It explores sources of geothermal energy, from volcanic heat just under the surface of the Earth to radioactive heat five kilometres below. Hot springs are used to generate electricity and heat buildings in Iceland and Tuscany, where one-tenth of the world’s geothermal energy is produced. Harvesting deep geothermal energy is more complex, however. The video illustrates how Norway’s thermal power plants work and how they hope to use technology developed for offshore oil drilling to overcome some of the challenges of extracting deep thermal energy.
The Earth’s geothermal energy originates from the original formation of the planet (20%) and from the radioactive decay of minerals (80%). Extremely high temperature and pressure cause some rock to melt, forming magma which, being lighter than the solid rock, convects upward. This magma heats rock and water in the crust, sometimes up to 700 degrees Fahrenheit.
Geothermal power is cost effective, reliable, sustainable and environmentally friendly, but has historically been limited to areas near tectonic plate boundaries. Recent technological advances have dramatically increased its applications, such as home heating, opening a potential for widespread exploitation to help mitigate global warming.