78HGBD-780M 780W Solar Panel - Specs & Review | ComparePV" description: "Gokin GK-4-78HGBD-780M 780W solar panel. Specs: 24.30% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/gokin-gk-4-78hgbd-780m" updated: 2026-09-11 --- # Gokin GK-4-78HGBD-780M Efficiency leader, no clear weak spot 948 panels in the 680-880 W band, all technologies ## Identity - **Manufacturer:** Gokin - **Model:** GK-4-78HGBD-780M - **Series:** GK-4-78HGBD - **Rated power:** 780 W - **Cell technology:** Back Contact - **Bifacial:** yes ## How it compares Compared against 680-880 W band, all technologies (948 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 780 W | 710 W | Strong - top 1% | | | Module efficiency | 24.30% | 22.90% | Strong - top 1% | 131 | | Power density | 242.8 | 228.6 | Strong - top 2% | 138 | | Temperature coefficient | -0.260 | -0.290 | Typical | 511 | | Weight (kg) | 38.7 kg | 38.1 kg | Strong - top 12% | | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 24.30% | 22.90% | Strong - top 1% | 131 | | Power density | 242.8 | 228.6 | Strong - top 2% | 138 | | Temperature coefficient | -0.260 | -0.290 | Typical | 511 | | Weight per kWp | 49.6 | 53.4 | Strong - top 12% | 3,161 | | Performance warranty | 30 yrs | 30 yrs | Typical | 21 | ### Strengths - **24.30% module efficiency** - Top 1% of the 680-880 W band, against a median of 22.90%. Ranked 131st in the whole database. - **242.8 watts per square metre** - Top 2% of the 680-880 W band, against a median of 228.6. Ranked 138th in the whole database. - **49.6 kg per kWp** - Top 12% of the 680-880 W band, against a median of 53.4. - **Best for:** Utility-scale, commercial and hot-climate. ## Specification ### Electrical - **Rated power (Pmax):** 780 W - **Efficiency:** 24.30 % - **Voltage at Pmax (Vmp):** 48.97 V - **Current at Pmax (Imp):** 15.93 A - **Open-circuit voltage (Voc):** 58.92 V - **Short-circuit current (Isc):** 16.78 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.260 %/degC - **Temperature coefficient of Voc:** -0.220 %/degC - **Temperature coefficient of Isc:** 0.050 %/degC - **NOCT:** 45 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** Back Contact - **Cell count:** 156 - **Bifacial:** yes ### Physical - **Length:** 2465 mm - **Width:** 1303 mm - **Thickness:** 33 mm - **Weight:** 38.7 kg - **Area:** 3.21 m2 - **Power density:** 242.8 Wp/m2 ### Warranty and degradation - **Product warranty:** 15 years - **Performance warranty:** 30 years - **Output guaranteed at end of warranty:** 88.8 % - **First-year degradation:** 1.00 % - **Annual degradation:** 0.35 % - **Output after 30 years:** 693 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 131 of 14005 | | Power density | 138 of 14005 | | Temperature coefficient | 511 of 14005 | | Weight | 3161 of 14005 | | Warranty | 21 of 14005 | ## Pros - **Back Contact Technology with Zero Front-Side Shading** - Relocating all electrical contacts to the rear of the cell eliminates losses caused by front-grid shading. Combined with N-type architecture, this delivers module efficiency of 23.7–24.3% — surpassing peers such as Sunplus Hi-Max (24.1%) and Gamko GKA210N132 (24.14%) at a significantly higher unit power output of up to 780 Wp. - **Class A Fire Rating (Dual Glass)** - The module is certified Class A fire-resistant by virtue of its dual-glass construction, a requirement for rooftop installations with a pitch >18° near adjacent buildings and for the majority of European utility-scale tenders. Many competitors in this power class offer only Class C. - **Exceptional Mechanical Strength** - A certified static front-side load rating of 5,400 Pa (equivalent to ~550 kg/m²) and hail resistance of 25 mm diameter at 23 m/s meet the highest IEC requirements for ground-mounted systems in climatic zones subject to extreme weather conditions. - **30-Year Linear Power Output Warranty** - The manufacturer provides a 30-year linear power warranty, placing the series at the upper end of the current market standard. Comparable peers Sunplus Hi-Max and Gamko GKA210N132 do not publicly document equivalent warranty terms for the 750 Wp+ class, giving Gokin a competitive advantage in LCOE calculations for institutional