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Solar panels are an increasingly common sight on the roofs of homes and commercial premises across the UK – but have you ever stopped to wonder how they’re made? It might seem like a purely academic question; as long as they work, why does it matter how they’re put together?
But for homeowners and businesses concerned about ethical supply chains, understanding the manufacturing process, the materials used and the environmental impact of the various types of solar panels on the market can be a deciding factor when making the switch to solar PV.
What are solar panels made of?
A solar PV panel is a complex piece of engineering – not only in terms of the solar cells that convert sunlight into electrical energy, but also each of the structural and protective components that ensure durability, efficiency, and a long functional lifespan. As with any electronic device, the quality of the materials used and the manufacturing process have a significant effect on the quality of the finished panels, as well as the cost.
| Component | Material | Function |
| Photovoltaic (PV) cells | Silicon (monocrystalline or polycrystalline) | The core component that converts sunlight directly into DC electricity through the photovoltaic effect. |
| Front cover | Tempered glass (Low-iron) | Protects the PV cells from weather, impact, and debris while maximising sunlight transmission. |
| Frame | Anodised aluminium | Provides structural rigidity, protects the edges of the laminate, and allows for secure mounting. |
| Encapsulant | Ethylene Vinyl Acetate (EVA) | A polymer layer that bonds the cells to the glass and backsheet, providing cushioning and preventing moisture ingress. |
| Backsheet | Polymer composite (e.g., PVF, PET) | Acts as a moisture barrier and electrical insulator on the rear side of the panel. |
| Junction box | Plastic housing with diodes and connectors | An enclosure on the back of the panel where the electrical connections are made, ensuring a safe output of power. |
Types of solar panels and their materials
The material most commonly associated with solar panels is silicon – the key ingredient in the “magic trick” that turns sunlight into usable, storable energy. But not all solar panels use silicon in the same way. Differences in how the silicon is processed and applied result in different types of solar panels, which vary in performance, appearance, and cost.
Top performer: Monocrystalline
Monocrystalline solar panels are manufactured from a single, high-purity silicon crystal ingot. The uniform crystal structure results in a sleek, black appearance and the highest efficiency rates. They perform better in low-light conditions and high temperatures, but are typically the most expensive to produce due to the energy-intensive manufacturing process.
Cost-effective: Polycrystalline
Polycrystalline panels are made by melting multiple silicon fragments together and casting them into a square block. This process is faster and cheaper, but the boundaries between crystals give the cells a blue, marbled look and slightly lower efficiency. However, they are a popular choice where budget is a key factor.
Most flexible: Thin-Film
Thin-film panels are produced by depositing one or more thin layers of photovoltaic material (e.g. amorphous silicon, cadmium telluride, or CIGS) onto a flexible substrate. This makes them lightweight, and cheaper to produce, but results in lower efficiency and a shorter lifespan compared to mono- or polycrystalline panels. They are often used in large-scale solar farms or for unique applications where the flexibility of the panel is key.
A step-by-step guide: how solar panels are made
The manufacturing of a crystalline silicon solar panel is a multi-stage process that transforms raw sand into a sophisticated energy-generating device.
