Poor countries adopted basic cell phones years after they were introduced and when they got cheap enough for the populations of those companies to afford. They got cheap because the wealthier countries adopted them in massive numbers.
The same thing could happen for renewable energy. First the wealthier countries achieve high adoption rates of solar and wind power along with batteries. That is going to take several more years (Germany is leading the way, as is the American midwest with wind). Then the costs really start to drop and the poorer countries can take advantage of the more affordable technology.
I agree that sustainable energy systems with micro grids offer great promise of low costs and easier implementation that obviates the need for expensive long distance transmission lines.