investors. - **Confirmed Technology Partnership with AIKO** - In April 2026, Gokin and AIKO — a recognized leader in BC cell technology — announced an expanded strategic agreement covering BC commercialization. This provides Gokin with access to advanced cell know-how and validates the technological credibility of the GK-4-78HGBD series in the utility-scale market. ## Cons - **No BNEF Tier 1 Status (Bankability Gap)** - Gokin Solar does not appear on the BloombergNEF Tier 1 list, creating significant barriers to project finance for PV plants above 10 MW. This is a critical obstacle for the series' primary target segment — large-scale solar farms — where most EPCs and lenders mandate Tier-1 bankability as a contractual prerequisite. - **Efficiency Gap vs. AIKO Stellar 2N+78** - The closest direct comparable, AIKO Stellar 2N+78, delivers 25.1% efficiency and 805 Wp peak power versus Gokin's 24.3% / 780 Wp — a gap of 0.8 percentage points and 25 Wp. At the 10 MWp scale, this translates to approximately 312–400 additional modules required to achieve the same nameplate capacity, representing a measurable cost for investors optimizing land utilization. - **75% Bifaciality Factor — Low for BC Technology** - The declared bifaciality factor of ≤75% is on par with standard TOPCon modules, while advanced ABC cells from competitors (e.g., AIKO) achieve 85%+. In ground-mounted installations with high-albedo ground cover or on white-rooftop systems, this difference can result in 3–5% lower annual rear-side energy yield. ## About this series The Gokin GK-4-78HGBD series represents a breakthrough in efficiency thanks to the use of **N-type TOPCon technology**, which eliminates the problem of light-induced degradation and guarantees stable operation for decades. The use of **bifacial dual glass construction** allows for efficient energy harvesting not only directly from the sun but also from radiation reflected from the ground, which significantly increases the total annual energy yield. These modules solve the problem of limited installation space by offering high power density while maintaining exceptional resistance to extreme weather conditions, such as strong winds or snow loads. A distinguishing feature of the series is its excellent temperature coefficient, ensuring that the panels maintain high efficiency even on hot days when traditional cells lose performance. This solution is primarily dedicated to **large-scale photovoltaic farms** and demanding business installations where maximum return on investment and component durability are key. The Gokin GK-4-78HGBD stands out from the competition through precise optimization of the production process, which translates into **minimal losses at cell interconnections** and better performance characteristics in low-light conditions. By choosing this series, investors gain technological certainty backed by an innovative 78-cell structure that redefines the standards of modern solar energy. ## Notable figures - Efficiency of 24.3% matches the \*\*Back Contact 750-800W\*\* median - At 242.8 W/m² power density, roof space requirements are typical for \*\*Back Contact 750-800W\*\* panels - Temperature coefficient of -0.26%/°C matches the \*\*Back Contact 750-800W\*\* median - At 38.7 kg, this panel is 1.1 kg lighter than \*\*Back Contact 750-800W\*\* median (39.8 kg) - easier handling during installation - 70% bifaciality enables rear-side power generation, boosting yield by 4-10% on reflective surfaces ## Questions ### What is Back Contact technology in the Gokin GK-4-78HGBD panels and how does it differ from conventional cells? In Back Contact technology, all electrical contacts are relocated to the rear side of the cell, leaving the entire front surface fully photoelectrically active. The Gokin GK-4-78HGBD achieves module efficiency of 23.7–24.3% by eliminating power losses caused by shading from metallic busbars. This is one of the key reasons the series generates more energy per square meter than typical TOPCon or PERC modules. ### How much additional energy does the bifacial dual-glass design of the Gokin GK-4-78HGBD series produce? The GK-4-78HGBD module features a bifaciality factor of