Thursday, March 5, 2015

Getting to Zero: ENERGY SENSE FROM AN UNLIKELY SOURCE

This diary is part I of GETTING TO ZERO: Our non-fossil energy future.

attribution: None Specified
Human civilization depends on food, food depends on weather, and weather depends on climate. Every grain and every mammal on the face of the earth – almost everything we eat – evolved under a different climate than the one we're heading toward. We are running toward a cliff, and merely walking toward that cliff isn't a viable strategy. We need to stop. Right now.
If civilization is to survive, we need to get to zero emission of fossil carbon, and we need to get there rapidly. Every ton of carbon we emit stays in the air for centuries, and will continue to warm the planet for centuries.
In this series GETTING TO ZERO we will take a very hard-headed look at current energy policy and energy strategies. We will ask hard questions: does this really get us to zero? How much would it cost? How rapidly can it be deployed? We may find some answers along the way, but don't expect them to be easy.

Part 1: The Size of the Problem



The fossil addiction
We've all read those rosy optimistic stories about renewable energy, and how in some given month 100% of new electrical capacity in the US was all renewable; or about how during some hour in the dead of night all of the electricity demand in Denmark was met by wind. You read those stories and you think, "Hey! We're making progress in the climate fight!"
And that impression is dead wrong. We're not making progress, we're going backwards. It's just that we're going backwards a tiny bit more slowly that we would have otherwise.
Here's a graph. Look at it closely. Study it carefully. And then try to project, on the basis of this graph, the year in which the world will stop burning fossil fuel:

attribution: None Specified
If you look way down at the bottom of the graph, that green line is renewables. Do you think that's tiny? You don't know the half of it. Most of that green line is biofuels, and only a tiny fraction of the green line is solar and wind. If solar and wind had been broken out separately, they would both be hugging the axis. Let's put it this way: ALL the growth in ALL non-fossil energy during the last 10 years, combined, adds up to less than 20% of the growth in fossil fuels during the same period. (It's actually 18.6%). It's not just that we're not using less fossil fuels, its that we're not even close to using less fossil fuels. But to solve the climate crisis, that big gray hump on that graph has to go all the way down to zero. Or at least it has to be hugging the axis, right where solar and wind are now.
Are you frightened yet? If not, you should be. Because this graph might very well represent the end of civilization as we know it.
Agriculture. It's what you eat.
In 1848, more than forty nations across Europe underwent simultaneous revolutions. It wasn't the internet or twitter that caused that; it was crop failure. The price of food went way up, so people spent all their money on food and none on manufactured goods. With no demand, the factories shut down. And suddenly, Europe was full of unemployed hungry people. And hungry people do desperate things.
Then in 2011 it happened again, and nobody noticed. In the summer of 2010, Russia had the biggest, hottest heatwave of its history. That caused the Russian grain harvest to nosedive. The Russian government responded by banning grain exports, which meant that the Russians didn't feel the pinch; instead, the pinch was felt by those countries the Russians had been exporting to. Among those nations were Tunisia, Libya, Egypt, and Syria, where the price of food went way up. And all four of those nations underwent simultaneous revolutions starting in the spring of 2011: the "Arab Spring." Hungry people do desperate things.
So what happens the next time? What happens if the next time one of the countries affected is India, or Pakistan, or China, or North Korea, all of which have nuclear weapons? Hungry people do desperate things, and a desperate person with a nuclear weapon is a very bad idea. Is it any wonder that a Pentagon-commissioned study in 2007 projected that climate change will be a major catalyst for terrorism? (And they were right).
When we think about the impact of climate change, most people think of hurricanes, superstorms, rising sea levels, wildfires, and lost ecosystems. All of those are important, but the fastest way we will kill ourselves is just by killing ourselves: civilization rises or falls by the food supply, and everyone's safety depends on the social contracts and mutual trust of a functioning society. If that breaks down, society collapses. Ask anyone in Syria or Somalia, and they'll tell you.
