In a paper published in Nature Energy Professor Aleh Cherp and co-authors analyse wind and solar power in the 60 largest countries. They show that in every country the growth of renewable electricity initially accelerates, then stabilises and eventually slows down. With help of mathematical models, they estimate the maximum growth rates achieved along these "S-curves". While maximum growth differs from one country to another, only in leading countries, like Germany, does it approach the speed that we would need in the world as a whole to reach climate targets.
Furthermore, the research shows, that developing countries which introduce wind and solar power later do not develop them faster, probably because of adverse socio-economic and political circumstances. This makes it especially difficult to replicate or exceed the growth rates from the national leaders to the continental or global scale. Overall, the paper articulates the enormous scale of the challenge of replacing traditional energy sources with renewables and the need to explore diverse climate solutions and scenarios.
Read the paper (link to Nature Energy)