[why_only_15]

Iceland is a tiny country with unusual amounts of energy. Not all renewable sources are the same -- hydropower is fairly reliable too, for example -- but Iceland is just not a useful example for the whole world. The largest geothermal plant in the world by far is in California, but it's a small portion of our total energy use so no one cares. https://en.wikipedia.org/wiki/The_Geysers

[warbaker]

You can locate an aluminum plant pretty much anywhere you want, as the energy required to make aluminum is large compared to the cost of mining/shipping bauxite. This solves the main problem with geothermal, which is that it's in random locations around the world that don't necessarily have many people living there.

Any place with significant volcanic activity (e.g. Hawaii) could probably do geothermal power if they wanted to.

[why_only_15]

Hawaii did do geothermal, but in fact it's so geothermically active their main geothermal plant went offline for a while because lava got shot up their boreholes https://en.wikipedia.org/wiki/Puna_Geothermal_Venture