IEA PVPS: Recycling, Substitution Key for Solar's Critical
A new IEA PVPS report warns that solar PV growth will drive major demand for critical metals like silver, copper, and indium, but finds recycling and
Solar PV deployment will be a primary driver of global demand for critical minerals in the coming decades, according to a new report from the International Energy Agency's Photovoltaics Power Systems Programme (IEA PVPS). The study models material consumption across scenarios of 29 to 75 terawatts-peak of global solar capacity by 2050.
Dr. Malte Vogt of Delft University of Technology, a co-author, told PV Tech that while PV uses less material volume than fossil fuel systems, it requires different kinds. "For materials like silicon, indium, silver, copper or tin, we expect it to be a key demand factor," Vogt said.
Copper and Silver Demand Pressures
The report estimates copper demand for solar could reach 7 to 15 million tonnes by the mid-2040s, equivalent to 30-65% of current annual global production. It forecasts a potential supply gap of 10.5 to 11.5 million metric tonnes by 2035.
For silver, annual use in PV cells is expected to peak at 9,000 metric tonnes. Demand between 2025 and 2050 could consume 15-30% of current global reserves. Yansong Shen from the University of New South Wales warned in a May interview that at current production rates, the solar industry could exhaust global silver reserves within five years.
The industry is working to replace silver with more abundant copper in cell production. Scientists at Germany's Fraunhofer ISE claimed in April they reduced silver use in TOPCon cells tenfold, from 10-12 milligrams per watt-peak to 1.1. However, mainstream products still use significant amounts.
The Critical Role of Recycling
The IEA PVPS report identifies end-of-life PV plants as a important future source of materials. "One of the key findings of our report is that recycling of end-of-life PV could contribute about 30-45% of all silver required for PV till 2050," Vogt stated. He projected that by 2050, recycling volumes will be 50 to 80 times today's levels.
Shen also emphasized that expanded PV recycling is key to sustaining the industry's silver demand.
Indium Presents a Supply Challenge
The rare metal indium, used for its conductive and transparent properties in solar cells, presents a significant supply problem. Under all deployment scenarios, the report expects indium demand to outstrip global reserves by the mid-2040s.
The IEA PVPS states it will be "necessary" to replace indium in transparent conductive oxides to achieve terawatt-scale annual PV deployments. While mining outputs are hard to predict, the report shows the urgency of finding alternatives.
Policy and Manufacturing Implications
The global expansion of PV manufacturing must integrate material replacements and recycling to meet demand sustainably. The report advises that both within China-where supply currently outpaces demand-and in regions like the US, India, and the EU building new supply chains, policy should balance production incentives with material efficiency.
"Material efficiency improvements and material substitution strategies should be considered alongside incentives for domestic production and processing when designing policies to support PV deployment," the IEA PVPS recommended. The full report is available through the IEA PVPS.
