Idea of Geothermal Icon
The geothermal icon is represented with a building, but one part of the building will have higher top where smoke will come out of. The other part of the icon is there will be arrows coming from the bottom of the building or the ground and into the building.
This Geothermal icon is made in Material Design style
developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 6,100 icons, all in the same style and quality.