What is inside a solar panel?

A solar panel is a sheet of glass over silicon cells, sealed in plastic layers and held in an aluminum frame. The glass and the frame are most of it and the simplest parts to recover; the silver printed on the cells is much harder to reach. This page describes the common crystalline-silicon panel, and thin-film panels hold different materials.¹

Drawing of a representative crystalline-silicon solar panel, not a specific product, as a corner section lying on a bench with one corner taken apart in layers: the anodized aluminum frame with its corner key and drain holes, the tempered front glass, a clear encapsulant sheet, a square silicon cell printed with fine silver grid lines and crossed by flat tinned-copper ribbons that string it to the next cell and to a bus ribbon, the rear encapsulant and the polymer backsheet; behind it a second section lies face down to show the mounting slots in the frame and the junction box with its lid off, four copper terminals, three bypass diodes, the ribbon tails and two output cables with their connectors, beside a corner of a pallet of stacked panels with corner protectors and straps. — A corner of a representative crystalline-silicon solar panel, taken apart in layers from the frame and the front glass down to the backsheet. A second section lies face down behind it to show the junction box with its lid off.

Materials in solar panels

Main materials
Material	Where it sits
Aluminum	Frame round the glass
Silicon	The cells under the glass
Copper	Ribbons, bus bars and junction-box cable

Trace materials
Material	Where it sits
Silver	Fine contact lines printed on cells
Tin	Coating on the copper ribbons
Lead	Ribbon solder in some panels

What a solar panel of this kind most likely holds. Amounts are given in words, not weights, because content depends on the design.

How solar panels are recycled

Recycling a panel typically begins with removing the aluminum frame and the junction box with its cables.¹ The frame is remelted with other aluminum scrap, and the copper cable is processed like other insulated wire.²³ The glass is then separated from the silicon cells by thermal, mechanical or chemical means, and it can be recovered as glass.¹ Only after that can the cells be treated to separate the silicon and the metals on them: the silver of the printed contact lines, used there for its high electrical conductivity, and the tin and copper of the ribbons. Whether a recycler takes this last step depends on its process.¹⁴ The solder in some panels contains a little lead, so how a discarded panel is classed as waste depends on what it holds. There is no battery and no magnet in a panel.¹

More on each stream: steel and aluminum, precious metals.

Find them in the games and recycle them

Mine the warehousePallet of solar panels (receiving dock)
Sort the device wallSolar panels (batteries, boards and cable)
Discuss business equipment with ERIFor equipment an organization is retiring.

Sources

Solar panel recyclingUS EPA
Recycling is the primary energy efficiency technology for aluminum and steel manufacturingU.S. Energy Information Administration, Today in Energy (May 9, 2014), Article body, sections on steel (electric arc furnaces) and aluminum (secondary production)
Copper Recycling in the United States in 2004 (U.S. Geological Survey Circular 1196-X)U.S. Geological Survey, Page X23, paragraph on old scrap handling (wire chopping, fluidized bed, cable stripping); page X12, 'Wire goes through a chopping operation', with footnote 10
Mineral Commodity Summaries 2026: SilverUS Geological Survey (February 2026), Page 1, 'Domestic Production and Use' and 'Recycling' paragraphs

Reviewed November 14, 2026