Final answer:
Iceland is the country that meets its electricity demands and a substantial portion of its total energy needs through geothermal and hydropower, leveraging its unique geological position and abundant water resources.
Step-by-step explanation:
The country that effectively uses geothermal and hydropower to provide all of its electricity and covers 80% of its total energy needs is Iceland. Geothermally, Iceland is situated on a geological hot-spot, which allows it to produce a significant fraction of its electricity from geothermal sources. Specifically, about 30% of Iceland's electricity is derived from geothermal energy. Additionally, Iceland utilizes its abundant water resources to generate the majority of its electricity through hydropower. Due to its low population and unique geology, it's able to sustainably meet its energy requirements in this manner.
In a global context, geothermal energy contributes about 0.4% of the global energy budget, which is quite small compared to traditional energy sources. However, for Iceland, the combination of geothermal and hydropower is more than sufficient to supply its energy needs. Furthermore, as environmental concerns over non-renewable energy sources grow, the use of geothermal heating for residential purposes is becoming more prevalent, as seen in Iceland, where nine out of ten homes are powered by geothermal energy.