If you dig down for some 10 kilometres down, you are gonna find 50 times more energy than all the oil and gas we have.
You can see it with the naked eye, when the heat from the Earths crust warms underground reservoirs of water and then it goes all the way up and can be seen as steam and that is some energy which can be used and exploited.
The simple one: when underground steam goes into the turbine spinning it and making the generator produce electricity.
Another method is called flash steam. Hot liquid is driven into a tank on the surface, where it quickly gets cooled down and turns into vapour which drives the turbine.
Some advanced stuff called binary cycle power (invented in the USSR) where there are two liquids, one from the ground which heats another special liquid, which has a lower boiling temperature, which also evaporates and drives a turbine (Heat transfer fluid, it is called)
This geothermal activity is usually seen where tectonic plates of the earth meet and shift. Take a look at the map and you will see where you can mine for clean energy.
But hey, won’t that be an exclusive thing for Iceland and Indonesia?
Nope. Times marches on and so does progress. Engineers have learned how to dig into geothermal water layers and produce some power from that. And If there is no water there, like in Europe, the engineers just inject it into the bedrock, fracture it (destroy) and create a man made reservoir, which heats up and conveys the heat to the surface (otherwise known as hot dry rock).
The depth of such well would be between 3 and 10 km. It is rarely as big as 10 kilometres though. The deepest research hole was 12 (7 mi) km deep and was located in the Soviet Union. They couldn’t go any deeper, because, big surprise, it was too hot down there.
The water from the reservoir can be used directly to heat up and cool down buildings because the temperature a couple of meters below us is constant and if you run some water through the pipes, which then go into the house, it will be warming it up in winter and the opposite in summer.
Or, just use this energy to heat up a pool (that’s what I would do - I hate cold water). And that is what our ancestors did 5 thousand years ago.
This technology features low emissions, and small physical footprint - a phrase which here means - It doesn’t take up much space.
It is different from spot to spot, of course. In St. Rosa they inject wastewater into the soil to produce more geothermal energy and in some regions, it can bring some minerals out, which can be filtered and sold separately.
Yes, it is only a tiny-tiny speck of the overall energy game, but it is a reliable and consistent source and has a lot of undeveloped potential. Yet, if you do it like a moron, which is often the case, it can lead to a drop of underground temperature and then we are in big trouble.
If we look at the tectonic plate map again, we will see why the countries that generate more than 15 percent of their electricity from geothermal sources are El Salvador, Kenya, the Philippines, Iceland, New Zealand and Costa Rica. Because they are on the border of the tectonic plates.
Some downsides include possible emissions from the reservoirs.
Oh and it’s expensive as well to build a geothermal well. Yet, the saving from the direct use of the thermal energy, can be cheaper than fossils by 80%.
There is approximatively 14 thousand MW of power available today. Compared to hydroelectricity, which is explained in this video, it is not much. But the potential is impressive.
Free reliable heat. No emissions and doesn’t take much space, has a lot of potential
But expensive and need loads of preparations and is not that developed
It was fun talking to you about Geothermal energy, I am going to cover more renewables in other reports, so don’t forget to subscribe (and check out our Patreon channel (https://www.patreon.com/user?u=48890576) for awesome and witty travel diaries from Africa). You’re gonna love them.
If you have some additions, let me know in the comments. Remember, we all came to this video to learn - so the more you add, the better.