Material Insights · Understanding the Material World

Copper and Solar photovoltaics

Solar plants use about 2.5 to 7 tonnes of copper per MW, mostly in cabling and earthing, and record silver prices in early 2026 pushed cell makers to start replacing silver contacts with copper, which could make copper a cell material as well.

Copper (commodity) and Solar photovoltaics (energy): 3 relationships.

How they are linked

1. Cables, earthing and inverters

Physical flow · Medium · Copper → Solar photovoltaics

Panels are wired together and to inverters with copper cable, plants need buried copper earthing, and the cells are linked by copper ribbons.

  • about 5.5 tons copper per MW of solar power systems, CDA estimate
  • about 2.4 to 7 t copper per MW across studied US systems (5,400 to 15,432 lb, 2011 study)
  • about 1% copper share of a crystalline silicon panel, in interconnectors (IEA)

Most of the copper sits in the plant rather than the panel: power and grounding cable between panels dominates, while inverters, transformers and disconnects add a relatively small share. The IEA found distributed rooftop systems need about 40% more copper than utility-scale plants.

Sources: Copper Development Association; BBF Associates for Copper Development Association; IEA

2. Copper replacing silver contacts

Substitution · Rising · Copper can replace silver in cell metallisation

Cells collect current through printed silver paste lines; copper conducts almost as well at a tiny fraction of the price, so plating or printing copper cuts cell cost once oxidation and reliability problems are solved.

  • 30% silver paste share of total solar cell cost, Heraeus, February 2026
  • about $5.22 to $17.65 US silver paste cost per 450 W module, early 2025 to early 2026
  • 17% photovoltaics' share of world silver demand (196 Moz), as reported in February 2026

Silver touched a record $121.64 an ounce in January 2026, and LONGi planned to begin mass production of cells metallised with base metals such as copper between April and June 2026. A full shift would add only a small amount of copper per module but would remove a large source of silver demand.

Sources: Reuters (via StreetInsider)

3. Solar growth lifts copper

Transition · Rising · Solar build-out → copper demand

Copper demand from solar rises with gigawatts installed and with the share of rooftop systems, which use more copper per kilowatt.

  • about 40% more copper in distributed systems than in utility-scale plants
  • about 14% renewable generation share of India's cable demand (ICA India, 2025)

The IEA notes that fast solar growth has raised demand for silicon, silver and copper together. Grid connections for new solar parks add further copper beyond the plant boundary.

Sources: IEA; International Copper Association India; IEA

For investors

Key learnings

  1. Copper in solar is mainly a cable and earthing story, about 2.4 to 7 t per MW, so cable makers are the main copper beneficiaries.
  2. High silver prices, with paste at about 30% of cell cost in February 2026, make copper metallisation a real cost lever for cell makers.
  3. A shift to copper contacts would barely move copper demand but could cut photovoltaics' 17% share of silver demand.

What to track

  • Silver to copper price ratio: A higher ratio speeds copper metallisation (Daily · LBMA, LME)
  • Copper-metallised cell output from leading makers: Shows whether substitution is moving into mass production (Quarterly · company results (LONGi, Aiko))
  • Solar installations by segment, rooftop versus utility: Rooftop growth raises copper per MW (Quarterly · national data and IEA)

For policymakers

Key learnings

  1. Solar targets imply cable and copper demand of a few thousand tonnes per GW, which should be planned alongside module supply.
  2. Rooftop programmes use about 40% more copper per unit of capacity than utility plants, which cable and copper supply plans should allow for.
  3. Domestic cell makers that adopt copper contacts can cut their exposure to volatile silver prices.

What to track

  • Solar capacity additions in India by segment: Copper and cable demand from solar targets (Monthly · MNRE)
  • Silver and copper import bills: Effect of metallisation choices on import dependence (Monthly · Ministry of Commerce trade data)

India

Renewable generation already accounts for about 14% of India's cable demand; copper metallisation would cut the silver needs of India's growing cell industry.

Sources

  1. Copper in renewable energy, Copper Development Association
  2. Market Study: Current and Projected Wind and Solar Renewable Electric Generating Capacity and Resulting Copper Demand, BBF Associates for Copper Development Association (2011)
  3. The Role of Critical Minerals in Clean Energy Transitions (revised March 2022), copy hosted by the Resolution Copper EIS library, IEA (2022)
  4. Solar industry accelerates shift from silver as costs soar, Reuters (via StreetInsider) (2026)
  5. Copper's Key Role in Cables, International Copper Association India (2025)
  6. Global Critical Minerals Outlook 2025 (extract, copy hosted by the University of Texas), IEA (2025)