--- title: "Will A Solar Panel Work Behind a Window?" description: "Discover how solar panels perform behind glass, the factors affecting their efficiency, and which technologies work best for low-power applications." type: article version: 1 version_id: "2e3d1d86-31ae-4642-a244-ded3ac643b37" generated_at: "2026-06-04T12:56:09.129Z" author: "Seth Hansen" date_published: "2026-04-08T14:52:00.000Z" date_modified: "2026-05-05T13:43:31.769Z" language: en reading_time: "13 min" word_count: 2509 keywords: ["Will A Solar Panel Work Behind a Window?", "Key Takeaways", "Final Thoughts"] url: "https://blog.powerfilmsolar.com/education/the-horizon-blog/2019/04/26/will-a-solar-panel-work-behind-glass" --- # Will A Solar Panel Work Behind a Window? > Discover how solar panels perform behind glass, the factors affecting their efficiency, and which technologies work best for low-power applications. ## Key Takeaways - Why Windows Reduce Solar Panel Performance - Do Solar Panels Work Through Windows? - When Solar Panels Can Work Behind a Window - When Solar Panels Should Not Be Installed Behind a Window - Are Amorphous Silicon Panels Better Than Other Solar Technologies Behind Windows? ## Contents - [Why Windows Reduce Solar Panel Performance](#why-windows-reduce-solar-panel-performance) - [Do Solar Panels Work Through Windows?](#do-solar-panels-work-through-windows) - [When Solar Panels Can Work Behind a Window](#when-solar-panels-can-work-behind-a-window) - [When Solar Panels Should Not Be Installed Behind a Window](#when-solar-panels-should-not-be-installed-behind-a-window) - [Are Amorphous Silicon Panels Better Than Other Solar Technologies Behind Windows?](#are-amorphous-silicon-panels-better-than-other-solar-technologies-behind-windows) - [Key Takeaways](#key-takeaways) - [Final Thoughts](#final-thoughts) - [FAQ: Solar Panels and Windows](#faq-solar-panels-and-windows) 5 min read # Will A Solar Panel Work Behind a Window? [Daniel Stieler, Phd](https://blog.powerfilmsolar.com/author/daniel-stieler-phd) : Updated on May 5, 2026 [Solar Education](https://blog.powerfilmsolar.com/tag/solar-education) Will A Solar Panel Work Behind a Window? 9:09 *Originally Published 4-26-2019* One of the most common questions we hear is whether solar panels can work through a window. The short answer is yes, but performance drops compared to direct outdoor exposure. How much power a panel produces depends on the type of glass, coatings, tint, and the solar technology used. In this blog post, we break down when solar behind a window works, when it does not, and which technologies perform best. Take this blog post with you! ## **Why Windows Reduce Solar Panel Performance** Solar panels generate power by converting sunlight into electrical energy. When that sunlight passes through a window, it changes before reaching the panel. The chart below shows how different types of window glass filter sunlight across wavelengths. Clear glass allows most visible light to pass through but still blocks part of the solar spectrum. Low-E glass further reduces transmission, especially in the infrared range. [](https://www.commercialwindows.org/lowe.php) [Figure 1: Different types of window glass filter sunlight differently, with Low-E coatings significantly reducing infrared transmission.](https://www.researchgate.net/figure/Spectral-transmittance-curves-for-glazing-with-three-different-types-of-lowemittance_fig1_317138390) Windows do not just reduce the amount of light. They also change the type of light that reaches the panel. This matters because many solar technologies rely heavily on infrared light to generate power. This concept is explored further in ["Solar Intensity: Looks Can Be Deceiving"](/education/the-horizon-blog/2017/12/29/solar-intensity-looks-can-be-deceiving), which compares visible brightness and usable solar energy. Crystalline silicon technologies capture a large portion of energy from wavelengths between 800 and 1200 nm. Low-E coatings reduce transmission in that range, leading to lower power output behind modern windows. Amorphous silicon behaves differently. - It collects energy primarily from the visible spectrum (400–700 nm). - These wavelengths pass through glass more easily. - This results in less performance loss behind windows. Light type is only part of the story. The angle of sunlight also plays a major role. [](https://www.commercialwindows.org/transmittance.php) [](https://www.commercialwindows.org/transmittance.php) [Figure 2: As the angle of sunlight increases, more light reflects off the window surface, reducing the amount of energy that reaches the solar panel.](https://www.researchgate.net/figure/a-Sunlight-transmitted-and-reflected-by-635mm-clear-glass-as-a-function-of-the-incident_fig2_341178580) In addition to spectral losses, reflection also reduces performance as the angle of sunlight changes. When sunlight hits a window directly, most of it passes through. As the angle increases, more light reflects off the surface instead of entering. - Transmission stays fairly stable up to about 60 degrees. - Beyond that, reflection increases quickly. - This reduces the usable light reaching the panel. Several factors contribute to reduced output: - **Spectral filtering:** Glass blocks key wavelengths used by solar panels. - **Low-E coatings:** Reflect infrared energy. - **Tinting and lamination:** Further limit light transmission. - **Reflection losses:** Light reflects away at steeper angles. ## **Do Solar Panels Work Through Windows?