Three discrete energy leagues.

In the next century there will be three categories of countries based on available energy. In most cases these leagues will determine relative wealth and rate of progress of respective countries, and global relevance. If you are in League one, your country will be dirt poor and unable to escape its respective energy state. You will be a low wage slave/debtor nation dependent on endless developmental aid. If you are in league three your citizens will be affluent and will be evolving fast along transhumanist lines.

League One
Residual carbon-based fuels, a sparse amount of wood and coal that is allowed within global carbon markets. Some fracking of what’s left in the ground. Mostly growing wood and then burning it. A smattering of hydro, tidal and similar projects. Very limited economic capacity to boostrap large scale solar capture. No resources to collectively afford any variant of nuclear energy resources. Your country will be a colony or client state of a more powerful political entity. Barely several ten gigawattyear, if that.

League Two
Widespread solar and other sustainable energy resources. A smattering of proliferation-proof nuclear energy types, primarily Thorium. With considerable effort hundreds of gigawattyears.

League Three
Complete consolidation of solar resources, widespread thorium, potentially fusion reactors. The nation is part of an energy bloc or grid with interconnected DC transport of electrical power. This allows the country to evolve in to the development of Space Based Solar Power – and from then on the sky is the limit and energy growth become unconstrained and exponential – the more you invest, the more energy you get, the cheaper the energy becomes. Easily tens of terawattsyears.