--- title: "Ulica Solar TSM156-9-635BNDG vs Ulica Solar TSM156-9-640BNDG - Solar Panel Comparison | ComparePV" description: "Compare Ulica Solar TSM156-9-635BNDG vs Ulica Solar TSM156-9-640BNDG side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/ulica-solar-tsm156-9-635bndg/ulica-solar-tsm156-9-640bndg" updated: 2026-09-11 --- # Ulica Solar TSM156-9-635BNDG vs Ulica Solar TSM156-9-640BNDG 640BNDG leads on the differences that matter The largest is module efficiency: 0.20 pp more efficient. 18 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Ulica Solar TSM156-9-635BNDG](https://comparepv.com/panel/ulica-solar-tsm156-9-635bndg) | [Ulica Solar TSM156-9-640BNDG](https://comparepv.com/panel/ulica-solar-tsm156-9-640bndg) | | Manufacturer | Ulica Solar | Ulica Solar | | Power | 635 Wp | 640 Wp | | Efficiency | 22.70 % | 22.90 % | | Technology | TOPCon | TOPCon | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 635BNDG | 640BNDG | Difference | | --- | --- | --- | --- | | Module efficiency | 22.70 % | 22.90 % | +0.20 pp for 640BNDG | ## Every compared parameter | Parameter | 635BNDG | 640BNDG | | --- | --- | --- | | Rated power | 635 Wp | 640 Wp | | Module efficiency | 22.70 % | 22.90 % | | Power density | 227.2 Wp/m² | 229.0 Wp/m² | | Open-circuit voltage | 56.40 V | 56.60 V | | Voltage at max power | 47.15 V | 47.31 V | | Short-circuit current | 14.33 A | 14.38 A | | Current at max power | 13.48 A | 13.54 A | | Temperature coefficient | -0.290 %/°C | -0.290 %/°C | | Dimensions | 2465x1134x30 mm | 2465x1134x30 mm | | Module area | 2.795 m² | 2.795 m² | | Weight | 33.5 kg | 33.5 kg | | Weight per kWp | 52.8 kg/kWp | 52.3 kg/kWp | | Product warranty | 5 yrs | 5 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.40 %/yr | | Cell technology | TOPCon | TOPCon | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 156 | 156 | | 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 (-0.290 %/°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, 635BNDG:** 21,306 kWh - **Cumulative output, 640BNDG:** 21,473 kWh - **Gap:** 167 kWh ## Output when hot | Condition | Cell temperature | 635BNDG | 640BNDG | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 635 W | 640 W | 100.0% of rated power | | Cool, bright day | 40 °C | 607 W | 612 W | 95.7% of rated power | | Typical summer roof | 55 °C | 580 W | 584 W | 91.3% of rated power | | Hot roof | 70 °C | 552 W | 556 W | 87.0% of rated power | ## Against the whole database | Measure | 635BNDG | 640BNDG | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #3,307 | #2,359 | 14,005 | 640BNDG leads by 948 places | | Power density | #3,252 | #2,389 | 14,005 | 640BNDG leads by 863 places | | Heat behaviour | #2,165 | #2,165 | 14,005 | Tied - the same position in the database | | Weight | #6,429 | #5,829 | 14,005 | 640BNDG leads by 600 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #3,758 | #3,338 | 14,005 | 640BNDG leads by 420 places | ## Questions ### Which panel is better: Ulica Solar TSM156-9-635BNDG or Ulica Solar TSM156-9-640BNDG? According to our database: **Ulica Solar TSM156-9-640BNDG** has higher module efficiency (**22.90%** vs **22.70%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Ulica Solar TSM156-9-635BNDG and Ulica Solar TSM156-9-640BNDG? **Ulica Solar TSM156-9-635BNDG** has a module efficiency of **22.70%**, while **Ulica Solar TSM156-9-640BNDG** is **22.90%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Ulica Solar TSM156-9-635BNDG use vs Ulica Solar TSM156-9-640BNDG? **Ulica Solar TSM156-9-635BNDG** uses **TOPCon** cells; **Ulica Solar TSM156-9-640BNDG** uses **TOPCon**. 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 Ulica Solar TSM156-9-635BNDG and Ulica Solar TSM156-9-640BNDG? **Ulica Solar TSM156-9-635BNDG** has a **30 years** power warranty; **Ulica Solar TSM156-9-640BNDG** 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 Ulica Solar TSM156-9-635BNDG and Ulica Solar TSM156-9-640BNDG bifacial panels? Both **Ulica Solar TSM156-9-635BNDG** and **Ulica Solar TSM156-9-640BNDG** 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 - [Ulica Solar TSM156-9-635BNDG vs Ulica Solar TSM156-9-645BNDG](https://comparepv.com/compare/ulica-solar-tsm156-9-635bndg/ulica-solar-tsm156-9-645bndg) - 3 differences, the largest is module efficiency - [Ulica Solar TSM156-9-635BNDG vs Ulica Solar TSM156-9-630BNDG](https://comparepv.com/compare/ulica-solar-tsm156-9-635bndg/ulica-solar-tsm156-9-630bndg) - One difference: module efficiency - [Ulica Solar TSM156-9-635BNDG vs Ulica Solar TSM156-9-625BNDG](https://comparepv.com/compare/ulica-solar-tsm156-9-635bndg/ulica-solar-tsm156-9-625bndg) - 3 differences, the largest is module efficiency - [Ulica Solar TSM156-9-635BNDG vs Ulica Solar TSM156-9-620BNDG](https://comparepv.com/compare/ulica-solar-tsm156-9-635bndg/ulica-solar-tsm156-9-620bndg) - 3 differences, the largest is module efficiency - [Ulica Solar TSM156-9-635BNDG vs Ulica Solar UL-715M-132DGN](https://comparepv.com/compare/ulica-solar-tsm156-9-635bndg/ulica-solar-ul-715m-132dgn) - 12 differences, the largest is rated power - [Ulica Solar TSM156-9-635BNDG vs Ulica Solar UL-710M-132DGN](https://comparepv.com/compare/ulica-solar-tsm156-9-635bndg/ulica-solar-ul-710m-132dgn) - 10 differences, the largest is rated power --- Source: https://comparepv.com/compare/ulica-solar-tsm156-9-635bndg/ulica-solar-tsm156-9-640bndg 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.