Can confirm, we get negative spot prices sometimes. In Australia they have negative spot prices during the daily solar panel peak.
In New Zealand we use geothermal, rather than nuclear for the base load electricity.
Our geothermal plants produce about 20% of our electricity.
You could build geothermal plants in most countries that have hot springs or volcanoes.
Yeah, they are going to keep building it, out to 35% of generation. The hydro that's already been built will last for ages.
About 3/4 of the geothermal has been built in the last 25 years. They built the new ones when they understood what they were doing properly.
The first trial plant was built in the 1950s.