** Yes, solar panels can generate electricity through windows, but at a lower efficiency. Solar panels behind windows receive less usable sunlight, which reduces output. For high-power applications, this can be a problem. For a deeper look at how light intensity affects solar performance, see ["Solar Intensity: Looks Can Be Deceiving"](/education/the-horizon-blog/2017/12/29/solar-intensity-looks-can-be-deceiving). You can also explore ["Outdoor vs Indoor Solar: The Key Differences"](/outdoor-vs.-indoor-solar-panels-key-differences-use-cases-and-performance-considerations) to better understand how indoor environments affect solar output. ## **When Solar Panels Can Work Behind a Window** ### **Low-Power or Maintenance Charging** Solar panels behind windows work best when steady, low-level energy matters more than peak output. The chart below shows how an amorphous silicon panel performs behind a window compared to one mounted outside. *Figure 3: Solar output behind a window varies significantly by orientation, with north-facing installations relying almost entirely on low diffuse light. West-facing results are not shown due to building limitations, but performance is expected to be similar to east-facing results. Indoor/outdoor values represent the ratio of the current measured behind the window compared to the same panel in the same position outside.* Even in favorable conditions, output is much lower. - South-facing windows perform best but still fall short of outdoor output. - East-facing windows produce more power early, then drop quickly. - North-facing windows rely on diffuse light and produce very little. - The performance presented is the best case for a panel mounted flat against the inside of the glass. If there is a significant air gap between the panel and the glass or if the panel is at a different angle than the glass, reflection losses will increase. Performance varies widely by orientation. South-facing windows can approach outdoor output under ideal conditions, while east and north-facing windows often drop to 7%-15% of outdoor output. This makes it suitable for: - Maintaining battery charge. - Offsetting small loads. - Powering low-energy electronics. This is a strong fit for environments where sunlight is filtered, indirect, or inconsistent. ### **Vehicle Interiors** Solar panels are often placed behind windshields to maintain batteries or power small systems. ***Figure 4:*** *Solar panels placed behind vehicle glass can lose 30–40% of available light, with tinting causing even greater reductions.* The chart above compares a panel behind a vehicle window to one in direct sunlight. - Behind a window placement reduces available light by 30% to 40%. - Tinting further reduces performance. - Even a light tint can significantly reduce output. In extreme cases: - A panel under a tinted sunroof may receive only 5% to 8% of available light. Solar behind vehicle windows works best for: - Battery maintenance - Ventilation systems - Low-power electronics ### **Indoor or Semi-Enclosed Spaces** Rooms with large windows and steady sunlight can support small solar applications. These setups are not ideal for high-power systems, but they can work when energy needs are modest. ## **When Solar Panels Should Not Be Installed Behind a Window** Solar panels behind a window are not recommended when: - Full power output is required. - Windows have heavy tint or Low-E coatings. - Sunlight is inconsistent. - The application is critical. In these cases, outdoor installation delivers much better performance. ## **Are Amorphous Silicon Panels Better Than Other Solar Technologies Behind Windows?** In most cases, yes. Amorphous silicon panels perform better under filtered light. - They work well in low-light environments. - They handle diffuse light more effectively. - They lose less performance behind glass. This makes them a strong choice for solar applications behind windows, where other technologies struggle. ## **Key Takeaways** - Solar panels work behind windows, but the output is reduced. - Glass type and coatings have a major impact. - Performance drops further with angle and reflection. - Solar panels behind a window work best for low-power applications. - Amorphous silicon performs better than other technologies in these conditions. ## **Final Thoughts** If you plan to use solar behind a window, the details matter. If you’re comparing indoor and outdoor performance, ["Outdoor vs Indoor Solar: The Key Differences"](/outdoor-vs.