My last post: Deconstructing the 100% Fossil Fuel Free Wind, Water and Sunlight USA paper – Part I Why no nuclear power? introduced my readers to the report in Energy & Environmental Science titled: 100% clean and renewable wind, water, and sunlight (WWS) all-sector energy roadmaps for the 50 United States (100% WWS USA hereafter). In that post I discussed the confusing decision by the authors (Jacobson, Delucchi et al. at http://thesolutionsproject.org/) to consciously ignore the option of nuclear power in their vision for a 100% fossil fuel-free future for the USA and the world. Today’s post will follow-up on my previous post by looking more closely at some of the assumptions underlying this proposed roadmap for our future. As I pointed out in my previous post, David Roberts at Vox.com likened any proposed efforts to achieve a 100% fossil fuel free future based solely on wind, wave and sunlight as requiring a World War II–scale mobilization. My intention in this post is to demonstrate that the proposed approach cannot be achieved, as designed, even with a World War II-scale mobilization. Rather, I intend to demonstrate that even a World War II-scale mobilization by the United States will fail due to an absence of the raw resources (specifically rare earth metals and lithium) needed to achieve the 100% WWS USA paper goal.
As discussed in my last blog posting, the most evident failing of the 100% WWS USA paper is that it lacks the critical data necessary to demonstrate how they will achieve their goal. That is, they describe in detail just how much tidal energy they will need to achieve their goal but they don’t provide any details as to how to ensure that the raw materials necessary to produce the technologies are available. Instead, like the case with nuclear power, all the critical details are in Jacobson and Delucchi’s earlier pair of papers titled “Providing all global energy with wind, water, and solar power”, Part I and Part II (called 100% WWS World Part I and 100% WWS World Part II hereafter). Thus the 100% WWS USA paper provides a broad overview (a strategy) but it does not provide a method to achieve that goal (the logistics). Keeping with the military theme of this post I will remind my readers of the old military saw: “strategies and tactics win battles but logistics win wars”. Well Jacobson and Delucchi’s work is strong on strategies but exceedingly weak on the logistics. So let’s start looking at the logistics.
I really couldn’t go much further in this post without pointing out my previous post On renewables and compromises Part II Rare earths in renewable technologies where I discuss rare earth metals (called rare earths hereafter) and their importance for renewable energy technologies. As I point out in that post, rare earths are the elements that have allowed us to develop all these incredible renewable energy technologies. Neodymium (Nd) is the "magic" ingredient that makes high-power permanent magnets a reality. Lanthanum (La) and Cerium (Ce) are what make catalytic converters work. Your cell phone, your LCD screen, your hospital's PET scanner all depend entirely on the existence of rare earths. To be clear, we are not talking about traces of the stuff either. A single large wind turbine (rated at about 3.5 megawatts) typically contains 600 kilograms of rare earth metals (ref). European Parliament researchers have established that major deployment of photovoltaic cells and wind turbines may have a serious impact on the future demand of 8 significant elements: Gallium (Ga), Indium (In), Selenium (Se), Tellurium (Te), Dysprosium (Dy), Nd, Praseodymium (Pr) and Terbium (Tb) (ref - admittedly some of those are not rare earths but are mined in similar mines/geologic formations).
So ignoring the issues with nuclear power in the 100% WWS USA paper, another significant problem with the 100% WWS World Part I paper is that the authors gloss over concerns about supplies of rare earth metals. Instead they appear to pretend that we have essentially limitless supplies of rare earths or where supplies are limited that we can easily access the complete planetary resource of these materials with little effort. In their 100% WWS World Part I paper Jacobson and Delucchi note that the annual production of Nd oxide (needed for windmill turbines and anything that needs a permanent magnet) was 22,000 metric tonnes in 2008. They then point out that their 100% world scenario would require 122,000 metric tonnes/year of Nd oxide. That is quite a shortfall considering we aren’t making any serious efforts to address that shortfall. While most manufacturers of electric vehicles rely on Nd in the same paper they wave away the need for Nd in electric vehicles by stating that we will come up with an alternative for Nd, like Tesla does using Lithium (Li). The problem is that by doing so they just punt the ball down the road since if we are not relying on Nd we are stuck relying on another limiting component Li (to be discussed later). Going back to Nd, Jacobson and Delucchhi wave their hands and look at the global Nd reserves. They suggest that the global reserves can handle their usage numbers for up to 100 years at which point the world will be out of Nd. The question never answered is whether the entire world is going to abandon their historic concerns and frantically mine every ounce of Nd they can find? In my earlier post I point out that any attempt to ramp up mining capacity will require significant political and ecological compromises which might turn out to be a bit challenging. Moreover, some nations may decide that they have other domestic uses for Nd and don’t want the entire planetary supply used to provide the first world with wind turbines?
