Terawatt-Scale Photovoltaics Enabled by Technological Learning

Cost efficient climate change mitigation requires installing up to 170 TWp photovoltaic (PV) electricity production capacity until the year 2100. The question is, whether and how such growth is possible from a resource perspective. We have assessed the resource demand of such multi-TW-scale PV. Given the long time scale of our analysis, we did not focus on any specific technology. Instead, we looked at the fundamental resources energy, float-glass, and capital investments that will be necessary independently from which PV technology will dominate in the future. In our analysis, we considered via a learning rate approach that PV technology is continuously improving. Conversion efficiency is increasing, while cost, and energy consumption during production are continuously decreasing. We found that without further technological learning, serious resource constraints will limit the growth of PV industry. On the other hand, continued technological learning at current rates would enable rapid growth within reasonable boundaries of resource demand. With such technological learning, energy demand for production will correspond to 2-5% of global energy consumption leading to cumulative greenhouse gas emissions of 4–11% of the 1.5°C emission budget. Glass demand will exceed current float-glass production, requiring rapid capacity expansion. Installations costs would be in the range of 300–600 billion $US2020 per year. Technological solutions enabling such learning are foreseeable. Especially perovskite-based tandem solar cells promise to reach efficiencies, energy, and costs targets that allow for staying on the development paths obtained from extrapolating current learning rates. The specific material demands, however, of such technologies need to be analyzed carefully and the development steered towards using abundant and non-toxic materials to reach real sustainability.