When T. R. Malthus published his Essay on the Principle of Population in 1798, he saw the rapidly rising population of the world and predicted a famine that would hold population in check. He was wrong about both the famine and the population, because he failed to see the impact of industrialization – i.e., the use of fossil fuels – on agricultural production. First motorized tractors, cultivators, and reapers caused production to increase; then the introduction of fertilizer caused to to increase again. Then pesticides caused it to increase again. Today the debate is whether we should deploy genetically modified crops, which have the potential of further increases. The answer to that question may depend heavily on future climate, and the social environment it fosters.
But it is the intensive use of energy that has allowed all of those increases in agricultural productivity. The production of fertilizer requires nitrogen fixation, which is a highly energy intensive process. In effect, we eat the energy of fossil fuels, via the application of modern fertilizers to agriculture. Chemical pesticides and GMO research are likewise supported by the modern energy-intensive industrial economy, although not to the same scale as fertilizer.
This leads us to a very important concept: EROI, or Energy Return On Investment. It's a way of accounting for the energy inputs and outputs of any energy generating activity. For animal-powered agriculture, EROI is about 5 to 7. That means you get 5 to 7 units of energy out of it for every 1 unit of energy you put in to it. Before the Industrial Revolution, that was (almost) the only energy producing activity there was, and over 90% of the world's population was engaged in that activity, to be able to support the less-than-ten-percent of people who did everything else useful.
But modern agriculture, with its diesel-powered tractors, high-energy fertilizers and pesticides, has a much, much lower EROI. Today agriculture in the US has an EROI of about .09 to .17, which means we put a lot more energy -- mostly fossil fueled energy -- into agriculture than we ever get back as food. And those inputs are absolutely essential if we want to maintain the current level of global food supply. Without it, most of the world's population would starve.
The non-fossil solution
So here's what we need to solve the climate crisis:
1. We need a cheap, abundant supply of electricity that is fossil-free, and also free of hidden fossil fuel dependencies.
2. We need a cheap, abundant supply of non-fossil liquid fuels for transportation, particularly aviation and heavy trucks. This also needs to be free of hidden fossil fuel dependencies.
3. We need a cheap, abundant supply of high-temperature non-fossil process heat for industrial applications, such as smelting metals and manufacturing ammonia for fertilizers.
Ideally these solutions should be deployable anywhere in the world, that is, not dependent on specific geographical factors. Alternatively, we might be able to finesse that requirement by a combination of geographically dependent technologies that are diverse enough to cover the globe.
Part II of GETTING TO ZERO can be found here. Is renewable energy economically viable?
Yes, yes, I know: publishing Part II before Part I? Bad kossack! Waiting 14 months between parts? Bad, BAD kossack!

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This diary is Part II of GETTING TO ZERO: Our non-fossil energy future.
Human civilization depends on food, food depends on weather, and weather depends on climate. Every grain and every mammal on the face of the earth – almost everything we eat – evolved under a different climate than the one we're heading toward. We are running toward a cliff, and merely walking toward that cliff isn't a viable strategy. We need to stop. Right now.
If civilization is to survive, we need to get to zero emission of fossil carbon, and we need to get there rapidly. Every ton of carbon we emit stays in the air for centuries, and will continue to warm the planet for centuries.
In this series GETTING TO ZERO we will take a very hard-headed look at current energy policy and energy strategies. We will ask hard questions: does this really get us to zero? How much would it cost? How rapidly can it be deployed? We may find some answers along the way, but don't expect them to be easy.
Part 2: Is renewable energy economically viable?
An important new study in the journal Energy (Weißbach et. al. 2013, paywalled) focuses onenergy return on investment (EROI, or sometimes ERoEI), which is the ratio of electrical energy produced by a given power source to the amount of energy needed to build, fuel, maintain and decomission that power plant. Here is one of the main results from the paper (higher numbers are economically better):
EROI
PV=photovoltaic; E-66 is the Enercon 1.5 MW wind turbine model studied; CSP=Concentrated Solar Power (Sahara site assumed); CCGT=Combined cycle gas turbine; PWR=pressurized water reactor.
