--- title: "Sunova TS-BBT78(640) vs Sunova TS-BGT78(640) - Solar Panel Comparison | ComparePV" description: "Compare Sunova TS-BBT78(640) vs Sunova TS-BGT78(640) side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/sunova-ts-bbt78-640/sunova-ts-bgt78-640" updated: 2026-09-11 --- # Sunova TS-BBT78(640) vs Sunova TS-BGT78(640) BBT78(640) leads on the differences that matter The largest is weight: 5.0 kg lighter. 16 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Sunova TS-BBT78(640)](https://comparepv.com/panel/sunova-ts-bbt78-640) | [Sunova TS-BGT78(640)](https://comparepv.com/panel/sunova-ts-bgt78-640) | | Manufacturer | Sunova | Sunova | | Power | 640 Wp | 640 Wp | | Efficiency | 22.90 % | 22.90 % | | Technology | N-type | N-type | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | BBT78(640) | BGT78(640) | Difference | | --- | --- | --- | --- | | Weight | 29.0 kg | 34.0 kg | -5.0 kg for BBT78(640) | | Weight per kWp | 45.3 kg/kWp | 53.1 kg/kWp | -7.8 kg/kWp for BBT78(640) | | Dimensions | 2465x1134x35 mm | 2464x1134x35 mm | 2465x1134x35 mm vs 2464x1134x35 mm | ## Every compared parameter | Parameter | BBT78(640) | BGT78(640) | | --- | --- | --- | | Rated power | 640 Wp | 640 Wp | | Module efficiency | 22.90 % | 22.90 % | | Power density | 229.0 Wp/m² | 229.0 Wp/m² | | Open-circuit voltage | 56.75 V | 56.75 V | | Voltage at max power | 48.18 V | 48.18 V | | Short-circuit current | 13.94 A | 13.94 A | | Current at max power | 13.28 A | 13.28 A | | Temperature coefficient | -0.290 %/°C | -0.290 %/°C | | Dimensions | 2465x1134x35 mm | 2464x1134x35 mm | | Module area | 2.795 m² | 2.794 m² | | Weight | 29.0 kg | 34.0 kg | | Weight per kWp | 45.3 kg/kWp | 53.1 kg/kWp | | Product warranty | 15 yrs | 15 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.40 %/yr | | Cell technology | N-type | N-type | | 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, BBT78(640):** 21,473 kWh - **Cumulative output, BGT78(640):** 21,473 kWh - **Gap:** No difference ## Output when hot | Condition | Cell temperature | BBT78(640) | BGT78(640) | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 640 W | 640 W | 100.0% of rated power | | Cool, bright day | 40 °C | 612 W | 612 W | 95.7% of rated power | | Typical summer roof | 55 °C | 584 W | 584 W | 91.3% of rated power | | Hot roof | 70 °C | 556 W | 556 W | 87.0% of rated power | ## Against the whole database | Measure | BBT78(640) | BGT78(640) | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #2,359 | #2,359 | 14,005 | Tied - the same position in the database | | Power density | #2,389 | #2,380 | 14,005 | BGT78(640) leads by 9 places | | Heat behaviour | #2,165 | #2,165 | 14,005 | Tied - the same position in the database | | Weight | #688 | #6,913 | 14,005 | BBT78(640) leads by 6,225 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #1,671 | #1,695 | 14,005 | BBT78(640) leads by 24 places | ## Questions ### Which panel is better: Sunova TS-BBT78(640) or Sunova TS-BGT78(640)? According to our database: both panels are closely matched on key specs - the decision often comes down to price and local availability. See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Sunova TS-BBT78(640) and Sunova TS-BGT78(640)? **Sunova TS-BBT78(640)** has a module efficiency of **22.90%**, while **Sunova TS-BGT78(640)** is **22.90%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Sunova TS-BBT78(640) use vs Sunova TS-BGT78(640)? **Sunova TS-BBT78(640)** uses **N-type** cells; **Sunova TS-BGT78(640)** uses **N-type**. 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 Sunova TS-BBT78(640) and Sunova TS-BGT78(640)? **Sunova TS-BBT78(640)** has a **30 years** power warranty; **Sunova TS-BGT78(640)** 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 Sunova TS-BBT78(640) and Sunova TS-BGT78(640) bifacial panels? Both **Sunova TS-BBT78(640)** and **Sunova TS-BGT78(640)** 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 - [Sunova TS-BBT78(640) vs Sunova TS-BBT78(635)](https://comparepv.com/compare/sunova-ts-bbt78-640/sunova-ts-bbt78-635) - One difference: module efficiency - [Sunova TS-BBT78(640) vs Sunova TS-BGT78(635)](https://comparepv.com/compare/sunova-ts-bbt78-640/sunova-ts-bgt78-635) - 4 differences, the largest is weight - [Sunova TS-BBT78(640) vs Sunova TS-BGT78(630)](https://comparepv.com/compare/sunova-ts-bbt78-640/sunova-ts-bgt78-630) - 6 differences, the largest is weight - [Sunova TS-BBT78(640) vs Sunova TS-BBT78(630)](https://comparepv.com/compare/sunova-ts-bbt78-640/sunova-ts-bbt78-630) - 3 differences, the largest is module efficiency - [Sunova TS-BBT78(640) vs Sunova TS-BBT78(625)](https://comparepv.com/compare/sunova-ts-bbt78-640/sunova-ts-bbt78-625) - 3 differences, the largest is module efficiency - [Sunova TS-BBT78(640) vs Sunova TS-BGT78(625)](https://comparepv.com/compare/sunova-ts-bbt78-640/sunova-ts-bgt78-625) - 6 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/sunova-ts-bbt78-640/sunova-ts-bgt78-640 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.