Understanding Modern Energy 3 – The Exponential use and depletion of Fossil Fuels

I have been teaching about energy for many years.  In all that time I have heard a great many people who expound on fossil fuels (FFs) that really have no idea of what is really happening concerning the use and depletion of this energy source.  Since we have been using them for over 200 years there seems to be an assumption that there must be an inexhaustible amount of them, even if the idea that they are finite is recognized.  In the last blog post I mentioned the ‘exponential function (EF).’  I have this description of EF from another blog I write: “The EF is also known as the power of doubling.  It can be applied to everything that grows or diminishes.  A very simplified formula that can be applied to calculate EF is 70/Growth Rate (GR) = Doubling Time (DT).  The number 70 is simply a round-up of the exponential doubling function 100ln2 (69.3).  If you know the GR or the DT then you can find a real number for growth.  For example, if you wanted to find the doubling time for the human population with a GR of 1% then 70/1 = 70 years.  So if the global population of people in 2000 was 7 billion, then at 1% GR the population would be 14 billion in 2070.  Without going into any more detail, simply realize that when you have a resource of say 100% of mineral Z and you have used half of the mineral (50%) then you are just one more DT from depleting that resource – 50% à 100% in one DT.  At 25% you are two DTs from depleting the resource.  If you found an extra 100% more mineral Z extra than you had before, then you are still only one more extra DT from depletion, since 100% à 200% in one DT.  The math is really simple.  Small numbers grow slowly to bigger numbers, then big numbers get monstrously bigger quickly.

Even if you ignore the pollution and waste problems, I have heard politicians and fossil fuel industry representatives exclaim that the data from ‘experts’ in the FF industries say we have enough FFs for hundreds of years.  For instance, headlines will claim that “at current rate of usage we have enough coal for a 1000 years.”  It is designed to mislead people.  Yet, as the Colorado University Physicist Al Bartlett used to say, “The headline is sort-of true but only under two very specific conditions that never exist.” Once we parse apart the headline, the assumptions for this to be true are that:

  1. All the known resource can be extracted. These resources are not like a glass of water where a full glass can be easily poured out.  Getting to the FFs is straight forward at first but becomes harder as the resource is removed.  As a very broad generalization only about 50% of the resource is recoverable (between 30-70% depending on many factors of extraction technology) and the economic reality is that as the resource becomes harder to extract, the rising cost of extraction becomes economically prohibitive to unfeasible.  For coal, the easily accessible coal seams start to become harder to mine.  For oil and natural gas, the large pockets are long gone and new invasive techniques are needed to get to the dregs at the bottom of the barrel, so to speak (more in next blog post about extraction itself)
  2. The headline says at ‘current rates of usage’ – this is crucial to understand because it talks about a linear rate of usage not exponential. That is, we use only as much next year as we did last year. And, the statement in the headline assumes that for the next 1000 years we will never increase usage per year but it is exponential not linear user that is currently happening.   What are the possibilities that we will immediately stop using energy exponentially.  One of the reasons we are using FFs exponentially is that while 15-20% of the industrialized countries have been using FFs for nearly 200 years, because of globalization the rest of the world is now coming on-board quickly with developing technology based on FF use, and only a few isolated places going straight to the renewable energy options.   Curiously, China was building a regular coal fired power plant at the rate of a 1000 MW coal fired electrical plant per week.  But China has now become highly invested in solar and wind as the reality of FFs hits home to them with extensive pollution problems, and limiting FF supplies that they now have to import at large cost.

If you go to the U.S. government’s own sites that give the FF supply status, and then apply the exponential function, the reality of FF supplies in the U.S. becomes alarming and surprising.  Peak of a resource is when the maximum rate of resource extraction is experienced.  After peak, the amount available then declines even as the demand increases.

  • Coal: At the current exponential rate of usage there is about 50 years worth of coal that can be recovered – this includes known and expected unknown resources, but recovery is going to be very costly from this point onwards. It has to be heavily subsidized by the government for it to make sense to continue extraction.  And as for the boondoggle called clean coal, it’s like saying clean dirt or clean mud.  What people who say this mean is that it is somehow possible to capture the carbon and pipe it under ground in old empty FF sites and old salt mines, etc.  That’s great as long as the deposition sites never leak and you have enough money to throw at the emissions capture system.
  • Oil: In 2008, a politician was busy telling us how we had billions of barrels of Oil in Alaska that would address our country’s needs. I asked my students to do find out what the known and expected unknown resources of Oil were in the USA.  They correctly came back and said there were about 50 billion barrels of oil total, but the country was using just less than 8 billion barrels a year at current exponential usage.   Even with efficiencies of oil usage the sad comment is that the USA has about 8 years worth of its own oil resources.  The ‘peak’ of oil in the USA was about 1974 and since then we have been busy draining the last major recoverable oil reserves in the country.  Even with off-shore exploration the best finds tend to be about 500 million recoverable barrels per site.  ANWR in Alaska, possibly the largest untapped oil research in the USA, which is part of the total 50 billion, has only 11 billion barrels – enough for about 1.4 years of oil if we had to rely just on that U.S. oil reserve.   Even from industry experts, the world is currently at peak oil now.  The largest oil fields in the world (Middle East) will no longer release data of the estimates of recoverable oil – a comment in itself as they strategize their economies for the future oil shocks.  All oil fields in the world are in decline with the exception of some of the Russian oil fields and the East Bagdad oil field in Iraq.
  • Natural Gas: The peak of NG with regular technology in this country was about the early 1970s. As large NG resources started to decline, a new technique, previously uneconomical to use, was set up – Hydraulic Fracturing (Fracking).  This allowed the energy companies to reach into widespread shale deposits where the confined gas pockets were highly variable pockets in size although some shales also contained small amounts of shale oil as well (its actually Kerogen that needs processing into oil).  The technology for fracking has existed since the 1940s but was never economically feasible until the price of NG started going up as supplies started to become limiting in the early 1990s.  Rather than just a vertical drill hole to a large pocket of resource, fracking allows drillers to drill down from one hole and then go horizontally in multiple directions deep underground.  The horizontal drill holes are then hydraulically treated to crack the ground rock deep down where the smaller gas deposits can be collected and piped to the surface.  OK, that’s a very simple explanation.  The reality is a bit more troublesome.  (More discussion in the next post.)

What is key here is that extraction of gas and oil via fracking is that recovering these resources means we are plumbing the bottom of the barrel of what was once there.  Coal is already uneconomical to extract.  In October 2018, yet another major coal mining site declared bankruptcy.  And out of the 20 major oil fields in the world, 18 are already well past peak and rapidly depleting.   As far as human societies go these FFs are all fast approaching the end of their useful life.  Yes, there are supplies for now but even as we continue to use them in the developed world, they are becoming exponentially depleted as more and more people in the developing countries that were not using them before start to increase their use of them.  Only last week (October 12, 2018), the International Energy Agency (IEA) released its monthly report that the world has hit “new twin peaks for global oil demand and supply” at 100 million barrels a day.  An optimistic report by the IEA based on industry reports of known oil resources is that the world has about 500 billion barrels of oil total.  A quick calculation based on world total with the latest daily oil use shows us less than 14 years of oil supplies at current rates.  And we keep acting as this is not a problem.

More about extraction in the next blog post.