content: Another interesting possibility is lengthy ultra high voltage direct current lines. Using HVDC you can transmit electricity with about a 3.5% loss per 1000km. The circumference of the Earth is 20,000km. That means it's possibly to get from literally one side of the planet to the other with a 35% energy loss - a figure that can likely be brought much lower as well. It seems like it'd be politically impossible for countries to work together in this way, yet the internet is a strong example to the contrary there even if there would be substantially greater technological challenges in this case.