00:00 Geothermal energy is the process of tapping into the heat deep inside the Earth to create electricity, with the Earth's primordial heat and radioactive decay being the two main sources of this heat.

01:39 The Earth's interior contains enough heat in just the top 10 kilometers of the crust to provide all of the energy for humanity for over 200 million years.

03:19 Geothermal energy has been harnessed for centuries, with the first geothermal electricity being produced in Italy in 1904, and today, Lardorello in Tuscany produces 10% of all geothermal electricity in the world.

04:48 Geothermal power is produced by heating up a fluid with a low boiling point, which then turns to vapor and runs through a turbine, and while there are currently 11 gigawatts of electricity produced by geothermal power worldwide, the total amount of electricity provided by geothermal is only 1% globally due to the expense and difficulty of accessing heat in locations away from current geothermal power plants.

06:22 Drilling through igneous rock is more difficult and expensive, and to access the heat needed for geothermal power, drilling must reach about 4 km or 2.5 miles deep, and groundwater is also necessary, but there are risks involved with pumping water into fractures within the rock, such as creating earthquakes, although there have been developments in using high-powered microwaves to reduce drilling costs, and geothermal heating and cooling is a simpler alternative to geothermal electrical generation.

07:47 Ground-sourced heat pumps are a simple and efficient way to harness the earth's heat for heating and cooling buildings, saving energy and reducing bills, and they work especially well in cold climates and greenhouses.

09:13 Ground-sourced heat pumps and geothermal heating are widely applicable and should be installed in new homes, according to the host.