In this study, "unbuffered" is the raw generation without storage, while "buffered" includes the cost of pumped hydro storage where it is needed to buffer the difference in peaks between production and consumption (assuming, rather optimistically, that the geography is available for any amount of such storage facilities). Fueled energy sources already store energy in the fuel, so no additional buffering is needed there. The hydropower system analyzed is a run-of-river type (i.e., no dam or reservoir), which has a very favorable EROI, but would require buffering at some times of the year if deployed en masse.
A couple of important points: first, these are energy costs and outputs, not monetary costs, which can be entirely different. These numbers represent technological ability only. Second, every source shown here has an EROI greater than 1, which is break-even. In other words, each of these generates more energy during its lifetime that the energy used to make and maintain it. That's good. But note the gray area at the bottom labeled as the economic threshold. To understand how this is arrived at, we need to take a major digression.
First we need to understand that not all energy is created equal. Electrical energy is very useful, because it can immediately do work. Heat and chemical energy are less useful because it's harder to get work out of them. This introduces an important concept: exergy, which is available energy, or energy usable for work. In general a large heat-type power plant (coal, gas, or nuclear) will require 3 joules of heat energy to create 1 joule of electrical energy. Therefore it is common to weight electricity by a factor of 3 when computing the exergy of a system. (Note also that unlike energy, exergy can be created and destroyed.)
So instead of computing the raw EROI, as in the graph above, it can be more useful to consider the exergy equivalent, by weighting both the energy inputs and energy output by a factor of 3 when the energy type is electrical. Weißbach (pronounced "vise-bach") calls this EMROI, and the results are shown below.
EMROI
Since all these sources produce high-weight electricity as output, but not all energy inputs are electric, the EMROI of all sources is higher than their EROI. What we've done here is taken one step toward monetizing the EROI, by allowing for the greater monetary value of electricity compared to other energy types. (This gives us Energy Money Return On Investment, EMROI). A fully monetized ROI would include non-energy inputs like labor and capital, which can be very large. That means a fully monetized ROI will always be smaller than EMROI. In effect, EMROI is a theoretical "best case" scenario for monetary ROI.
But note that the economic threshold has increased in EMROI too. Here's how those thresholds are computed:
... an EROI threshold can be roughly estimated by the ratio of the GDP to the unweighted final energy consumption while an EMROI threshold can be estimated by the weighted final energy consumption (which is not the primary energy consumption). For the U.S., for instance, the GDP was $15 trillion in 2011 while the unweighted end energy consumption was about 20 trillion kWh, resulting in an “energy value” of some 70 cent/kWh (Germany ~135 cent/kWh). The average electricity price, however, is 10 cent/kWh [10], (Germany ~18 cent/kWh) so there is a factor of 7 higher money to energy ratio on the input side. The same calculation for the weighted final energy consumption (the electricity demand was multiplied by a factor of about 3) results in a ratio of about 16 for both countries, assuming average primary energy costs of 5 cent/kWh and 3.5 cent/kWh for Germany and the USA, respectively. A similar ratio can be seen for other countries which leads to the conclusion that the thresholds are 7 and 16 for the EROI and the EMROI, respectively, assuming OECD-like energy consuming technology. For lower developed countries thresholds might be smaller, thus making also “simple” energies like biomass economic.
Here's the idea in a nutshell: in the US, a kWh of energy (unweighted) costs about 10 cents but it produces about 70 cents worth of GDP, a ratio of 7 to 1. (Note the switch: we're talkingmoney now, not joules.) If we do the same computation in exergy terms, the ratio is 16 to 1.  That means the fully monetary ROI of exergy, for the economy as a whole, is 16. But remember that if we have an exergy source whose EMROI is less than 16, its fully monetary ROI must be less than that -- which means that deploying such a source on a large scale will reduce GDP. The economy becomes less efficient as we deploy less efficient energy sources to run it. As we spend more of our time and effort making exergy, we will spend less making all the other stuff we need and GDP goes down. The flip side of this is that as the price of electricity goes up and GDP goes down, the economic threshold decreases: more marginal energy sources will become profitable.