-indoor-solar-panels-key-differences-use-cases-and-performance-considerations) breaks down what to expect in each environment. Window type, lighting conditions, and panel technology all affect performance. PowerFilm helps customers design solar solutions for real-world environments, including low-light and behind-window applications. Our team helps you select the right technology and avoid performance gaps early. [Contact our team to design a solar solution](https://share.hsforms.com/1zhhbExFdSdGId8695Jj8Pw18mxi) that performs reliably in real-world conditions. ## **FAQ: Solar Panels and Windows** **Do solar panels work indoors near a window?** Yes, but output is limited. Solar panels near a window rely on indirect, filtered light, which reduces their performance. They work best for low-power or maintenance charging, not high-energy use. **Do solar panels work through regular windows?**Yes. Solar panels work through clear windows, but they produce less power because the glass filters and reflects part of the sunlight. **Does tinted or Low-E window glass affect solar performance?**Yes. Tinting and Low-E coatings significantly reduce the amount of usable solar energy reaching a panel, often lowering output more than standard clear glass does. **Will solar panels work behind a windshield?**They can, but performance is limited. Windshields are designed to block UV and infrared light, reducing the usable energy available for solar charging. **Is solar behind a window suitable for high-power applications?**No. Solar behind a window is best for low-power or maintenance charging. Applications that require full output should use panels outdoors in direct sunlight. **Should I install a solar panel behind a window or outside?** If possible, install the panel outside. Direct sunlight provides much higher output and more consistent performance. Behind-window placement only makes sense for low-power or space-limited applications. Take this blog post with you!  - #### Robert Fredrick 11/7/2021, 9:44:34 PM I LIKE THE BOSCAM WIRELESS BACKUP CAMERA. MY ONLY OBJECTION IS STEALING THE SOLAR PANEL MOUNTED IN THE REAR BUMPER. I HAVE A JEEP PATRIOT. WILL THIS SOLAR PANEL CHARGE INSIDE THE REAR WINDOW. LIVE IN FLORIDA 6 MONTHS A YEAR. YOU RESPONSE WOULD BE APPRECIATED. THANKS. #### Seth Hansen 11/8/2021, 1:40:22 PM Robert, thanks so much for reaching out. You will collect some of the potential power through a window, but it will be significantly reduced. If you know what power is necessary to maintain the battery, we could put together a rough estimate on what size panel you would need. Please let me know if you have any additional questions! #### Robert Fredrick 11/8/2021, 3:26:36 PM THANKS FOR GETTING BACK. YOU CAN’T BE FROM FLORIDA, THEY NEVER GET BACK. I’M JUST TRYING TO THINK AHEAD. I LIKE THE IDEA OF SOLAR. DOES THE SOLAR PANEL CONNECT TO THE CAMERA WITH A WIRE? ALSO THE BACK OF THE CAR FACES WEST WHICH IS COMPLETE SUN AT LEAST 6 HOURS A DAY. PERHAPS A LARGER SIZE SOLAR PANEL WOULD WORK. THANKS AGAIN FOR YOUR TIME, PROBABLY BE PURCHASING YOUR BEST BACKUP CAMERA. #### Seth Hansen 11/8/2021, 4:33:20 PM Robert, Thanks so much for your comment. Unfortunately we don't make a backup camera. Powering something like that is most likely possible with solar, but unfortunately, we don't have a turn-key solution for you. Apologies! #### Bill Trammell 8/27/2023, 12:03:18 PM Found you and I have huge question! Just bought 23 camero coupe and would like to install an "inside" rear window solar battery charger/maintaner - I tried a cheap one and it dropped to 7 volts inside mounted. Please advise what to do about this (understand now a controller is advisable due to 12 volt battery possible damage). Welcome any suggestions (PS I have 12 inches wide by about 32 inches long) suitable rear monting surface directly below the rear window which is tinted. Bill Trammell #### Seth Hansen 8/28/2023, 2:27:32 PM Bill, thanks so much for reaching out. Unfortunately we don't have a solution that will work inside of the car. I'll reach out to you directly via email as well and maybe we can come up with a solution for the outside of the vehicle. #### R Blackburn 9/19/2023, 2:01:42 AM I have two Jackery 200w mono-crystalline silicon panels.is there a way to mitigate or amplify light energy coming thru a double-glazed window? can I get any useful charge? I don't care if it takes a lot longer to charge, just that it DOES charge and meets the minimum operational standards. and does not damage the unit. #### Seth Hansen 9/20/2023, 1:39:19 PM Thanks so much for your comment! The best way to enhance charging is to place the panels as close to the window as possible. As long as there is nothing shading part of the panels and they are relatively uniformly illuminated, they will charge slower and should not damage anything. We don't have experience with this system, so please monitor performance carefully. It is also worth reaching out to the customer support folks at Jackery. Please let me know if you have any additional questions. I am happy to assist you. #### Brian Zahnstecher 10/3/2023, 5:09:07 PM Seth: Great blog topic and overview. It is one thing to answer the simple question about major differences between indoor/output PV, but it is another to comprehensively go through the details of things like transmittance based on window medium and incident/azimuth angle...great stuff, thanks