--- title: "Waaree WSMD-650 vs Waaree WSMD-660 - Solar Panel Comparison | ComparePV" description: "Compare Waaree WSMD-650 vs Waaree WSMD-660 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-650/waaree-wsmd-660" updated: 2026-09-11 --- # Waaree WSMD-650 vs Waaree WSMD-660 660 leads on the differences that matter The largest is module efficiency: 0.31 pp more efficient. 16 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Waaree WSMD-650](https://comparepv.com/panel/waaree-wsmd-650) | [Waaree WSMD-660](https://comparepv.com/panel/waaree-wsmd-660) | | Manufacturer | Waaree | Waaree | | Power | 650 Wp | 660 Wp | | Efficiency | 20.82 % | 21.13 % | | Technology | PERC | PERC | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 650 | 660 | Difference | | --- | --- | --- | --- | | Module efficiency | 20.82 % | 21.13 % | +0.31 pp for 660 | | Power density | 208.0 Wp/m² | 211.2 Wp/m² | +3.2 Wp/m² for 660 | | Rated power | 650 Wp | 660 Wp | +10 W for 660 | ## Every compared parameter | Parameter | 650 | 660 | | --- | --- | --- | | Rated power | 650 Wp | 660 Wp | | Module efficiency | 20.82 % | 21.13 % | | Power density | 208.0 Wp/m² | 211.2 Wp/m² | | Open-circuit voltage | 46.09 V | 46.40 V | | Voltage at max power | 37.91 V | 38.06 V | | Short-circuit current | 17.84 A | 17.98 A | | Current at max power | 17.16 A | 17.35 A | | Temperature coefficient | -0.340 %/°C | -0.340 %/°C | | Dimensions | 2400x1302x35 mm | 2400x1302x35 mm | | Module area | 3.125 m² | 3.125 m² | | Weight | 34.5 kg | 34.5 kg | | Weight per kWp | 53.1 kg/kWp | 52.3 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 Same temp coeff. for both panels (-0.340 %/°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, 650:** 21,066 kWh - **Cumulative output, 660:** 21,390 kWh - **Gap:** 324 kWh ## Output when hot | Condition | Cell temperature | 650 | 660 | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 650 W | 660 W | 100.0% of rated power | | Cool, bright day | 40 °C | 617 W | 626 W | 94.9% of rated power | | Typical summer roof | 55 °C | 584 W | 593 W | 89.8% of rated power | | Hot roof | 70 °C | 551 W | 559 W | 84.7% of rated power | ## Against the whole database | Measure | 650 | 660 | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #10,443 | #9,239 | 14,005 | 660 leads by 1,204 places | | Power density | #10,477 | #9,251 | 14,005 | 660 leads by 1,226 places | | Heat behaviour | #8,778 | #8,778 | 14,005 | Tied - the same position in the database | | Weight | #6,836 | #5,732 | 14,005 | 660 leads by 1,104 places | | Warranty | #9,667 | #9,667 | 14,005 | Tied - the same position in the database | | Overall | #4,615 | #3,874 | 14,005 | 660 leads by 741 places | ## Questions ### Which panel is better: Waaree WSMD-650 or Waaree WSMD-660? According to our database: **Waaree WSMD-660** has higher module efficiency (**21.13%** vs **20.82%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Waaree WSMD-650 and Waaree WSMD-660? **Waaree WSMD-650** has a module efficiency of **20.82%**, while **Waaree WSMD-660** is **21.13%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Waaree WSMD-650 use vs Waaree WSMD-660? **Waaree WSMD-650** uses **PERC** cells; **Waaree WSMD-660** 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-650 and Waaree WSMD-660? **Waaree WSMD-650** has a **27 years** power warranty; **Waaree WSMD-660** 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-650 vs Waaree WSMD-665](https://comparepv.com/compare/waaree-wsmd-650/waaree-wsmd-665) - 3 differences, the largest is module efficiency - [Waaree WSMD-650 vs Waaree WSMD-655](https://comparepv.com/compare/waaree-wsmd-650/waaree-wsmd-655) - The same specification on paper - [Waaree WSMD-650 vs Waaree WSMD-645](https://comparepv.com/compare/waaree-wsmd-650/waaree-wsmd-645) - The same specification on paper - [Waaree WSMD-650 vs Waaree WSMD-545](https://comparepv.com/compare/waaree-wsmd-650/waaree-wsmd-545) - 13 differences, the largest is rated power - [Waaree WSMD-650 vs Waaree WSMD-540](https://comparepv.com/compare/waaree-wsmd-650/waaree-wsmd-540) - 11 differences, the largest is rated power - [Waaree WSMD-650 vs Waaree WSMD-535](https://comparepv.com/compare/waaree-wsmd-650/waaree-wsmd-535) - 10 differences, the largest is rated power --- Source: https://comparepv.com/compare/waaree-wsmd-650/waaree-wsmd-660 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.