Perhaps this is a very dumb question, but how have people around the world living on smaller islands gotten their electricity in recent decades? Are they connected to the mainland's electrical grid, do they run their central own central power generator, or do individuals just use gas/solar power if they need electricity? I don't know about other nations with many islands, but in Greece's case, there are loads of small islands ranging from just a few people to hundreds to tens of thousands, so it probably makes a centralized infrastructure very hard.