Sunday, June 19, 2016

ERoEI is unimportant and is being used incorrectly

In this article I will show that ERoEI is unimportant by itself. It usually does not matter if ERoEI is increasing or decreasing. ERoEI provides no guidance about which sources of energy we should pursue, nor does it offer any guidance about how much net energy will be available to us in the future. By itself, ERoEI is a useless figure, unless it is lower than 1, which it almost never is. Although different sources of energy (such as coal or solar PV) have different ERoEI ratios, this means nothing important.

What is important to civilization (and to us) is the amount of net energy obtained from a source of energy. It is an amount of net energy (not a high ERoEI) which allows us to drive cars, fly airplanes, and so on. If we obtain 1 GWh of NET energy, then it does not matter if it came from a high-ERoEI source, or from a low one. What matters is the amount of net energy.

In turn, the amount of net energy depends upon two things: ERoEI AND the amount of gross energy. BOTH of those figures are required to determine the amount of net energy obtained. ERoEI by itself tells us almost nothing.

Let me provide an example, to demonstrate this point. Suppose you have a solar PV panel with an ERoEI of 3, which returns 1KW on average continuously for 30 years. In that case, the net energy provided by that solar panel is 175.2 MWh ((1*24*365*30)*(1-1/3)) over its lifetime. If, however you have ten such solar panels, then the net energy returned is ten times higher (1752 MWh), despite no change in ERoEI.

For the most part, the amount of NET energy we can obtain is determined by the amount of GROSS energy we can obtain, not by ERoEI. Usually, ERoEI is only a minor factor. This is because the difference in the amount of gross energy between sources of energy is so large that it completely overshadows any minor influence that ERoEI would have.

For example, suppose we had single 1KW solar panel, and the panel had a very low ERoEI of 4 (which is certainly an underestimate [1]). Even if you increased the ERoEI from the very low value of 4, all the way up to to infinity, so that no energy was required to replace that solar panel, it would make little difference--it would increase the amount of NET energy obtained by only 25%. On the other hand, if you could build 3 such solar panels, instead of 1, then you would triple the net energy obtained. In this case, building two more solar panels had 12x greater effect than increasing the ERoEI to infinity.

For the most part, the net energy obtained from solar power would be determined by the number of solar panels built, not by their ERoEI. In turn, the number of solar panels which can be built, is determined by non-energy factors like capital and labor, because those are the scarce factors which prevent the construction of more solar panels. Energy for investment is not scarce, because this planet is bombarded with 23,000 terawatt-years/year of solar radiation, which is vastly more than we will ever use. It is the scarce factors which determine how many solar panels we can build, and therefore, for the most part, how much net energy we will obtain. This point is complicated and requires further elaboration, so I will discuss it in a subsequent article. Suffice it to say, that the net energy of solar power is determined by non-energy factors such as capital and labor, and has almost no relation to ERoEI, because capital and labor (not energy) are the scarce factors which prevent the construction of more solar panels.

Generally speaking, the amount of net energy goes up as ERoEI declines, although it’s a weak correlation. This is because the amount of gross energy is vastly higher at lower ERoEI ratios, and the greater amount of gross energy more than compensates for any decline in ERoEI.

For example, solar PV could provide far more net energy than coal, regardless of its lower ERoEI. This is because solar radiation is so much more abundant that its lower ERoEI would be completely overshadowed by its greater amount. As a demonstration, suppose we could convert only 1% of solar radiation striking this planet into electricity using solar panels. In that case, we would obtain 40,000 times more electricity from solar power than we currently obtain from burning coal [2]. That figure does not take into account ERoEI, but it would make little difference. Even if solar PV had an extremely low ERoEI of 4 (certainly an underestimate), and coal had an ERoEI of infinity, it still would only reduce the maximum net energy of solar power by 25% relative to coal [3]. Since solar power is 40,000 times more abundant than coal, an ERoEI adjustment of 25% is not important. It would mean only that we could obtain 30,000 times more energy from solar power than from coal, rather than 40,000 times more [4].

Of course, if the ERoEI of some energy source were extremely low (like less than 2), then ERoEI would become an important factor. In that case, ERoEI would actually make a substantial difference, because it would cause a 50% or greater net energy loss. However, all common sources of generating electricity have ERoEI ratios far higher than that. With an ERoEI higher than 8 (which all sources of generating electricity have), the amount of energy spent obtaining more energy is only 12.5%, which is completely overshadowed by differences in gross amount between energy sources.

