Modern solar panels are made up of several layers, each with its own purpose. Combined, they create panels that can generate clean energy to power your home while standing up to decades of wind, weather, and debris.
We created this guide to help you understand the different materials and components that are used in solar panel technology. You’ll also learn what choices you have when it comes to solar technology, and the distinct features of each one.
PowerOutage.us tracks 950+ utilities across 96% of the U.S., delivering real-time outage alerts by text and email the moment your power goes down. Knowing how solar panels are constructed can help you figure out whether your system can actually keep you powered through those outages.
What are solar panels made of?
Home solar panels are made of several key materials that work together to convert sunlight into electricity. A solar panel contains silicon cells, which act as the main semiconductors. These cells are protected by a layer of tempered glass. Metal frames, usually aluminum, hold everything together. Wires connect the cells, while a plastic or polymer backing insulates and protects the panel.
Here’s a detailed overview of the different solar panel components:
| Component | Definition | Main purpose |
|---|---|---|
| Silicon Wafers | Thin slices of crystalline silicon that convert sunlight into electricity | Core PV material |
| Glass Layer | Tempered glass that protects the panel and lets light pass through | Structural protection |
| EVA (Encapsulant) | Transparent material that bonds and protects solar cells from moisture and UV | Encapsulation material |
| Backsheet | Rear layer that protects internal components and insulates electrically | Structural layer |
| Frame | Aluminum border that provides structural support and allows for mounting | Mechanical support |
| Solder and Busbars | Conductive materials connecting cells for electric current flow | Electrical conduction |
| Anti-Reflective Coating | Reduces light reflection to increase absorption | Efficiency enhancer |
| Junction Box | Housing for wiring and bypass diodes, located on the back of the panel | Electrical interface |
| Photovoltaic Cell | The active part of the panel that converts light into electricity | Energy generation component |
| TPT Backsheet | Common composite backsheet made for durability and weather resistance | Backsheet material |
| Adhesive Sealant | Bonds panel layers and seals against water and air intrusion | Assembly component |
| PERC Layer | Backside layer that improves electron reflection and cell efficiency | Cell design innovation |
Next, we’ll cover a few main components in detail.
Photovoltaic (PV) cell layer
The PV cell layer is where solar panels generate electricity. Photovoltaic cells use silicon as their primary conductor, capturing sunlight and converting it to electricity through the photovoltaic effect.
Pure silicon conducts electricity but doesn't create a strong electric field on its own. Manufacturers dope the silicon with trace amounts of other elements to fix this. One layer gets doped with boron to create a p-type semiconductor with extra holes (positive charge carriers). The other gets doped with phosphorus to create an n-type semiconductor with extra electrons. When sunlight excites those electrons, they move across the p-n junction and generate an electric current.
Protective layers
Solar panels use protective layers on both sides of the PV cell layer:
- Tempered glass (top layer): Strong tempered glass covers the sun-facing side. It resists scuffs and cracks while letting light pass through to the PV layer.
- Ethyl vinyl acetate (EVA) encapsulant: A thin adhesive film bonds the PV layer to the surrounding layers. It's also UV-resistant, which helps extend the life of the PV layer.
- Backsheet: Most solar panels are monofacial, capturing light from one side only. On those panels, the backsheet behind the PV layer is opaque and typically metal. On bifacial panels, the backsheet is transparent, usually the same tempered glass used on the front.
Frame and mounting hardware
The layered panel assembly sits on an aluminum frame that angles it toward the sun and holds it to a roof or other surface. That full mounting system is called solar racking.
Junction box
A plastic junction box protects the panel's electrical connections from water, dirt, and other hazards.
Types of solar cells and their differences
There are several types of solar panels, and each one uses a different kind of solar cell. The differences pretty much come down to efficiency, durability, and cost.
Monocrystalline silicon solar cells
Monocrystalline cells are cut from a single piece of silicon. That gives them higher efficiency and better durability than other cell types. They cost more, but they're the most widely used cell type in residential solar installations in the U.S.
Polycrystalline silicon solar cells
Polycrystalline cells are made by fusing smaller pieces of silicon together. They're less efficient than monocrystalline cells. National Laboratory of the Rockies (NLR) research puts the median annual degradation rate for solar panels at 0.5% per year, and rooftop systems in hot climates tend to degrade faster because of reduced airflow and higher operating temperatures. Polycrystalline cells cost less and take fewer resources to produce, but that faster degradation compounds over a 20-plus-year system life.
Amorphous silicon solar cells
Also called thin-film solar technology, amorphous silicon (a-Si) cells press a non-crystalline form of silicon onto glass, metal, or plastic. They're lighter and more flexible than crystalline cells but less efficient. That tradeoff makes them a good fit for portable solar devices and smaller applications.
How solar panels work step by step
The photovoltaic effect is actually pretty straightforward. Here's how electricity moves from sunlight to your outlets:
- Sunlight passes through the tempered glass and EVA layers and reaches the PV cell layer.
- The silicon cells absorb photons, exciting electrons in the doped silicon layers.
- The p-type layer (boron-doped) and the n-type layer (phosphorus-doped) form an electric field at the p-n junction. That field pushes excited electrons toward the n-type side, producing direct current (DC) electricity.
- Metal fingers collect the electrons and route them to conductive strips called busbars.
- Busbars carry the DC electricity to a solar inverter.
- The inverter, housed in a protected junction box, converts DC electricity to alternating current (AC) that powers your home.
Bottom line on solar panel construction
Each layer in a solar panel has a specific job: generate electricity, protect the cell, or hold the assembly in place. The panel type you choose affects efficiency, lifespan, and cost. NLR has documented that well-built PV modules have demonstrated 30 years of outdoor performance, and 25-year warranties are now standard. So those differences compound over a long time horizon. And that's worth keeping in mind when you're sizing a system to carry your home through a power outage.
If you analyze the cost and decide solar isn’t worth it, that’s OK, too. Not all homes, energy markets, or climates are the best for solar panels.
