How’s that for a humdinger of a clickbait headline?
As clickbaity as it might seem, it is still true, but I freely admit that it comes with a couple of hippopotamus sized caveats.
Firstly, I should probably state that this article is about geology, geophysics and tectonic plates, and not as such about volcanoes, I do though hope that you my beloved reader will accept this little digression of mine.
Secondly, I should point out that I am a geophysicist working with volcanoes for a day job, specifically in regards of geothermal energy. For the last decade and a half, I have written dry reports to governments about the wonders of drilling large holes into volcanoes to extract energy.
It will probably not surprise anyone that governments enjoy dry reports, but not so much coughing up the money to build modern geothermal plants.
Normal bog-standard geothermal energy comes in three distinct flavours of extraction, the most common is when a household drill a shallow borehole in their garden to extract heat out of the ground. This is quite common in the northern part of the world, well at least in Sweden.
The next one is drilling into a geothermal field to extract hot water or steam for space heating and electricity production. Depending on the size of the field and your ambition you can extract anything from a few kilowatts to a few hundred megawatts.
This is done by using drilling techniques developed at the end of the 19th century during the initial oil-boom in the United States. In other words, a shallow hole, straight down to shallow or intermediate depth.
So far, the available extracted energy is depressingly limited.
The third version is far more exciting, and that is to drill into, or next to, a magma reservoir in an active volcano. This has already been done by the Icelandic Deep Drilling Project, and there is at least one large scale power-plant being in the permitting stage using this technique (caveat is here applied, I am involved in that one).
If you look at the drilling side, we are now well into the state-of-the-art techniques developed by the oil and gas industry during the last 100 years or so.
This form of geothermal energy will transform volcano rich countries and has the potential of solving roughly ten percent of the worlds current electricity needs in a sustainable and renewable way. Problem is that it is just not enough.
To meet the Paris Agreement, we need to replace all electricity produced by coal, gas, and oil-powered plants. And that is a whopping 61 percent to replace.
To compound the problem, if we all are good little ecological people and go electric when driving, then we need a further 36 percent more electricity than what is currently produced in the world.
On top of that the worlds electricity consumption is increasing with 5 percent per year as the developing world is catching up to the industrialized part of the world.
The ten percent that classical, and not so classical, geothermal energy can produce is now at best a partial solution of the problem.
Even with all the current hydropower electricity in the world, and a monster-sized expansion of wind and solar-power, it is not enough. Grid-storage and smart-grids are also only partial solutions to the problem.
Even with all these good and nice solutions we do not reach the target, we already notice this as rising electricity prices across Europe and the United States, and those prices will skyrocket in the next couple of decades.
Now some will jump up out of their chairs and scream “NUCLEAR!” But before you do that, please explain first how we will pay the 13 trillion (and counting) dollar bill that we have already accrued to clean up the mess that it has already produced. You can’t? Well, I sure as heck can’t either, so sit down and we will continue with geothermal energy which is what this article is all about.
The fourth way
In 1974 the Lone Star Production Company drilled the 1-27 Bertha Rogers Hole in Washita County, Oklahoma. At 9 583 meters depth they had not found any hydrocarbons, instead they hit molten sulphur that solidified around the drill-bit and the drill-pipe twisted off.
This borehole, and not Operation Mohole, set off a “drilling into the crust cold-war race”. Enter the Soviet Union and their Kol’skaya sverkhglubokaya skvazhina SG-3, more commonly known as the Kola Superdeep Borehole.
At 12 262 metres depth the (by now) Russians ran out of money, and the project was permanently shut down in 1994.
In 1987 Germany got into the drilling-race and the German Continental Drilling Program succeeded with a 9101-meter-deep hole into the ground.
As with all other cold war projects it was a game of brinkmanship, with just a thin wail of science draped on top to make it seem less ridiculous, at no point was geothermal energy a part of the equation.
There was thought heaps of data collected, and in that data, we find a couple of nice nuggets of golden information. In fact, they solved our electricity crisis without even realising it, or even caring about any future use of the collected information.
