--- title: "First Solar FS-7515A-TR1 vs First Solar FS-7535A-TR1 - Solar Panel Comparison | ComparePV" description: "Compare First Solar FS-7515A-TR1 vs First Solar FS-7535A-TR1 side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/first-solar-fs-7515a-tr1/first-solar-fs-7535a-tr1" image: "https://comparepv.com/og/compare/panels/first-solar-fs-7515a-tr1/first-solar-fs-7535a-tr1.png" updated: 2026-09-11 --- # First Solar FS-7515A-TR1 vs First Solar FS-7535A-TR1 7535A-TR1 leads on the differences that matter The largest is module efficiency: 0.70 pp more efficient. 12 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [First Solar FS-7515A-TR1](https://comparepv.com/panel/first-solar-fs-7515a-tr1) | [First Solar FS-7535A-TR1](https://comparepv.com/panel/first-solar-fs-7535a-tr1) | | Manufacturer | First Solar | First Solar | | Power | 515 Wp | 535 Wp | | Efficiency | 18.40 % | 19.10 % | | Technology | CdTe | CdTe | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 7515A-TR1 | 7535A-TR1 | Difference | | --- | --- | --- | --- | | Module efficiency | 18.40 % | 19.10 % | +0.70 pp for 7535A-TR1 | | Power density | 184.1 Wp/m² | 191.3 Wp/m² | +7.2 Wp/m² for 7535A-TR1 | | Rated power | 515 Wp | 535 Wp | +20 W for 7535A-TR1 | | Open-circuit voltage | 225.00 V | 227.20 V | 2.20 V apart | | Weight per kWp | 77.1 kg/kWp | 74.2 kg/kWp | -2.9 kg/kWp for 7535A-TR1 | | Voltage at max power | 184.30 V | 187.80 V | 3.50 V apart | ## Every compared parameter | Parameter | 7515A-TR1 | 7535A-TR1 | | --- | --- | --- | | Rated power | 515 Wp | 535 Wp | | Module efficiency | 18.40 % | 19.10 % | | Power density | 184.1 Wp/m² | 191.3 Wp/m² | | Open-circuit voltage | 225.00 V | 227.20 V | | Voltage at max power | 184.30 V | 187.80 V | | Short-circuit current | 3.03 A | 3.06 A | | Current at max power | 2.80 A | 2.85 A | | Temperature coefficient | -0.320 %/°C | -0.320 %/°C | | Dimensions | 2300x1216x49 mm | 2300x1216x49 mm | | Module area | 2.797 m² | 2.797 m² | | Weight | 39.7 kg | 39.7 kg | | Weight per kWp | 77.1 kg/kWp | 74.2 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.30 %/yr | 0.30 %/yr | | Cell technology | CdTe | CdTe | | Cell type | Thin film | Thin film | | Cell count | - | - | | 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 (-0.320 %/°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, 7515A-TR1:** 17,363 kWh - **Cumulative output, 7535A-TR1:** 18,037 kWh - **Gap:** 674 kWh ## Output when hot | Condition | Cell temperature | 7515A-TR1 | 7535A-TR1 | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 515 W | 535 W | 100.0% of rated power | | Cool, bright day | 40 °C | 490 W | 509 W | 95.2% of rated power | | Typical summer roof | 55 °C | 466 W | 484 W | 90.4% of rated power | | Hot roof | 70 °C | 441 W | 458 W | 85.6% of rated power | ## Against the whole database | Measure | 7515A-TR1 | 7535A-TR1 | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #13,225 | #12,993 | 14,129 | 7535A-TR1 leads by 232 places | | Power density | #13,207 | #12,973 | 14,129 | 7535A-TR1 leads by 234 places | | Heat behaviour | #8,376 | #8,376 | 14,129 | Tied - the same position in the database | | Weight | #13,791 | #13,707 | 14,129 | 7535A-TR1 leads by 84 places | | Warranty | #21 | #21 | 14,129 | Tied - the same position in the database | | Overall | #11,035 | #10,106 | 14,129 | 7535A-TR1 leads by 929 places | ## Questions ### Which panel is better: First Solar FS-7515A-TR1 or First Solar FS-7535A-TR1? According to our database: **First Solar FS-7535A-TR1** has higher module efficiency (**19.10%** vs **18.40%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of First Solar FS-7515A-TR1 and First Solar FS-7535A-TR1? **First Solar FS-7515A-TR1** has a module efficiency of **18.40%**, while **First Solar FS-7535A-TR1** is **19.10%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does First Solar FS-7515A-TR1 use vs First Solar FS-7535A-TR1? **First Solar FS-7515A-TR1** uses CdTe cells; **First Solar FS-7535A-TR1** uses CdTe. 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 First Solar FS-7515A-TR1 and First Solar FS-7535A-TR1? **First Solar FS-7515A-TR1** has a **30 years** power warranty; **First Solar FS-7535A-TR1** 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. ## Related comparisons - [First Solar FS-7515A-TR1 vs First Solar FS-7550A-TR1](https://comparepv.com/compare/first-solar-fs-7515a-tr1/first-solar-fs-7550a-tr1) - 6 differences, the largest is module efficiency - [First Solar FS-7515A-TR1 vs First Solar FS-7545A-TR1](https://comparepv.com/compare/first-solar-fs-7515a-tr1/first-solar-fs-7545a-tr1) - 6 differences, the largest is module efficiency - [First Solar FS-7515A-TR1 vs First Solar FS-7540A-TR1](https://comparepv.com/compare/first-solar-fs-7515a-tr1/first-solar-fs-7540a-tr1) - 6 differences, the largest is module efficiency - [First Solar FS-7515A-TR1 vs First Solar FS-7530A-TR1](https://comparepv.com/compare/first-solar-fs-7515a-tr1/first-solar-fs-7530a-tr1) - 6 differences, the largest is module efficiency - [First Solar FS-7515A-TR1 vs First Solar FS-7525A-TR1](https://comparepv.com/compare/first-solar-fs-7515a-tr1/first-solar-fs-7525a-tr1) - 5 differences, the largest is module efficiency - [First Solar FS-7515A-TR1 vs First Solar FS-7520A-TR1](https://comparepv.com/compare/first-solar-fs-7515a-tr1/first-solar-fs-7520a-tr1) - One difference: module efficiency --- Source: https://comparepv.com/compare/first-solar-fs-7515a-tr1/first-solar-fs-7535a-tr1 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.