again! Regards, Brian #### Seth Hansen 10/3/2023, 5:25:13 PM Brian, Thanks so much for your comment. It's much appreciated! As always, feel free to let me know if you need anything. #### Jim 12/25/2023, 6:41:28 PM Thank you Seth and powerfilmsolar! This is wonderful information! I appreciate the specificity of the graphs and charts. My interest is in the net effect when taking into account both 1) amount of light collected behind glass and 2) the efficiency in converting light collected into current. I would very much appreciate your comments on my assumptions and reasoning . Assumptions: 1)Thanks the very specific information in this article, compared to amorphous silicone CIGS, perovskites, polycrystalline silicon, and monocrystalline silicon lose about 50% of the light they can collect behind glass since wavelengths between 800-1200nm are blocked (rougly speaking). Advantage amorphous silicon. 2)But, amorphous silicon is less efficient in converting the light into current in the first place. Advantage CIGS, perovskites, polycrystalline silicon, and monocrystalline silicon Reasoning: Ignoring transmittance/reflectance loss, to roughly calculate the net effect of mounting a solar panel behind a window I would do the following: Amorphous: no loss from 400-700nm times 6-10% efficiency converting light to current = 6%-10% net efficiency behind glass Polycrystalling: 50% loss (per your article) times 15%-18% efficiency = 7.5%-9% net efficiency Monocrystalline: 50% loss times 16.5%-22% efficiency = 8%-11% net efficiency Conclusion - amorphous silicone could have a worse low end net efficiency (6% versus 7.5% and 8%), but the upper end is about the same (10% versus 9% and 11%). (I don’t know efficiency estimates for CIGS and perovskites). Sorry for the wordiness. #### Seth Hansen 1/2/2024, 4:25:05 PM Jim, Thanks so much for your comment. I am checking with my team and connect with you shortly via email. #### daslteam 2/10/2026, 7:49:22 PM This topic seems interesting for my use case. #### Seth Hansen 2/12/2026, 3:42:14 PM Thanks so much for your comment. I've reached out via email and look forward to connecting with you! [](https://blog.powerfilmsolar.com/outdoor-vs.-indoor-solar-panels-key-differences-use-cases-and-performance-considerations) #### [Outdoor vs. Indoor Solar Panels: Key Differences, Use Cases, and Performance Considerations](https://blog.powerfilmsolar.com/outdoor-vs.-indoor-solar-panels-key-differences-use-cases-and-performance-considerations) [Seth Hansen](https://blog.powerfilmsolar.com/author/seth-hansen) : January 26, 2026 [Internet of Things](https://blog.powerfilmsolar.com/tag/internet-of-things) [Solar Education](https://blog.powerfilmsolar.com/tag/solar-education) [Read More](https://blog.powerfilmsolar.com/outdoor-vs.-indoor-solar-panels-key-differences-use-cases-and-performance-considerations) [](https://blog.powerfilmsolar.com/solar-cell-efficiency-explained-how-its-measured-and-why-it-matters) #### [Solar Cell Efficiency Explained: How It’s Measured and Why It Matters](https://blog.powerfilmsolar.com/solar-cell-efficiency-explained-how-its-measured-and-why-it-matters) [Daniel Stieler, Phd](https://blog.powerfilmsolar.com/author/daniel-stieler-phd) : March 10, 2025 [Solar Education](https://blog.powerfilmsolar.com/tag/solar-education) [Read More](https://blog.powerfilmsolar.com/solar-cell-efficiency-explained-how-its-measured-and-why-it-matters) [](https://blog.powerfilmsolar.com/education/the-horizon-blog/2019/03/05/comparing-portable-solar-technologies) #### [Which Portable Solar Technology Is Best: A Primer](https://blog.powerfilmsolar.com/education/the-horizon-blog/2019/03/05/comparing-portable-solar-technologies) [Seth Hansen](https://blog.powerfilmsolar.com/author/seth-hansen) : January 9, 2024 [Solar Education](https://blog.powerfilmsolar.com/tag/solar-education) [Read More](https://blog.powerfilmsolar.com/education/the-horizon-blog/2019/03/05/comparing-portable-solar-technologies) --- ## Frequently Asked Questions ### Do Solar Panels Work Through Windows? Yes, solar panels can generate electricity through windows, but at a lower efficiency. Solar panels behind windows receive less usable sunlight, which reduces output. For high-power applications, this can be a problem. For a deeper look at how light intensity affects solar performance, see "Solar Intensity: Looks Can Be Deceiving". You can also explore "Outdoor vs Indoor Solar: The Key Differences" to better understand how indoor environments affect solar output. ### Are Amorphous Silicon Panels Better Than Other Solar Technologies Behind Windows? Amorphous silicon panels perform better under filtered light. This makes them a strong choice for solar applications behind windows, where other technologies struggle. --- ## About This Content **Source:** [Will A Solar Panel Work Behind a Window?](https://blog.powerfilmsolar.com/education/the-horizon-blog/2019/04/26/will-a-solar-panel-work-behind-glass) **Author:** Seth Hansen **Published:** April 8, 2026 *This content is provided for informational purposes. Please visit the original source for the most up-to-date information.*