The non-rich countries would only be consumers/importers to start with. Natural gas and coal is cheaper so they'll transition later. But that's moot since all t

The non-rich countries would only be consumers/importers to start with. Natural gas and coal is cheaper so they'll transition later. But that's moot since all that's needed is for rich, stable democracies to build it out amongst themselves, there's enough diversity of sunlight and wind between them to get above 90% with no storage. You can even easily go above 70% in many countries with no storage and no international network, just purely domestic sources. The international network is just a cherry on top which reduces the need to overbuild by too much. But it's largely doable without. The nice thing that people forget is that wind and solar are negatively correlated, so the variability is self-cancelling within a country.