Again: net energy available is a function of BOTH EROEI AND AMOUNT. Either one of them by itself cannot be used to calculate net energy. If we wish to use a “rule of thumb”, then we should assume that MORE net energy is available at lower ERoEI ratios, but the correlation is so weak that it can’t be relied upon. In any case, ERoEI is not generally an important factor.

Unfortunately, ERoEI theorists do not realize any of this. Over and over again, they wrongly assume that ERoEI is somehow proportional to net energy. They assume that a higher ERoEI somehow implies more net energy obtained. This is a severe mathematical error, but it’s repeated endlessly throughout the ERoEI literature, across decades.

Let me provide some examples which I read just a few days ago:

“Look [at a] Cheetah… That beautiful and ultra efficient machine, needs an EROI of about 3:1... That’s a metabolic minimum EROI for mammals.Being the minimum EROI for any live being (mammals in particular) 2-3:1 in average, to be kept alive as species and for the couple to successfully breed their offspring (minimum of 2-3 per couple), probably Charles Hall is very right to state that a minimum EROI of 5:1 is required to have a minimum (very primitive and elemental) of civilization, beyond us living as naked apes.”
No, because that wrongly assumes that greater amounts of net energy are obtained at higher ERoEI. That is a basic mathematical error. Frequently, using a lower ERoEI source of energy will obtain more net energy than a higher ERoEI one.

The Cheetah example is also mistaken in other ways. The Cheetah doesn’t just have a low ERoEI; it also has TOO FEW prey which it can catch. If the Cheetah could eat prey every 5 minutes, then it would have a vast excess of energy even at an ERoEI of 1.5. The problem is that many animals eat only once per day and some animals (such as crocodiles) eat only once per week or so. The problem is amount, not ERoEI. If they eat only 10,000 kilocalories per week, then increasing the ERoEI wouldn’t matter much (even increasing ERoEI to infinity in this case would only gain the animal another 3,300 kilocalories). What would help is to catch MORE prey.

Here is another example of the same mistake:
We can take our ERoEI 20 FF and invest them in ERoEI 50 sources and make a huge energy profit. Or we can invest them in <5 and make a loss. Our policy makers have lost their heads electing to promote loss making activities.”

No, because that is confusing ERoEI with an AMOUNT of net energy. If an ERoEI were an amount, then spending fossil fuels with ERoEI 20 on solar panels with ERoEI 5, would imply a loss of 15. However, you cannot subtract the ERoEIs of different sources of energy, because they are not AMOUNTS which can subtracted. The correct mathematical operation is to multiply those two numbers, not subtract them.

If you take ERoEI 20 fossil fuels, and invest them in ERoEI 5 solar PV, then the aggregate ERoEI is 100 (invest 1 unit of fossil fuels initially, obtain 20 units of fossil fuels with ERoEI of 20 thereby, invest each of those 20 units in solar panels with ERoEI 5, then obtain 100 units at the end of it for an initial investment of 1).

Here is another example:
IMO, the only thing that could delay the bad impacts of declining high ERoEI FF is to introduce to the global energy mix an energy source that has higher ERoEI than the fuels they have to replace. Introducing low ERoEI energy sources simply makes things worse.”

No, because (again) that is confusing ERoEI with an AMOUNT of net energy. The “bad impacts” are caused by TOO LITTLE net energy, not a low ERoEI. Adding any source of energy with an ERoEI higher than 1 increases the total amount of net energy available. Only an ERoEI lower than 1 would make things worse. If the source of energy is cheaper per unit of net energy (as solar power actually is) then it is easier to obtain more net energy that way, regardless of its ERoEI.

…All three of the above quotations are taken from leading figures in the ERoEI literature, all published within the last few weeks. Granted, the ERoEI movement is a tiny fringe movement, but these people are among the leading figures of it. Over and over again, they wrongly assume that ERoEI and net energy are somehow proportional, and that higher ERoEI implies more net energy. That is a basic mathematical error. Frequently, the opposite is the case.

What matters is the AMOUNT of NET energy available to civilization, and that amount is far higher for renewables than for any other source, regardless of ERoEI.