Crustal geothermal energy
For geothermal energy to work you need a surprisingly small temperature differential if you are just planning to warm up your house via a heat-exchanger.
If you wish to produce electricity more heat is definitely better. The gold standard is the temperature for dry steam found at a minimum of 275 Celsius at a pressure of 59.6 Bar. If the temperature is lower the steam will contain water-droplets that will damage the turbine-blades, and instead one must use either steam-cleaners or heat-converters and a lower-temperature superheated steam agent like ammonia. For any itinerant engineers, I know that I simplified this a lot, you guys aren’t the target audience in this context.
Bertha Rogers was drilled by oil-well roughneck’s working on a budget, so they did not write down long-winded reports about their findings, the just wanted black stuff to squirt out of the ground. Regardless, we still get a couple of nuggets out of them.
The first of those nuggets is that the absolute minimum temperature in the borehole at 9 583 metres was 115.2 Celsius, it was probably higher than that, but we only know that the sulphur was molten. They never wrote down the actual temperature to my utter dismay.
The second nugget is that they proved that even with the simpler technology of the 1970s it was feasible to drill that deep on a budget that would be reasonable if you are intending to drill many holes at the same place.
The budgeting issue will become important as a comparison to the next two boreholes.
The Kola Superdeep Borehole had no budget, instead the Soviet Union poured money into it, developing new methods of drilling, new record-breaking drill-rigs, and the cost in the end helped to ruin them (together with the arms race, mismanagement, the space race, and so on).
The Soviet Union never stated the cost for drilling the hole, but it was to all points and purposes mind-boggling.
Another thing to remember here is that the intent of drilling into the dense and cold Baltic Shield was to not get heat-problems while drilling. For geothermal purposes this was a nightmare place to drill into.
We did though get loads of geologic knowledge for the money, for instance the believed transition point at 7km from granite to basalt turned out to not be true, instead it was found to be metamorphic granite causing an inversion.
We also learned that the rock beyond this point was thoroughly fractured and permeated with water causing the rock to behave in a plastic fashion. We also learned about microscopic plankton fossils at the depth of 6km.
But the important part in regards of geothermal energy is that the temperature gradient was different than expected. It was expected that the coldest piece of crust known to mankind would be 100 Celsius at 12 kilometres depth, instead the readily available deep water was 180 Celsius.
At those pressure that temperature equates to 5MW of extractable energy. As a single 12km deep hole that is obviously not economically feasible even on the stingiest oil-drilling budget, but it is extremely interesting none the less, since it is a worst-case scenario.
The Hole of Germany
If we now move onwards to the Hole of Germany, officially known as the German Continental Deep Drilling Program at Windischeschenbach, we find the same fractured plastic geology permeated by hot water. Here we do know the cost, an eye-watering amount of 270 million Euro in 1987 value.
There they also tried to push in additional water into the rock, and it was found that it was possible to inject large quantities of water without losing well-integrity.
Before drilling the Germans constructed a drill-bit able to survive temperatures up to 300 Celsius, a temperature that was expected at depths of 10 to 14km. Instead, they found that temperature to be exceeded at 9.1km depth.
In geothermal terms they produced a well able to produce sustainably produce 12MW of electricity. That is borderline feasible on the famously stingy oil-drilling budget for a single well.
A thought experiment
Let us now formulate a hypothetic story. One morning Vladimir Putin wakes up after having nightmares about global warming. Covered in cold sweat from his nightmare he decides to solve this problem once and for all with geothermal energy.
He then picks up the phone and orders Gazprom to drill a geothermal well for every single square kilometre of Russia. For good measure he explains that if they do not comply, he will Putinate all of them. Happily having solved the problem he goes back to a restful sleep filled with far nicer dreams about the upcoming Russian Electricity-dominated world.
As ludicrous as this idea might seem we should do the math of this insanity to see if it would solve the problem, let us not bother about pesky economics at this stage though.