Solar PV and biomass both fall below the current threshold, and wind would too, if we deploy it widely enough to require storage buffering. Concentrated solar thermal beats the threshold (at least in the Sahara desert case, and presumably the southwestern US would be comparable.) There are limited areas in which it could be deployed, but it makes sense to do so.
Wind is a tricky case. If you ask most people, they will tell you that we don't currently have energy storage for wind. In fact we do, but the buffering for wind comes from natural gas powerplants, which are typically built at the same time wind is deployed. When the wind dies, the backup gas plants are turned on, to keep the grid power reliable. Thus the energy storage for wind is embodied in the natural gas that isn't burned when the wind turbine is producing peak output.
This means that wind, as it's used now in the US, isn't really zero-fossil. It's a hybrid system that's part wind, part natural gas. And considering the availability of wind (30% is typical for a wind turbine), most of the energy actually comes from the fossil side of the equation. We're using the wind to offset some of the CO2 emissions from the gas plant (which is good), but instead of getting to zero, we're just walking toward the cliff instead of running toward it.
Denmark currently is one of the most wind-energy-intensive countries in the world, which works because they buffer their wind energy against hydroelectric power from Norway and Sweden. When the wind is blowing in Denmark, they export electricity to Sweden, which then can turn down its hydro plants (thus keeping more water stored in the reservoirs behind the dam). When the wind dies, Sweden turns up the taps on the hydroelectric production, and exports that stored energy back to Denmark. It's a great zero-fossil system, but it's only possible because of the unique geography that places a flat windy country right next to a couple of wet mountainous countries.
Finally, it's important to note that the grid-buffering sources for wind (hydro in Denmark, gas in the US) both have a higher EROI than wind itself. Thus these hybrid systems do make economic sense, but that's partly because the buffering portion makes economic sense on its own. Essentially, these hybrid systems dilute the EROI of hydro or gas, in order to subsidize the EROI of the wind portion of system. For the hybrid gas system that makes sense, because the reduction in CO2 is worth it. For the hydro-buffered system, the question is more problematic. In any case, it's clear that if wind had to be buffered with a non-generating storage-only system, the economics would be difficult to justify.
But the big winners in non-fossil energy are run-of-river hydro (Weißbach allows a 100 year plant lifetime, which may be generous) and nuclear (at a 60 year plant lifetime, in line with other studies). And by the way, this is one reason Weißbach's study is better than some earlier works: he includes plant lifetime in his computations, which can make a big difference. Wind turbines, for example, are subjected to large physical stresses which limits their lifetime to about 20 years, both in this study and according to the National Renewable Energy Laboratory. In effect, you have to build a windfarm two or three times over during the lifetime of a nuclear plant, and that adds up.
Two cases were analyzed for coal, one hard coal (EROI 29, EMROI 49) and one brown coal (EROI 31, EMROI 49). These were averaged to an EROI of 30 as shown. In the US we have plenty of hard coal reserves and don't use brown coal. Also, the authors omitted from this study the energy cost needed to transport coal, apparently because that varies by country. Using EIA data, this amounts to 244 KJ per tonne-km for rail transport. So in the US, where a lot of coal is moved from mines in Wyoming to end users far away, a  typical 1000 mile trip would lower the EROI of coal from 29 to 28, while EMROI remains unchanged at 49.
It's interesting to note that other studies have put the unweighted EROI of Canadian tar sands between 4 and 6, below the economic threshold. But since the output of tar sands is non-electrical energy, its EMROI decreases compared to EROI, which would put tar sands even farther below the economic threshold in exergy terms. So instead of building Keystone XL, Canada's economy would benefit far more by putting a lot of hydro in the Rockies and building a powerline instead of a pipeline. If Obama nixes the pipeline (as he seems poised to do), perhaps someone in Canada will take a harder look at the dismal economics of it. Or we might have to wait until Harper is out of office.
EROI isn't a new concept, and there are a lot of similar studies out there already. Weißbach has taken a good look at the previous literature and identified and corrected inconsistencies in many previous works. Most especially, the EROI of nuclear power in previous studies has been notoriously all-over-the-map, and Weißbach has pointed out a raft of errors, omissions, and uneven-handedness in earlier works, both those that come out above and below his result. Also, Weißbach has used the most up-to-date databases available on the energy embodiments of materials, which are required to compute energy inputs.
