Google's green goals are extremely ambitious. The search giant aims to operate its entire business on carbon-free energy, 24 hours a day, 7 days a week, by 2030. At Google I/O 2021, the moonshot has received a welcome boost with the announcement it will turn to "next-generation" geothermal energy to power data centers and infrastructure throughout Nevada.
"We are the first corporate to sign an agreement to develop next-generation geothermal," Kate Brandt, Google's sustainability officer, told CNET in a call prior to I/O.
The agreement is with Fervo Energy, a clean energy startup aiming to "unlock" the potential of geothermal resources. Starting next year, Fervo will work with Google to begin to add geothermal energy to Nevada's grid. It would complement existing renewable energy sources in the area, pushing Google towards its 24/7 goals.
Geothermal power plants use heat from the Earth as an energy source. Deep below the planet's surface, radioactive material is decaying and magma is heating up water, which provides an almost limitless supply of energy, if you can get to it.
"It is a phenomenally great source of energy," says Graham Heinson, a geophysicist at the University of Adelaide. "And there is huge amounts of trapped heat in the Earth that could power enormous parts of the world."
Humans have been harnessing geothermal energy for millennia, wherever the heat travels up to the surface, like in a hot spring. The water at the surface is warm (or scalding!) because it was heated by the Earth during the Old Stone Age, more than 12,000 years ago.
In modern times, the heat can be harnessed by drilling wells into the ground and extracting hot water present there. This hot water (and steam) get pumped to the surface where they power a turbine and generate clean electricity. In Iceland, for instance, this "traditional" geothermal power is responsible for around two-thirds of the country's primary energy use.
And geothermal has one significant advantage over other renewable energy sources. It's always available.
"Wind and solar have been mainstays of our strategy, but geothermal is a great source of energy because it's on demand," noted Brandt.