--- title: "Waaree Bi-68-645 vs Waaree Bi-68-660 - Solar Panel Comparison | ComparePV" description: "Compare Waaree Bi-68-645 vs Waaree Bi-68-660 side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/waaree-bi-68-645/waaree-bi-68-660" updated: 2026-09-11 --- # Waaree Bi-68-645 vs Waaree Bi-68-660 660 leads on the differences that matter The largest is module efficiency: 0.48 pp more efficient. 16 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Waaree Bi-68-645](https://comparepv.com/panel/waaree-bi-68-645) | [Waaree Bi-68-660](https://comparepv.com/panel/waaree-bi-68-660) | | Manufacturer | Waaree | Waaree | | Power | 645 Wp | 660 Wp | | Efficiency | 20.65 % | 21.13 % | | Technology | PERC | PERC | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 645 | 660 | Difference | | --- | --- | --- | --- | | Module efficiency | 20.65 % | 21.13 % | +0.48 pp for 660 | | Power density | 206.4 Wp/m² | 211.2 Wp/m² | +4.8 Wp/m² for 660 | | Rated power | 645 Wp | 660 Wp | +15 W for 660 | ## Every compared parameter | Parameter | 645 | 660 | | --- | --- | --- | | Rated power | 645 Wp | 660 Wp | | Module efficiency | 20.65 % | 21.13 % | | Power density | 206.4 Wp/m² | 211.2 Wp/m² | | Open-circuit voltage | 45.94 V | 46.40 V | | Voltage at max power | 37.87 V | 38.06 V | | Short-circuit current | 17.78 A | 17.98 A | | Current at max power | 17.04 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 | 39.0 kg | 39.0 kg | | Weight per kWp | 60.5 kg/kWp | 59.1 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.55 %/yr | 0.55 %/yr | | Cell technology | PERC | PERC | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 132 | | 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 (-0.340 %/°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, 645:** 20,904 kWh - **Cumulative output, 660:** 21,390 kWh - **Gap:** 486 kWh ## Output when hot | Condition | Cell temperature | 645 | 660 | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 645 W | 660 W | 100.0% of rated power | | Cool, bright day | 40 °C | 612 W | 626 W | 94.9% of rated power | | Typical summer roof | 55 °C | 579 W | 593 W | 89.8% of rated power | | Hot roof | 70 °C | 546 W | 559 W | 84.7% of rated power | ## Against the whole database | Measure | 645 | 660 | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #11,014 | #9,239 | 14,005 | 660 leads by 1,775 places | | Power density | #11,023 | #9,251 | 14,005 | 660 leads by 1,772 places | | Heat behaviour | #8,778 | #8,778 | 14,005 | Tied - the same position in the database | | Weight | #12,467 | #12,010 | 14,005 | 660 leads by 457 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #4,408 | #3,318 | 14,005 | 660 leads by 1,090 places | ## Questions ### Which panel is better: Waaree Bi-68-645 or Waaree Bi-68-660? According to our database: **Waaree Bi-68-660** has higher module efficiency (**21.13%** vs **20.65%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Waaree Bi-68-645 and Waaree Bi-68-660? **Waaree Bi-68-645** has a module efficiency of **20.65%**, while **Waaree Bi-68-660** is **21.13%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Waaree Bi-68-645 use vs Waaree Bi-68-660? **Waaree Bi-68-645** uses **PERC** cells; **Waaree Bi-68-660** 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 Bi-68-645 and Waaree Bi-68-660? **Waaree Bi-68-645** has a **30 years** power warranty; **Waaree Bi-68-660** 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 Waaree Bi-68-645 and Waaree Bi-68-660 bifacial panels? Both **Waaree Bi-68-645** and **Waaree Bi-68-660** 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 - [Waaree Bi-68-645 vs Waaree Bi-68-665](https://comparepv.com/compare/waaree-bi-68-645/waaree-bi-68-665) - 3 differences, the largest is module efficiency - [Waaree Bi-68-645 vs Waaree Bi-68-655](https://comparepv.com/compare/waaree-bi-68-645/waaree-bi-68-655) - 3 differences, the largest is module efficiency - [Waaree Bi-68-645 vs Waaree Bi-68-650](https://comparepv.com/compare/waaree-bi-68-645/waaree-bi-68-650) - The same specification on paper - [Waaree Bi-68-645 vs Waaree Bi-66-600](https://comparepv.com/compare/waaree-bi-68-645/waaree-bi-66-600) - 9 differences, the largest is rated power - [Waaree Bi-68-645 vs Waaree Bi-66-595](https://comparepv.com/compare/waaree-bi-68-645/waaree-bi-66-595) - 8 differences, the largest is rated power - [Waaree Bi-68-645 vs Waaree Bi-66-590](https://comparepv.com/compare/waaree-bi-68-645/waaree-bi-66-590) - 7 differences, the largest is rated power --- Source: https://comparepv.com/compare/waaree-bi-68-645/waaree-bi-68-660 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.