One reason previous studies on nuclear have been all over the map is that it's a moving target: the EROI of nuclear has been rising rapidly during the past 20 years (and will continue to rise) as the industry switches from gas-diffusion enrichment of uranium, to centrifuge enrichment (which is 35 times more energy efficient). Since uranium enrichment is a major part of energy input, this makes a huge difference. A nuclear plant using 100% gas diffusion would have and EROI of 31, EMROI of 34, comparable to coal. Weißbach's numbers above are based on 83% centrifuge, 17% diffusion. The World Nuclear Association projection is that there will be no more diffusion enrichment anywhere in the world by 2017. With 100% centrifuge, nuclear will have an EROI of 106, EMROI of 166 according to Weißbach's analysis. In other words, the switch from diffusion to centrifuge roughly quadruples the overall energy efficiency of nuclear power.
Beyond that, there is a new laser enrichment process being developed called SILEX which promises to be 10 times more energy efficient than centrifuge. And even beyond that, some Gen IV reactor designs (the fast neutron reactor, and the liquid-fuel thorium reactor, or LFTR) don't use enrichment at all, and could therefore come in at EROI of about 114, EMROI of 187. The LFTR in particular can't melt down and produces almost no long-term waste, which is why the Chinese are working on one right now. They've got 300 engineers doing the design, based on US research into liquid fuel reactors from the 1960's and 70's. (Your tax dollars at work -- in China.) The fast neutron reactor can use our existing long-term nuclear "waste" as its fuel, which is why the Russians have them, China and India are building them, and the British are considering it.
So if you ever wondered why climate scientists like James Hansen are pro-nuclear, this is one reason. Yes, wind is fine if it can be grid-buffered against a non-fossil generating source. And absolutely we need more hydro, especially run-of-river hydro where it's feasible. But there are limits to the amount of river where it is feasible. So if we want to eliminate fossil fuels from electricity production (and we do), and if we want to manage that transition so that it doesn't hurt the economy (and we do), nuclear has to be part of the mix. And in fact, it has to be a much bigger part of the mix than it has been in the past. In the next part of GETTING TO ZERO, I will address the safety issues of nuclear power in detail, but for right now what you need to know is that even after accounting for latent deaths from Chernobyl (and non-deaths from Fukushima), nuclear is still one of the safest forms of energy.
Finally, if you'd like to take a detailed look at the calculations, Weißbach's spreadsheet can be found on Google Docs. I used the spreadsheet to compute some of the numbers above.
Citation:
Weißbach, D., G. Ruprecht, A. Huke, K. Czerski, S. Gottlieb, and A. Hussein. "Energy intensities, EROIs (energy returned on invested), and energy payback times of electricity generating power plants." Energy 52 (2013) 210-221.
ISSN 0360-5442, http://dx.doi.org/....


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Sometimes a brilliant scientist, working alone, discovers something very, very important and nobody notices.
attribution: None Specified
Human civilization depends on food, food depends on weather, and weather depends on climate. Every grain and every mammal on the face of the earth – almost everything we eat – evolved under a different climate than the one we're heading toward. We are running toward a cliff, and merely walking toward that cliff isn't a viable strategy. We need to stop. Right now.
If civilization is to survive, we need to get to zero emission of fossil carbon, and we need to get there rapidly. Every ton of carbon we emit stays in the air for centuries, and will continue to warm the planet for centuries.
In this series GETTING TO ZERO we will take a very hard-headed look at current energy policy and energy strategies. We will ask hard questions: does this really get us to zero? How much would it cost? How rapidly can it be deployed? We may find some answers along the way, but don't expect them to be easy.
This diary is part III of GETTING TO ZERO: Our non-fossil energy future.
There are a lot of strategies for getting us to zero fossil fuels, and nearly every one of them features increased energy efficiency as a key component. The IPCC thinks so; theInternational Energy Agency agrees; efficiency is one of the famous "Climate Wedges" from Princeton; it's a key strategy of Amory Lovins' Rocky Mountain Institute; renewables guru Mark Z. Jacobson relies on efficiency for energy demand reductions of 30% to 40%, more than any other emissions strategy. And the list goes on.