Having talked about the big name rare earth (Nd) let’s talk about some of the lesser known but equally important ones. Many of my readers will remember that old quotation attributed to Benjamin Franklin that told of “how for want of a horse-shoe nail a kingdom was lost”. Well in the world of renewables that horse-shoe nail is likely the rare earth element Dysprosium (Dy). I will venture a guess that 99.99% of my readers could not place this element on a blank periodic table (I couldn’t and I once had to memorize the periodic table to pass an undergraduate chemistry course). Dy is a critical component of the permanent magnets used in wind turbines and electric vehicle engines and unlike Nd it appears in rare earth deposits in very low concentrations (ref). Over 99% of the world supply of Dy comes from Chinese sources (ref) and under current use scenarios China estimates it has about a 15-25 year supply of Dy (ref note this ref is a pdf file that needs to open on your computer). Because of this, the compound is the top rare earth metal on the US Energy Critical Materials Strategy list (ref) close behind are Nd, Europium (Eu), Te and Yttrium (Yt). Given its importance, and limited supply Dy alone has the potential to upset Jacobson and Delucchi’s version of a clean energy future. Certainly, if necessary, alternatives to Dy will be identified. But it is unlikely that any alternative will provide the efficiency that Dy does in permanent magnets which means that magnets without Dy will be less efficient and thus will not able to produce energy at the rate required to meet their future use scenario. Did you see how that worked? for want of Dy a permanent magnet was lost...for want of a magnet all turbines were lost, for want of all turbines a future scenario was lost. For those of you interested, I strongly advise reading how the US Department of energy is planning to deal with future shortages of these critical rare earths (ref). As I note above, Dy is not the only critical rare earth that is not being produced in any reasonable volumes in the Western world. Eu, Te and Y are also critical components of most of our major energy plans and at this time we simply lack any reasonable supply for them outside of China. What every environmentalist must understand is that any serious effort to move to a 100% renewable future can only be achieved if we make a conscious and concentrated effort to locate, mine and refine rare earth metals in the Western world.
Having discussed rare earth metals, let’s consider the major alternative presented by Jacobson and Delucchi: lithium. As any follower of modern tech trends will point out, Tesla is staking its battery business on lithium and cobalt cathodes and NCA ( nickel -cobalt- aluminum oxide) cathodes (ref). This is pretty much what Jacobson and Delucchi suggest will be one solution to the shortage of Nd. The problem is that each battery pack can contain a lot of Li. While Tesla has kept their numbers under wraps it has been estimated that each battery pack in one of those Tesla S 7000 powerwalls uses about 21.4 kg of Li (ref). In 100% WWS World Part I Jacobson and Delucchi estimated that the production of only 26 million electric vehicles would require 260,000 metric tonnes of Li. They point out that at that consumption level we would exhaust the current world reserves of Li in less than 50 years. While 26 million electric vehicles seems like a lot that is only half of the vehicles produced in the world on a yearly basis. Under their 100% WWS USA scenario Jacobson and Delucchi talk about electrifying virtually every mode of land transportation. That would mean a lot more than 260,000 metric tonnes of Li a year and that is only for electric vehicles. It completely ignores any other battery (like the Tesla wall units or even rechargeable AA’s) that might be used to help store all that solar energy that is being collected during the daytime but intended for use once the sun goes down. Jacobson and Delucchi point out that we can always extract Li from seawater; but they also point out that seawater extraction is a very energy intensive process. That energy has not been included in any of their energy budgets. So you see once again the picture looks fine from a distance but once you look up closely you see all these little flaws and like a knitted sweater, once you start pulling at the loose strings things start falling apart.
Well once again a post has got away from me. I was going to go on to discuss platinum but at this point that would simply be overkill. Rare earth metals and lithium form what we in chemistry call a rate-limiting step in the movement towards a 100% fossil fuel free future. Unless and until we can figure out some way to speed up or go around that rate-limiting step the grandest of plans is going to come crashing down to earth in the cold, hard light of day.
I am really embarrassed to admit that a legislator in New York actually submitted a bill to make New York State 100% fossil fuel free based on the NY WWS study. Fortunately the legislation did not go anywhere but any thoughts on what percentage of a renewable future is possible with the rate earth limits in place now?ReplyDelete
It depends on the renewable technology. Evidently a hydropower plant on the Congo River uses different amounts of rare earths per energy unit delivered per year.Delete
The answer also depends on the country and location. Are you referring to the USA, or to what´s left of humanity in 100 years? I think by then we should have exhausted most of the fossil fuels we are using, so the global warming issue will be very far down the list of critical needs. By then, if we haven´t figured out something, human population will be a lot smaller.
These are in fact wonderful ideas in concerning blogging.ReplyDelete
You have touched some good factors here. Any way keep up writing.