--- title: "AIKO AIKO-A645-GRH66Dw vs AIKO AIKO-G660-MCH72Dw - Solar Panel Comparison | ComparePV" description: "Compare AIKO AIKO-A645-GRH66Dw vs AIKO AIKO-G660-MCH72Dw 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-a645-grh66dw/aiko-aiko-g660-mch72dw" updated: 2026-09-11 --- # AIKO AIKO-A645-GRH66Dw vs AIKO AIKO-G660-MCH72Dw G660-MCH72Dw leads on the differences that matter The largest is module efficiency: 0.50 pp more efficient. 10 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [AIKO AIKO-A645-GRH66Dw](https://comparepv.com/panel/aiko-aiko-a645-grh66dw) | [AIKO AIKO-G660-MCH72Dw](https://comparepv.com/panel/aiko-aiko-g660-mch72dw) | | Manufacturer | AIKO | AIKO | | Power | 645 Wp | 660 Wp | | Efficiency | 23.90 % | 24.40 % | | Technology | Back Contact | Back Contact | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | A645-GRH66Dw | G660-MCH72Dw | Difference | | --- | --- | --- | --- | | Module efficiency | 23.90 % | 24.40 % | +0.50 pp for G660-MCH72Dw | | Open-circuit voltage | 49.20 V | 54.20 V | 5.00 V apart | | Power density | 238.8 Wp/m² | 244.3 Wp/m² | +5.6 Wp/m² for G660-MCH72Dw | | Rated power | 645 Wp | 660 Wp | +15 W for G660-MCH72Dw | | Short-circuit current | 16.55 A | 15.18 A | 1.37 A apart | | Cell count | 132 | 144 | 12 cells apart | | Voltage at max power | 41.90 V | 45.50 V | 3.60 V apart | | Weight | 32.5 kg | 33.5 kg | -1.0 kg for A645-GRH66Dw | | Current at max power | 15.40 A | 14.51 A | 0.89 A apart | ## Every compared parameter | Parameter | A645-GRH66Dw | G660-MCH72Dw | | --- | --- | --- | | Rated power | 645 Wp | 660 Wp | | Module efficiency | 23.90 % | 24.40 % | | Power density | 238.8 Wp/m² | 244.3 Wp/m² | | Open-circuit voltage | 49.20 V | 54.20 V | | Voltage at max power | 41.90 V | 45.50 V | | Short-circuit current | 16.55 A | 15.18 A | | Current at max power | 15.40 A | 14.51 A | | Temperature coefficient | -0.260 %/°C | -0.260 %/°C | | Dimensions | 2382x1134x30 mm | 2382x1134x30 mm | | Module area | 2.701 m² | 2.701 m² | | Weight | 32.5 kg | 33.5 kg | | Weight per kWp | 50.4 kg/kWp | 50.8 kg/kWp | | Product warranty | 15 yrs | 15 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.35 %/yr | 0.35 %/yr | | Cell technology | Back Contact | Back Contact | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 144 | | Bifacial | Yes | Yes | ## Thirty-year yield Each panel's own declared degradation curve, 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, A645-GRH66Dw:** 21,809 kWh - **Cumulative output, G660-MCH72Dw:** 22,317 kWh - **Gap:** 508 kWh ## Output when hot | Condition | Cell temperature | A645-GRH66Dw | G660-MCH72Dw | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 645 W | 660 W | 100.0% of rated power | | Cool, bright day | 40 °C | 620 W | 634 W | 96.1% of rated power | | Typical summer roof | 55 °C | 595 W | 609 W | 92.2% of rated power | | Hot roof | 70 °C | 570 W | 583 W | 88.3% of rated power | ## Against the whole database | Measure | A645-GRH66Dw | G660-MCH72Dw | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #351 | #99 | 14,005 | G660-MCH72Dw leads by 252 places | | Power density | #356 | #88 | 14,005 | G660-MCH72Dw leads by 268 places | | Heat behaviour | #511 | #511 | 14,005 | Tied - the same position in the database | | Weight | #3,767 | #4,172 | 14,005 | A645-GRH66Dw leads by 405 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #1,073 | #576 | 14,005 | G660-MCH72Dw leads by 497 places | ## Questions ### Which panel is better: AIKO AIKO-A645-GRH66Dw or AIKO AIKO-G660-MCH72Dw? According to our database: **AIKO AIKO-G660-MCH72Dw** has higher module efficiency (**24.40%** vs **23.90%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of AIKO AIKO-A645-GRH66Dw and AIKO AIKO-G660-MCH72Dw? **AIKO AIKO-A645-GRH66Dw** has a module efficiency of **23.90%**, while **AIKO AIKO-G660-MCH72Dw** is **24.40%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does AIKO AIKO-A645-GRH66Dw use vs AIKO AIKO-G660-MCH72Dw? **AIKO AIKO-A645-GRH66Dw** uses **Back Contact** cells; **AIKO AIKO-G660-MCH72Dw** 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-A645-GRH66Dw and AIKO AIKO-G660-MCH72Dw? **AIKO AIKO-A645-GRH66Dw** has a **30 years** power warranty; **AIKO AIKO-G660-MCH72Dw** 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-A645-GRH66Dw and AIKO AIKO-G660-MCH72Dw bifacial panels? Both **AIKO AIKO-A645-GRH66Dw** and **AIKO AIKO-G660-MCH72Dw** 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-A645-GRH66Dw vs AIKO AIKO-A660-GRH66Dw](https://comparepv.com/compare/aiko-aiko-a645-grh66dw/aiko-aiko-a660-grh66dw) - 3 differences, the largest is module efficiency - [AIKO AIKO-A645-GRH66Dw vs AIKO AIKO-A655-GRH66Dw](https://comparepv.com/compare/aiko-aiko-a645-grh66dw/aiko-aiko-a655-grh66dw) - 3 differences, the largest is module efficiency - [AIKO AIKO-A645-GRH66Dw vs AIKO AIKO-A650-GRH66Dw](https://comparepv.com/compare/aiko-aiko-a645-grh66dw/aiko-aiko-a650-grh66dw) - One difference: module efficiency - [AIKO AIKO-A645-GRH66Dw vs AIKO AIKO-A640-GRH66Dw](https://comparepv.com/compare/aiko-aiko-a645-grh66dw/aiko-aiko-a640-grh66dw) - One difference: module efficiency - [AIKO AIKO-G660-MCH72Dw vs AIKO AIKO-G655-MCH72Dw](https://comparepv.com/compare/aiko-aiko-g660-mch72dw/aiko-aiko-g655-mch72dw) - One difference: module efficiency - [AIKO AIKO-G660-MCH72Dw vs AIKO AIKO-G650-MCH72Dw](https://comparepv.com/compare/aiko-aiko-g660-mch72dw/aiko-aiko-g650-mch72dw) - 3 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/aiko-aiko-a645-grh66dw/aiko-aiko-g660-mch72dw 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.