Natural resource limitations to terawatt-scale solar cells

The predicted energy demand will reach 28 TW by 2050 and 46 TW by 2100. The deployment of solar cells as a source of electricity will have to expand to a scale of tens of peak terawatts in order to become a noticeable source of energy in the future. Of the current commercial and developmental solar cell technologies, the majority have natural resource limitations that prevent them from reaching a terawatt scale. These limitations include high energy input for crystalline-Si cells, limited material production for GaAs cells, and material scarcity for CdTe, CIGS, dye-sensitized, crystalline-Si, and thin-film Si cells. In this paper, we examine these limitations under the best scenarios for CdTe, CIGS, GaAs, dye-sensitized, and crystalline-Si solar cells. Without significant technological breakthroughs, these technologies combined would meet only a few percentage points (∼2%) of our energy demand in 2100.

Graphical AbstractThe estimated, best-scenario peak wattage for various solar cell technologiesSolar cell technologyEfficiency (%)Limiting materialReserve base (metric ton)Maximum wattageAveraged output (GW)% of 2100 energy demandCdTe10.6Tellurium48,000816 GWp120–1600.4CIGS11.5Indium16,000650 GWp100–1300.3Dye-sensitized7Ruthenium5,000890 GWp135–1800.4Crystalline-Si15Silver400,0005.7 TWp860–1,1502.5Full-size tableTable optionsView in workspaceDownload as CSVHighlights
► Material scarcity prevents most current solar cell technologies from reaching terawatt scales.
► Maximum power from current commercial solar cells would be limited to 1–2% of the 2100 energy demand.
► Annual production of current commercial solar cells would be limited to 100–200 GWp/year.
► Scarce materials in solar cells include indium, gallium, tellurium, ruthenium, and silver.