2300AD energy sources

[Lemnoc]

A very interesting discussion, although I suspect that it is likely to miss the point in most cases of colony worlds. The presence of fossil fuels on a planet requires a rather specific development of the planet's biosphere and geology, and I therefore doubt very much that natural gas, oil or coal can be found at all or in significant quantities on many of the colony worlds.

It's all speculation, of course, but if organic life exists in any form on a planet, then it is likely to exist in earlier forms and in fossilized states. Petroleum, gas, coal... methane... would be among those states. Does a planet have tectonics? Those with described volcanoes and earthquakes probably do. Thus you have the potential at least for pressure and geologic time to do its work. All the ingredients.