| Stage | Process |
| Silicon purification | Quartz sand is melted into 99% pure silicon, then chemically refined until only a few atoms in a million remain as impurities. The result—ultra-pure “polysilicon”—is the raw material for solar cells. |
| Ingot and wafer creation | Polysilicon is remelted and grown into a single round crystal or cast as a square block. Diamond wires then slice it into wafer-thin discs or squares, each about as thick as a sheet of card. |
| Doping and cell creation (P-N Junction) | Tiny amounts of boron are added into one side of each wafer, phosphorus into the other. This forms a positive (P) and a negative (N) layer. The boundary between them creates the electric field that turns light into usable current. |
| Anti-reflective coating & conductors | A blue-grey silicon-nitride film reduces reflections so the cell absorbs more sunlight. Fine silver lines are printed on the front and back, acting like miniature wires that gather and carry the generated electricity. |
| Cell connection and lamination | Dozens of cells are soldered into strings, laid between clear EVA plastic, toughened glass and a polymer backsheet, then heated under vacuum. The layers fuse into a single, weather-sealed laminate. |
| Framing and mounting | An anodised aluminium frame gives rigidity and fixing points. A junction box with built-in bypass diodes is glued to the rear, providing waterproof cable connections to the rest of the solar array. |
| Testing and quality control | Each finished panel is flashed with a burst of artificial sunlight to check power output, scanned for cracks, and electrically safety-tested before it leaves the factory. |
The environmental impact of solar panel manufacturing
While solar panels are a cornerstone of the transition to clean, renewable energy, manufacturing them at scale is not without environmental impact. However, the majority of this impact is offset – at least eventually – by the energy the panels generate over time, and by increasingly responsible sourcing, manufacturing and recycling practices.
Energy use
Producing solar panels is an energy-intensive process, particularly purifying silicon and growing crystals. However, when we look at the energy payback time (EPBT) – the length of time a panel must operate to generate the same amount of energy that was used to produce it – solar panels score well. Modern panels have an EPBT of around 1-4 years, compared to their 25-30 year operational lifetime.
Raw materials and waste
Cleaning and etching the wafers uses acids, solvents and large amounts of rinse water. More responsible manufacturers utilise closed-loop systems that capture, clean, and reuse both chemicals and water, resulting in very little hazardous waste.
Ethical sourcing and labour
Silicon, quartz and other raw materials pass through several countries before they reach the factory. Top brands now audit every step—mines, smelters, transportation, and assembly—to ensure that raw materials are conflict-free and that workers are paid fairly and working conditions are well-regulated.
Circularity and recycling
The industry is actively developing more efficient methods to recycle old panels. Modern recycling lines strip off the frame, shred the laminate, and separate out glass, aluminium, copper, and silicon for reuse. Better recovery rates mean new panels can be built partly from those being decommissioned.
Overall, the net environmental benefit of solar power is significant. During its 25-plus-year life, a single panel prevents several tonnes of CO₂ from entering the atmosphere—far outweighing the emissions from making it. As manufacturing becomes more efficient and recycling infrastructure improves, the overall sustainability of solar technology will only increase.
What makes a high-quality solar panel?
As we touched on in the materials section above, what a solar panel is made of, how it’s manufactured, and its overall build quality all impact performance, reliability, and longevity. Whether you’re pricing up panels for home use or considering a commercial solar panel installation, understanding these factors is crucial to maximising the value of your investment.
Material grade
The purity of the silicon used is a major factor affecting efficiency and output. The higher the grade of silicon used, the fewer defects or “dead cells” you’ll encounter, resulting in better efficiency and output from day one, and improved long-term performance.
Manufacturing standards
Reputable manufacturers adhere to strict international standards (like IEC certifications) and maintain tight tolerances throughout production, for a consistent and reliable end product. If you spot a cheap deal from an unknown brand that looks too good to be true, it often will be!
Degradation rate
High-quality panels (from reputable manufacturers) will be backed by strong warranties. Look for a low degradation rate, which guarantees the panel will still produce a high percentage of its original power at the theoretical end of its lifespan – usually 25 years as standard.
The future of solar panel technology
Solar panel manufacturing is becoming cleaner, more efficient, and more sustainable – with new materials and production processes delivering ever-higher efficiency and output ratings. Solar PV is also better integrated than ever before, giving you the option to pair your panels with efficient solar battery storage, manage generation and consumption with smart grid systems, and even monetise your investment by selling power back to the grid.
But as the technology continues to evolve, for buyers, the principles remain the same when evaluating a purchase – prioritising quality materials, reputable manufacturers and expert installers. At JLM Energy, we partner with leading manufacturers who share our commitment to quality and durability. By focusing on superior engineering and materials, we ensure our clients receive systems built to last. Learn more about how our solar PV systems are engineered to deliver maximum value and reliability.