There's just one problem. They are all completely and totally wrong. Increasing energy efficiency does not, has not, and will not ever reduce overall demand for energy. This is not just an opinion; it has been demonstrated with the cold hard equations of physics, based on the second law of thermodynamics.
Now don't get me wrong. Energy efficiency has obvious economic benefits, and those benefits are often enough to make such improvements worthwhile. It's not that we should stop being more efficient. It's just that we should not expect those improvements to reduce energy demand or carbon emissions. Because they won't do that.
The reason efficiency doesn't actually reduce energy demand is because of what's called the rebound effect (sometimes called the Jevons Effect, or Jevons Paradox, after its discoverer). The issue is this: if we're doing some economic activity -- let's call it Activity X -- that activity will take a certain amount of energy. If we then discover a more efficient way of doing Activity X, it will use less energy. But that will also make Activity X cheaper to do, and by the law of supply and demand, when something gets cheaper demand for it will go up. That's called the primary rebound, or direct rebound. What most people (even most economists, who study this sort of thing) miss is that there is also a "secondary rebound", in which the money saved by the newly efficient Activity X goes instead to buy more of Activity Y and Activity Z. In other words, the efficiency improvement results in a net economic improvement, and the improved economy demands more energy. When you include the secondary effects, that eliminates all of the energy reductions, and more.
So, are all these smart people, like the IPCC and the Rocky Mountain Institute, unaware of the rebound? Of course not. There are dozens of academic papers about efficiency rebound, with dozens of little case studies of this or that efficiency improvement, tracking what did and didn't happen next. One problem is that most of these studies are done by economists, and nearly all of them look only at the primary rebound and not the secondary one. That's because it turns out to be really, really hard to track all the effects of an efficiency improvement all the way through the whole economy and make sure you've got them all. So most don't even try, and even the ones who do try miss things. The result is that nearly every study that looks at rebound comes up with a figure of, say, 20% or 40% or even 60% for the rebound, which still leaves a healthy margin for some energy/emissions reduction from efficiency gains.
And the other problem is, sometimes a brilliant scientist, working alone, discovers something very, very important and nobody notices. As in this case.
Dr. Timothy J. Garrett is an atmospheric scientist at the University of Utah, and climate change has been at the forefront of his work for a long time. Being a physicist, he takes a physicist's view of things. Some years ago, he developed a new framework for studying broad, long-term issues of civilization and climate: he conceived of human civilization, all of it, as one gigantic thermodynamic heat engine, and applied the basic laws of thermodynamics to civilization as a whole. Instead of looking very closely at the trees, Garrett sees the forest. The implications of that view are profound, and not particularly cheering.
The bottom line from Garrett's equations is that increasing the energy efficiency of civilization as a whole must necessarily also increase economic activity by similar amounts, which will result in no overall energy reduction at all -- ever -- from energy efficiency. The rebound effect cannot be less than 100%. If we are relying on energy efficiency to save us, that reliance is doomed to failure.
Garrett's work implies that there is one and only one strategy that can save our climate, and our civilization from self-destruction. We must switch energy sources away from fossil fuels, and rapidly.
One final note. Last week, the New York Times published an op-ed by Michael Schellenberger and Ted Nordhaus of The Breakthrough Institute (BTI) discussing the rebound effect and its implication that energy efficiency is inadequate as an emission reduction strategy. That op-ed prompted a secondary posting at The Energy Collective (TEC) by BTI's Jesse Jenkins, which in turn prompted a strong reply in favor of efficiency by the NRDC (Natural Resources Defense Council). Not one of these knowledgeable people or institutes mentioned Garrett's work.
But I did mention Garrett, repeatedly, in the comment threads to these TEC postings. One of the commenters to Jenkins' post was NRDC's resident physicist, David Goldstein, who initially claimed that studies showing rebound effects were non-falsifiable (and therefore not scientific). When I informed him of Garrett's work, based as it is in physics and thermodynamics, he had no reply.

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