I live in an archipelago of volcanic islands and asked the same from an enginner working in the power company. According to him, geothermal is only viable above

I live in an archipelago of volcanic islands and asked the same from an enginner working in the power company. According to him, geothermal is only viable above a certain amount of power which restricts it to the largest islands. For the smaller islands (up to 15 thousand inhabitants) a combination of solar, wind and diesel is used instead.