--- title: "AIKO AIKO-A785-GRH78Dw vs Gokin GK-4-78HGBD-780M - Solar Panel Comparison | ComparePV" description: "Compare AIKO AIKO-A785-GRH78Dw vs Gokin GK-4-78HGBD-780M side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/aiko-aiko-a785-grh78dw/gokin-gk-4-78hgbd-780m" updated: 2026-09-11 --- # AIKO AIKO-A785-GRH78Dw vs Gokin GK-4-78HGBD-780M GK-4-78HGBD-780M leads on the differences that matter The largest is weight: 1.1 kg lighter. 17 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [AIKO AIKO-A785-GRH78Dw](https://comparepv.com/panel/aiko-aiko-a785-grh78dw) | [Gokin GK-4-78HGBD-780M](https://comparepv.com/panel/gokin-gk-4-78hgbd-780m) | | Manufacturer | AIKO | Gokin | | Power | 785 Wp | 780 Wp | | Efficiency | 24.40 % | 24.30 % | | Technology | Back Contact | Back Contact | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | AIKO-A785-GRH78Dw | GK-4-78HGBD-780M | Difference | | --- | --- | --- | --- | | Weight | 39.8 kg | 38.7 kg | -1.1 kg for GK-4-78HGBD-780M | ## Every compared parameter | Parameter | AIKO-A785-GRH78Dw | GK-4-78HGBD-780M | | --- | --- | --- | | Rated power | 785 Wp | 780 Wp | | Module efficiency | 24.40 % | 24.30 % | | Power density | 244.4 Wp/m² | 242.8 Wp/m² | | Open-circuit voltage | 59.02 V | 58.92 V | | Voltage at max power | 49.07 V | 48.97 V | | Short-circuit current | 16.85 A | 16.78 A | | Current at max power | 16.00 A | 15.93 A | | Temperature coefficient | -0.260 %/°C | -0.260 %/°C | | Dimensions | 2465x1303x33 mm | 2465x1303x33 mm | | Module area | 3.212 m² | 3.212 m² | | Weight | 39.8 kg | 38.7 kg | | Weight per kWp | 50.7 kg/kWp | 49.6 kg/kWp | | Product warranty | 15 yrs | 15 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | - | 0.35 %/yr | | Cell technology | Back Contact | Back Contact | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 156 | 156 | | Bifacial | Yes | Yes | ## Thirty-year yield A 1.0% first-year loss then 0.40% a year, assumed for both panels, at 1,200 kWh/kWp a year Same temp coeff. for both panels (-0.260 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other. - **Cumulative output, AIKO-A785-GRH78Dw:** 26,338 kWh - **Cumulative output, GK-4-78HGBD-780M:** 26,171 kWh - **Gap:** 167 kWh ## Output when hot | Condition | Cell temperature | AIKO-A785-GRH78Dw | GK-4-78HGBD-780M | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 785 W | 780 W | 100.0% of rated power | | Cool, bright day | 40 °C | 754 W | 750 W | 96.1% of rated power | | Typical summer roof | 55 °C | 724 W | 719 W | 92.2% of rated power | | Hot roof | 70 °C | 693 W | 689 W | 88.3% of rated power | ## Against the whole database | Measure | AIKO-A785-GRH78Dw | GK-4-78HGBD-780M | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #99 | #131 | 14,005 | AIKO-A785-GRH78Dw leads by 32 places | | Power density | #87 | #138 | 14,005 | AIKO-A785-GRH78Dw leads by 51 places | | Heat behaviour | #511 | #511 | 14,005 | Tied - the same position in the database | | Weight | #4,120 | #3,161 | 14,005 | GK-4-78HGBD-780M leads by 959 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #10 | #15 | 14,005 | AIKO-A785-GRH78Dw leads by 5 places | ## Questions ### Which panel is better: AIKO AIKO-A785-GRH78Dw or Gokin GK-4-78HGBD-780M? According to our database: **AIKO AIKO-A785-GRH78Dw** has higher module efficiency (**24.40%** vs **24.30%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of AIKO AIKO-A785-GRH78Dw and Gokin GK-4-78HGBD-780M? **AIKO AIKO-A785-GRH78Dw** has a module efficiency of **24.40%**, while **Gokin GK-4-78HGBD-780M** is **24.30%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does AIKO AIKO-A785-GRH78Dw use vs Gokin GK-4-78HGBD-780M? **AIKO AIKO-A785-GRH78Dw** uses **Back Contact** cells; **Gokin GK-4-78HGBD-780M** uses **Back Contact**. Modern **n-type** technologies (**TOPCon**, **HJT**, BC) typically deliver higher efficiency and lower degradation compared to older **PERC** (p-type) cells. ### What is the warranty on AIKO AIKO-A785-GRH78Dw and Gokin GK-4-78HGBD-780M? **AIKO AIKO-A785-GRH78Dw** has a **30 years** power warranty; **Gokin GK-4-78HGBD-780M** has a **30 years** power warranty. The power warranty guarantees a minimum percentage of rated output at the end of the warranty period (typically 80**-87%**). Product (materials) warranties are usually shorter. ### Are AIKO AIKO-A785-GRH78Dw and Gokin GK-4-78HGBD-780M bifacial panels? Both **AIKO AIKO-A785-GRH78Dw** and **Gokin GK-4-78HGBD-780M** are bifacial - they capture reflected light from the ground, which can add 5**-15%** more annual energy on ground-mount or elevated rooftop installations with a light surface beneath. ## Related comparisons - [AIKO AIKO-A785-GRH78Dw vs AIKO AIKO-A805-GRH78Dw](https://comparepv.com/compare/aiko-aiko-a785-grh78dw/aiko-aiko-a805-grh78dw) - 3 differences, the largest is module efficiency - [AIKO AIKO-A785-GRH78Dw vs AIKO AIKO-A800-GRH78Dw](https://comparepv.com/compare/aiko-aiko-a785-grh78dw/aiko-aiko-a800-grh78dw) - 3 differences, the largest is module efficiency - [AIKO AIKO-A785-GRH78Dw vs AIKO AIKO-A795-GRH78Dw](https://comparepv.com/compare/aiko-aiko-a785-grh78dw/aiko-aiko-a795-grh78dw) - 3 differences, the largest is module efficiency - [AIKO AIKO-A785-GRH78Dw vs AIKO AIKO-A790-GRH78Dw](https://comparepv.com/compare/aiko-aiko-a785-grh78dw/aiko-aiko-a790-grh78dw) - One difference: module efficiency - [AIKO AIKO-A785-GRH78Dw vs AIKO AIKO-A780-GRH78Dw](https://comparepv.com/compare/aiko-aiko-a785-grh78dw/aiko-aiko-a780-grh78dw) - The same specification on paper - [AIKO AIKO-A785-GRH78Dw vs AIKO AIKO-A775-GRH78Dw](https://comparepv.com/compare/aiko-aiko-a785-grh78dw/aiko-aiko-a775-grh78dw) - 3 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/aiko-aiko-a785-grh78dw/gokin-gk-4-78hgbd-780m Not in this file, on the page: the thirty-year yield curve year by year at a cell temperature you pick and a written summary generated on request.