up to 75%, meaning the rear glass can capture up to 75% of the energy relative to the front side. In practice, installations over high-albedo surfaces — such as concrete, light-colored membranes, or gravel — yield a real-world energy gain of approximately 5–15% per year compared to a monofacial panel of the same rated power. ### What warranty applies to the Gokin GK-4-78HGBD panels and what exactly does it cover? The manufacturer provides a 15-year product warranty covering material and workmanship defects, along with a 30-year linear power output warranty. This means the panel's output will remain no lower than the values specified in the degradation schedule for three full decades. The dual-glass construction additionally protects the cells against moisture ingress, further reinforcing the module's real-world durability beyond the stated warranty terms. ### Does the Gokin GK-4-78HGBD series perform well on hot days and under overcast conditions? Yes. Back Contact technology exhibits a more favorable temperature coefficient than standard PERC cells, so the panel loses less power at elevated operating temperatures. The module operates across a temperature range of -40°C to +85°C. The bifacial cell architecture also improves energy yield under diffuse irradiance, which is particularly relevant under the frequently overcast sky conditions typical of the Polish climate. ### What type of installation is the Gokin GK-4-78HGBD series designed for — is it suitable for a single-family home? The GK-4-78HGBD series is designed primarily for utility-scale solar farms and commercial & industrial (C&I) installations. The module weighs 38.7 kg and measures 2,465 × 1,303 mm, which makes handling and mounting on a typical residential pitched roof impractical. Residential prosumers would be considerably better served by smaller and lighter panels from Gokin's portfolio or from other manufacturers. ### What mechanical loads can the Gokin GK-4-78HGBD panel withstand — will it handle a Polish winter and high winds? The module is certified for a static mechanical load of 5,400 Pa on the front side and 2,400 Pa on the rear side, corresponding to resistance against extreme snow accumulation and high wind pressures. It has also passed hail impact testing: ice balls 25 mm in diameter at a velocity of 23 m/s cause no damage. For Polish climatic conditions, these specifications provide a substantial safety margin well above the requirements of applicable building standards. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/GK-4-78HGBD-SF-DG-F1_EN-1286e59862a6.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [AIKO AIKO-A805-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a805-grh78dw) | 805 W | +25 W, heavier, +0.8 pp | | [AIKO AIKO-A800-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a800-grh78dw) | 800 W | +20 W, heavier, +0.6 pp | | [AIKO AIKO-A795-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a795-grh78dw) | 795 W | +15 W, heavier, +0.5 pp | | [AIKO AIKO-A790-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a790-grh78dw) | 790 W | +10 W, heavier, +0.3 pp | | [Trina Solar TSM-NEG21C.20Q-760](https://comparepv.com/panel/trina-solar-tsm-neg21c-20q-760) | 760 W | -20 W | | [AIKO AIKO-A785-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a785-grh78dw) | 785 W | Heavier | | [AIKO AIKO-A780-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a780-grh78dw) | 780 W | Heavier | | [Jetion JT755SLk(B)](https://comparepv.com/panel/jetion-jt755slk-b) | 755 W | -25 W, cooler, lighter | | [Trina Solar TSM-NEG21C.20Q-755](https://comparepv.com/panel/trina-solar-tsm-neg21c-20q-755) | 755 W | -25 W | | [Gokin GK-4-78HGBD-760M](https://comparepv.com/panel/gokin-gk-4-78hgbd-760m) | 760 W | -20 W, -0.6 pp | | [Gokin GK-4-78HGBD-765M](https://comparepv.com/panel/gokin-gk-4-78hgbd-765m) | 765 W | -15 W, -0.5 pp | | [Gokin GK-4-78HGBD-770M](https://comparepv.com/panel/gokin-gk-4-78hgbd-770m) | 770 W | -10 W, -0.3 pp | | [Gokin GK-4-78HGBD-775M](https://comparepv.com/panel/gokin-gk-4-78hgbd-775m) | 775 W | Very close match | --- Source: https://comparepv.com/panel/gokin-gk-4-78hgbd-780m 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.