Well the question was "Iceland has profitable geothermal, no?" and your answer appears to be yes. Which is important because it means the upshot is that there are viable applications, which contrasts against the argument that lack of generalized solution means we need to reject it wholesale.
You're right that that nuance got lost and I'm sorry I overlooked it.
Insofar as it relates to the commenter I'm replying to, they also seem not to be making a distinction about deep geothermal, but insisting that the difference between Iceland and the rest of the globe is an indictment of geothermal's viability deep or otherwise. Which doesn't follow.
The original comment stated that shallow geothermal can be useful for heating, but did not say anything about shallow geothermal electricity generation.
See the first paragraph. [0] The reference explicitly gets into "deep geothermal" (i.e., EGS) and talks about power applications that are viable because of limited drilling (i.e., shallow).
> The more than 1 gigawatt of geothermal power currently produced globally — from California to Iceland to the Philippines — relies nearly exclusively on such natural outpourings of the earth’s heat.
The building heat comment is just a reference to another residential/C&I application with ground loops. They're not dismissing or not acknowledging the grid-scale power applications.
"Shallow geothermal for building heat works fine, but it takes a lot of drilling just to get some heat."
From my understanding, this is all the original comment says about shallow geothermal. Correct me if I am misunderstanding.
Moreover, I do not see the quote: "The more than 1 gigawatt of geothermal power currently produced globally — from California to Iceland to the Philippines — relies nearly exclusively on such natural outpourings of the earth’s heat" anywhere.
Are we referring to the same comment, or am I misunderstanding something?
Iceland is one of several geothermal "high temperature zones", other zones include effectively the entire West Coast of all of North and South America, including Alaska, as well as a zone stretching from the Mediterranean through the Red Sea that encompasses basically every European country with Mediterranean coastline. There's a major zone stretching from India through Southeast Asia and a separate independent one basically going along the whole western perimeter of the Pacific Ocean.
Geothermal is currently deployed in 32 countries and is regarded as the most abundant source of renewable energy outside of solar, impressively ranking ahead of wind.
So I think the most charitable interpretation of Iceland's example is that it represents one of many regions where geothermal is viable.
