Will Solar Panels Work Through Glass?
Short answer: Yes, solar panels can work through glass, but the efficiency drops significantly. If you’re thinking about installing solar panels indoors or behind a window, there are a few important technical and practical factors to understand before moving ahead.
In this guide, we break down how solar panels interact with glass, when it might make sense, and when it doesn’t.
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How Solar Panels Generate Power
Solar panels work by absorbing sunlight, specifically photons, and converting them into electricity through a process called the photovoltaic effect. The more direct sunlight they receive, the more electricity they produce.
The surface angle, intensity of sunlight, and any barriers between the sun and the panel (like glass) all affect how well they perform.
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What Happens When You Put Glass Between the Sun and a Solar Panel?
Glass reflects, diffuses, and sometimes absorbs light. When solar panels are placed behind standard glass, several things happen:
- Reflection: A portion of sunlight bounces off the glass and never reaches the panel.
- Diffusion: Light is scattered and becomes less concentrated.
- Absorption: Some energy is absorbed by the glass itself.
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Together, these effects reduce the amount of usable light that reaches the panel, and therefore, reduce electricity output.
How Much Power Loss Can You Expect?
The reduction in performance depends on the type of glass and its thickness. Here’s a rough breakdown:
- Clear window glass: 30% to 50% loss
- Tinted or double-glazed windows: Up to 70% loss or more
- Low-iron or solar glass: 10% to 20% loss (used in solar-specific applications)
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Panels placed behind glass will still generate electricity, but nowhere near the output of a panel in direct sunlight.
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Can You Use Solar Panels Indoors?
Technically yes, but practically no. Most homes don’t receive enough concentrated sunlight indoors to make solar power generation viable.
Even in a sun-drenched room, the energy reaching the panel is too weak and inconsistent to generate useful amounts of power.
There are exceptions:
- Small solar panels powering indoor gadgets or sensors
- Specialised low-power indoor solar cells (like those on calculators)
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But for home electricity production? It’s not worth it.
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Are There Glass Products That Work with Solar Panels?
Yes. Some glass products are designed to work with solar systems:
- Solar glass / low-iron glass: Specially designed to allow maximum light penetration with minimal loss
- Building-integrated photovoltaics (BIPV): Glass with solar cells built-in, used in facades, windows, and skylights
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These are engineered for solar performance and are far more efficient than regular window glass.
What About Putting Solar Panels on Conservatories or Inside Greenhouses?
Still not ideal. While these spaces get more sunlight than a typical room, the glass still causes significant energy loss. If you’re aiming to power your home, panels need to go outside on a roof or open structure, not behind glass.
In greenhouses, some choose to install semi-transparent solar panels that allow light through while generating power. But these are specialist products, not standard domestic panels.
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Best Practice for Solar Panel Placement
If your goal is serious energy generation, solar panels should always be:
- Installed outdoors in direct sunlight
- Positioned at the correct angle to maximise sun exposure
- Free from shading by trees, buildings, or obstructions
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Panels behind glass are simply too inefficient to justify the cost unless you’re working with niche applications.
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Summary
Solar panels can work through glass, but the efficiency is heavily reduced due to reflection, diffusion, and absorption. Indoor solar setups are rarely viable for powering homes. If you’re serious about generating solar power, keep your panels outside and unobstructed.
For the best results, consult with a certified installer like Heatforce, who can assess your site and recommend the optimal layout.
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FAQs: Will Solar Panels Work Through Glass?
Yes, but at much lower efficiency. Most windows block or scatter sunlight, reducing the panel’s ability to convert light into electricity.
You can, but the results will be minimal. Indoor light, even sunlight through windows, is not strong enough to power standard home solar systems.
Low-iron solar glass or anti-reflective glass allows the most light through and is often used in commercial or BIPV applications.
Yes, but performance will be poor. Tinted or curved auto glass significantly reduces solar input.
Yes. Double glazing adds extra layers of glass and air, which increases light loss and reduces panel performance further.