* NOTE: In this article, I am using the term "ERoEI" to by synonymous with "EROI" and other spellings. I am referring to the amount of energy obtained for an investment of energy. If ERoEI for some energy source were extremely low (like lower than 3) then ERoEI would start to become more important, since we'd need to build significantly more power plants to generate the same net energy. Since all common sources of generating electricity have an ERoEI much higher than that, ERoEI is not important in any real-world scenario.

I revised this article on August 18, two months after its initial publication, to improve the flow of the text.

1. what matters is what it takes.
All the things in our world have an industrial history. Behind the computer, the T-shirt, the vacuum cleaner is an industrial infrastructure fired by energy (fossil fuels mainly). Each component of our car or refrigerator has an industrial history. Mainly unseen and out of mind, this global industrial infrastructure touches every aspect of our lives. It pervades our daily living from the articles it produces, to its effect on the economy and employment, as well as its effects on the environment.
The whole picture needs to be included not just the installed devices. I am not a supporter of fossil fuels or nuclear. I am concerned about continuing business as usual and its devastation of the earth and humanities future.
Solar and wind energy collecting devices and their auxiliary equipment have an industrial history. They are an extension of the fossil fuel supply system and the global industrial infrastructure. It is important to understand the industrial infrastructure and the environmental results for the components of the solar energy collecting devices so we don’t designate them with false labels such as green, renewable or sustainable.
This is a challenge to ‘business as usual’. If we teach people that these solar devices are the future of energy without teaching the whole system, we mislead, misinform and create false hopes and beliefs. They are not made with magic wands.
These videos are primarily concerning solar energy collecting devices. These videos and charts are provided by the various industries themselves. I have posted both charts and videos for the solar cells, modules, aluminum from ore, aluminum from recycling, aluminum extrusion, inverters, batteries and copper.
Please note each piece of machinery you see in each of the videos has its own industrial interconnection and history.
http://sunweber.blogspot.com/2015/04/solar-devices-industrial-infrastructure.html
http://sunweber.blogspot.com/2014/11/prove-this-wrong.html
Is this more elitist technology for the few. It seems to me all this promotion of solar and wind energy collecting devices are either envisioned as worldwide or it is simply more imperial colonizing of countries with resources and no power. Then think of the resources and energy required to meet global need for the global population.

1. Hi John,

Thanks for your remarks. However, what you've written is not relevant to the article you're responding to. I think you're trying to start a different argument.

I think the point you're making here is that solar panels indirectly require trucks, mining equipment, complicated infrastructure etc, and THAT runs off fossil fuels. As a result, using solar panels is just using fossil fuels indirectly, and we could never transition away from fossil fuels. Is that what you're getting at?

If so, then I think you're mistaken. Even if we can't transition the entire economy all at once to renewables, we can transition a big part of it, and could start now. If we used renewables to generate almost all electricity and we drove electric vehicles, then those things by themselves would reduce fossil fuel consumption by perhaps 70% (although not eliminate it). Doing so leaves us enough fossil fuels left over to last centuries. We could THEN transition the other things (like mining equipment) to use alternatives (such as synthetic fuels), and we would have more than enough time to manage THAT transition. We would do this in steps: the easy things first (electricity and EVs) and the hard things later (ships). This is the kind of asset allocation problem which market economies routinely carry out.

Best,
-Tom S

2. No, it is business as usual which your reply obviously supports that I challenge because the earth and it life forms can take it. I see you believe technology will save the world when far less people and far, far less resource use is necessary. We will never agree. There is the assumption that humans will change their ways and conserve energy and not consume, consume, consume. This is akin to Jevons' paradox (perhaps there is one more germaine). If the energy is available, what will stop continued consumption of tools and toys? Who will go first with this restraint and restricting? Think of the uproar if legislated.

It is comforting to prefer the noise of delusional magical thinking and pretending that the system of perpetual growth can work forever; that some variant of business as usual can persist. There is just too much tied up with it and any unraveling would be far too chaotic and unpredictable. Wrapping our heads around the eventualities of global warming; of overshoot; of the desecration of world wildlife; of the acidification of the oceans; of the poisoning of pollinators stymies.

