--- title: "Waaree WSMD-660 vs Waaree WSMDi-405 - Solar Panel Comparison | ComparePV" description: "Compare Waaree WSMD-660 vs Waaree WSMDi-405 side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/waaree-wsmd-660/waaree-wsmdi-405" updated: 2026-09-11 --- # Waaree WSMD-660 vs Waaree WSMDi-405 WSMD-660 leads on the differences that matter The largest is module efficiency: 0.85 pp more efficient. 9 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Waaree WSMD-660](https://comparepv.com/panel/waaree-wsmd-660) | [Waaree WSMDi-405](https://comparepv.com/panel/waaree-wsmdi-405) | | Manufacturer | Waaree | Waaree | | Power | 660 Wp | 405 Wp | | Efficiency | 21.13 % | 20.28 % | | Technology | PERC | PERC | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | WSMD-660 | WSMDi-405 | Difference | | --- | --- | --- | --- | | Module efficiency | 21.13 % | 20.28 % | +0.85 pp for WSMD-660 | | Rated power | 660 Wp | 405 Wp | +255 W for WSMD-660 | | Temperature coefficient | -0.340 %/°C | -0.365 %/°C | +0.025 %/°C for WSMD-660 | | Weight | 34.5 kg | 22.0 kg | -12.5 kg for WSMDi-405 | | Power density | 211.2 Wp/m² | 202.8 Wp/m² | +8.4 Wp/m² for WSMD-660 | | Short-circuit current | 17.98 A | 11.40 A | 6.58 A apart | | Module area | 3.125 m² | 1.997 m² | 1.128 m² apart | | Current at max power | 17.35 A | 10.61 A | 6.74 A apart | | Weight per kWp | 52.3 kg/kWp | 54.3 kg/kWp | -2.0 kg/kWp for WSMD-660 | | Dimensions | 2400x1302x35 mm | 1924x1038x35 mm | 2400x1302x35 mm vs 1924x1038x35 mm | ## Every compared parameter | Parameter | WSMD-660 | WSMDi-405 | | --- | --- | --- | | Rated power | 660 Wp | 405 Wp | | Module efficiency | 21.13 % | 20.28 % | | Power density | 211.2 Wp/m² | 202.8 Wp/m² | | Open-circuit voltage | 46.40 V | 45.44 V | | Voltage at max power | 38.06 V | 38.22 V | | Short-circuit current | 17.98 A | 11.40 A | | Current at max power | 17.35 A | 10.61 A | | Temperature coefficient | -0.340 %/°C | -0.365 %/°C | | Dimensions | 2400x1302x35 mm | 1924x1038x35 mm | | Module area | 3.125 m² | 1.997 m² | | Weight | 34.5 kg | 22.0 kg | | Weight per kWp | 52.3 kg/kWp | 54.3 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 27 yrs | 27 yrs | | Annual degradation | 0.55 %/yr | 0.55 %/yr | | Cell technology | PERC | PERC | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 132 | | Bifacial | No | No | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year - **Cumulative output, WSMD-660:** 21,390 kWh - **Cumulative output, WSMDi-405:** 13,126 kWh - **Gap:** 8,264 kWh ## Output when hot | Condition | Cell temperature | WSMD-660 | WSMDi-405 | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 660 W | 405 W | 100.0% of rated power | | Cool, bright day | 40 °C | 626 W | 383 W | 94.5% of rated power | | Typical summer roof | 55 °C | 593 W | 361 W | 89.0% of rated power | | Hot roof | 70 °C | 559 W | 338 W | 83.6% of rated power | ## Against the whole database | Measure | WSMD-660 | WSMDi-405 | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #9,239 | #11,853 | 14,005 | WSMD-660 leads by 2,614 places | | Power density | #9,251 | #11,821 | 14,005 | WSMD-660 leads by 2,570 places | | Heat behaviour | #8,778 | #13,045 | 14,005 | WSMD-660 leads by 4,267 places | | Weight | #5,732 | #8,586 | 14,005 | WSMD-660 leads by 2,854 places | | Warranty | #9,667 | #9,667 | 14,005 | Tied - the same position in the database | | Overall | #3,874 | #11,980 | 14,005 | WSMD-660 leads by 8,106 places | ## Questions ### Which panel is better: Waaree WSMD-660 or Waaree WSMDi-405? According to our database: **Waaree WSMD-660** has higher module efficiency (**21.13%** vs **20.28%**); **Waaree WSMD-660** tolerates heat better (temp coeff **-0.340%/°C** vs **-0.365%/°C**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Waaree WSMD-660 and Waaree WSMDi-405? **Waaree WSMD-660** has a module efficiency of **21.13%**, while **Waaree WSMDi-405** is **20.28%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Waaree WSMD-660 use vs Waaree WSMDi-405? **Waaree WSMD-660** uses **PERC** cells; **Waaree WSMDi-405** uses **PERC**. 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 Waaree WSMD-660 and Waaree WSMDi-405? **Waaree WSMD-660** has a **27 years** power warranty; **Waaree WSMDi-405** has a **27 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. ## Related comparisons - [Waaree WSMD-660 vs Waaree WSMD-665](https://comparepv.com/compare/waaree-wsmd-660/waaree-wsmd-665) - The same specification on paper - [Waaree WSMD-660 vs Waaree WSMD-655](https://comparepv.com/compare/waaree-wsmd-660/waaree-wsmd-655) - The same specification on paper - [Waaree WSMD-660 vs Waaree WSMD-650](https://comparepv.com/compare/waaree-wsmd-660/waaree-wsmd-650) - 3 differences, the largest is module efficiency - [Waaree WSMD-660 vs Waaree WSMD-645](https://comparepv.com/compare/waaree-wsmd-660/waaree-wsmd-645) - 3 differences, the largest is module efficiency - [Waaree WSMD-660 vs Waaree WSMD-545](https://comparepv.com/compare/waaree-wsmd-660/waaree-wsmd-545) - 10 differences, the largest is rated power - [Waaree WSMD-660 vs Waaree WSMD-540](https://comparepv.com/compare/waaree-wsmd-660/waaree-wsmd-540) - 10 differences, the largest is rated power --- Source: https://comparepv.com/compare/waaree-wsmd-660/waaree-wsmdi-405 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.