According to de Castro et al. [11], mineral reserves of some scarce materials being used will also put pressure on the PV industry, because there is also a trade-off between solar system efficiencies and mineral limits. Although it is very difficult to provide a global limit to the expansion of solar power, an overview of materials needed for large-scale implementation shows that many of the estimations found in the literature are hardly compatible with the rest of human activities. Overall, solar could be more limited than supposed from a technological and sustainable point of view.