Geothermal energy is one of the lowest-cost energy sources available. It has huge potential for lowering greenhouse gas emissions and saving money. Despite this, harnessing heat from the Earth almost doesn’t happen outside Iceland. That isn’t very resourceful considering that 90 countries possess proven geothermal resources with the potential to be harnessed. However, Italy recently opened its first-ever geothermal energy production plant, and with political leaders 25 countries discussing the topic in Florence this week, more countries may follow suit.