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.