Let us here assume that Russia is as uniformly cold underground as the Baltic shield is on the Kola Peninsula.
First of all, Russia is big, 17.13 million square kilometres big. At 5MW per square kilometre this equates to 85 650 000MW, or 85 650GW, or 85.65TW. The combined production of electricity in the world is currently roughly 28TW.
Dang, did our hypothetical Putin just save the world with ample margin to spare? Yes and no, and at the same time.
You would obviously need 85 million 5MW power-plants, and the grid-infrastructure to connect all of them. The cost for all of that would be so high that no feasible electricity price would ever merit that, not even if governments subsidized this loony idea.
Making a more feasible case
Let us now try to make economically viable case of Kola-holes. After all, the hypothetical people at Gazprom are the best in the world at drilling oil and gas-wells on a budget, and they learned heaps of stuff from the original Kola-hole.
First, they would use multi-pad drilling. This is when you drill several boreholes tightly together from the same derrick-pad. They would probably spud up to 8 boreholes without the extremely costly dismantling, moving, and then rebuilding the derrick for each hole.
These boreholes would then be made to drift outwards at an angle from each other to increase the uptake area of energy. A single hole would be 30-40 million Euro, with the multi-pad system we are now down to 20-25 million Euro per borehole.
Our hypothetical skilled Russians would now pull out the mother of all neat drilling-tricks. They would use each of the 8 boreholes as a parent-borehole down to 8km depth, from there they would split drill 3 side-holes from the parent-borehole, giving 4 extraction-wells per each of the eight surface boreholes on the pad. The deft Russians have now 32 wells on hand giving 20MW per parent-borehole, while at the same time having saved 24 kilometres of drilling for the same effect. By now each well is well below 15 million Euro.
Here economy of scale kicks in as they build a 160MW power-plant requiring a single grid-link instead of 32.
Even at this point it would require an extreme price per kWh for it to be feasible, or that a government would subsidize the project, but it is not impossibly far out if the alternative is all of us dying from the effects of global warming.
But the salient point here is that the Kola Superdeep Borehole was drilled at the worst possible place, at all other spots on earth you would either need to drill less deep, get more heat, or both improvements at the same time.
Even if we would cherry pick places with drilling depths of “only” 7km with the ability of producing supercritical fluid out of water (373 Celsius at 220 Bars), we would still have enough places to extract from to be economically viable at a cost of less than 10 Eurocent per kWh. Obviously the hotter and shorter the better.
And, if we run out of suitable continental crust, we can nick yet another trick from the rulebook written by oil-industry and go out into the much thinner oceanic crust.
There is yet another nugget hidden in the remnants of our three example boreholes. As they drilled the deeper parts of the boreholes, they noticed curious bubbling in the drill mud used as it was pushed up. At the Kola site they noted that it was so strong that it behaved like it was boiling.
At both the Kola site and at the Hole of Germany they duly tested the bubbly stuff and found that it was hydrogen that was bubbling up. At the site for the Bertha Rogers Hole, they just noted that the bubbly stuff burned, but was not useful methane, it is though quite likely to have been hydrogen since it did indeed burn.
At no site there was any excitement about the hydrogen, no particular follow-up research was done, and to this day we do not know what processes at such great depth produces hydrogen. After all, it was not the holy oil that was discovered, so why would they be interested?
Several decades later it is easy to scream out of frustration at the wasted opportunity for research into one of todays most promising energy sources.
Saving the planet is filled with these small little oversights.
No single solution will ever be able to solve our looming energy crisis. Instead, the solution is to be found in many different solutions, that if combined efficiently solves the problem.
In reality the answer is simple and complex at the same time. We need smart grids, grid-storage, solar-power, wind-power, hydropower and geothermal-power.
Of the options above, geothermal power is the best partner to wind and solar in roughly half of the world, and often in parts of the world struggling with getting enough electricity as it is. It is a technology that has the potential to change the world economy in the same way that oil did back in the day, but without destroying the planet while at it.