Privileged Planet: Internal temperature extremely hot (Introduction)

by David Turell , Saturday, February 18, 2023, 19:25 (645 days ago) @ David Turell

Geothermal energy exists and is difficult o handle for practical uses:

https://mail.google.com/mail/u/0/#inbox/FMfcgzGrcjLbSNvRGltPDRjNvTbfHvKp

"All planets in the solar system, including Pluto, formed from the same ball of hot plasma as the sun. The major difference between our Sun and the planets is that it’s larger. And because the Sun is larger, its gravitational pressure can sustain nuclear fusion. Smaller clumps of matter, like our Earth, can’t do that. So, they cool, and before you know you have people driving around in pick-up trucks with bumper stickers complaining about the government.

"But it takes a long time for a planet to cool. Therefore, Earth is really still a ball of this hot plasma, just that it now has a crust on the outside where it’s already cooled. But when you dig, it gets warmer. And the deeper down you go, the warmer it gets.

"Scientists believe that the temperature at the Earth’s core doesn’t just come from this initial heat of the plasma, but comes partly from radioactive decay. But no one knows exactly, because no one’s been there, probably because the centre of earth is about as uncool as is gets.

"The temperature at the core of earth is an estimated five to seven thousand degrees Celsius, that’s about the same as the surface of the sun and my office in the summer. But we don’t need thousands of degrees. A few hundred degrees Celsius are sufficient to boil water and drive turbines with it. Such temperatures can be found in a few kilometres’ depth in most places on Earth.

"Just how deep you have to dig for that depends strongly on the location. In some places one doesn’t have to dig at all because steaming hot water bubbles out of the ground. On the Azores, they make stew by lowering it down into a hole and cooking directly with geothermal heat. In Reykjavik they heat the sidewalks in the winter with geothermal heat. But in most places it isn’t that easy.

"Geoscientists estimate that the total energy reserves in the upper 10 kilometres of Earth’s crust are about 10 to the 27 Joule. The total global energy consumption per year is at present about 5 times 10 to the 20 Joule. This means if energy demand remained stable, geothermal energy would last several hundred million years.

"You may suspect that it isn’t terribly realistic that we exploit all this energy and you’d be right. But a somewhat more realistic evaluation comes from the US Department of Energy. They refer to geothermal energy as “America’s untapped energy giant” and estimate that the generation of electric energy from geothermal sources in US has the potential to increase from presently about 3 point five Gigawatts to more than sixty gigawatts by 2050. Then it would provide 8 point 5 percent of the total US electricity which is a refreshing change from securing energy supply by invading other countries.

"And this is only for using geothermal energy for electricity generation. ‘Estimates are even more impressive if you include direct use, that is heating with geothermal heat. Researchers from the National Renewable Energy Laboratory claim that every house in the US could be heated from geothermal sources for millennia."

Comment: This is taken from a video presentation discussing the use of geothermal energy and describing the tremendous problems that have appeared. The portion I've presented tells us a great deal about our Earth. This attribute is not special to the Earth.