A world no longer powered by fossil fuels, no matter what incarnation or fueled by nuclear, is almost inconceivable and for many terrifying. It is indeed traumatic for what it might (probably) means not just for us but also for our love ones, children, grandchildren. Our hearts break. We want to fix it. So we do more technology and more ultimate harm.

It is like a person diagnosed with lung cancer saying he/she will just smoke these organic, non sprayed cigarettes for a little bit longer instead of facing the reality of the situation, quitting and having the operation.

We are slowly technogizing ourselves into extinction. Technology is seductive. Is it the power? Is it the comfort? Or is it some internal particularly human attribute that drives it? Technology surrounds us and becomes part of our story and myths. Technology tantalizes the human mind to make, combine, invent. There are always unintended consequences with technology. It effects how we experience the world in time and space. It affects how we feel the world. If all the externalities were included in the prices and cost to nature, we would be very, very wary of technology.

I think we have moved from technology in the service of religion (pyramids and gothic cathedrals) to religion and culture in the service of technology. It isn't a deity that will save humanity but in the eyes of many - it will be technology.

We will do more of the same, business as usual until there are no more holes in the ground to dig, no more water above and below to contaminate, no humans to wage slave, no other lifeforms to eliminate. Yes, we are building Trojan horses in our hearts, minds and spirits. It will be elitist and entitlement and hubris – it will end with both a bang and a whimper.

1. Hi John,

I definitely appreciated your moving and poetic prose. You have a strong moral vision, a strong emotional revulsion to technology, and an ability to present those sentiments in a compelling way.

However, you've not said anything which disputes any claim I made, either in my earlier comment or in the article.

You may feel that technology is extremely bad, repulsive, or dehumanizing. I won't argue with you, because that's the kind of thing which is in one's heart, and there is no sense in arguing about that. If you find technology to be dehumanizing, and you wish to live in the forest, then I certainly won't deter you.

Nevertheless, these claims about declining ERoEI etc are FACTUALLY WRONG, no matter what you feel about technology. I need to point that out, and I hope you understand the reason. Some people moved to the forest years ago, not because they wanted to, nor because they hated technology, but because they were misled into believing that civilization was about to collapse. Some of them wasted years of their lives. What they needed was a better factual understanding of these issues, not a sermon.

If you find that technology corrupts your heart, or despoils nature, then living without technology may be right for you. What I personally want is to understand on a theoretical level what is happening in civilization. You may feel we're "building trojan horses in our hearts", but even if you were right, that is not the kind of understanding that I'm looking for.

Best,
-Tom S

3. I made no claims about declining ERoEI in my posts that I could find. However: A paper recently published in Energy Policy by Ferrucio Ferroni and Robert J. Hopkirk and titled Energy Return on Energy Invested (ERoEI) for photovoltaic solar systems in regions of moderate insolation. They used a similar methodology thart Charles Hall and Pedro Prieto used in their study for 4 GW in Spain. That is, they considered not only the usual energy inputs for modules and its components and/or some immediate accesories to them, but also some societal sine qua non energy input expenses for solar systems and concludes that in these regions (countries like Germany and Switzerland), the EROI is 0.85:1.

Scientific studies show it takes years to payback the energy used in solar electric devices. EROI (Energy Returned on Energy Invested) says it takes energy – mining, drilling, refining, transporting, installing, maintenance, and replacement parts – to make the devices necessary to capture solar energy.
Spain’s Photovoltaic Revolution: The Energy Return on Investment by Prieto, Pedro A., Hall, Charles 2013.
http://www.springer.com/energy/renewable+and+green+energy/book/978-1-4419-9436-3
and http://energyskeptic.com/2013/tilting-at-windmills-spains-solar-pv/
and B o o k R e v i e w : E n e r g y i n A u s t r a l i a - P e a k O i l , S o l a r P o w e r , a n d A s i a’ s E c o n o m i c G r o w t h by G r a h a m P a l m e r http://www.springer.com/energy/renewable+and+green+energy/book/978-3-319-02939-9

Spain’s Photovoltaic Revolution presents the first complete energy analysis of a large-scale, real-world deployment of photovoltaic (PV) collection systems representing 3.5 GW of installed, grid-connected solar plants in Spain. Prieto and Hall conclude that the EROI of solar photovoltaic is only 2.45, very low despite Spain’s ideal sunny climate. Germany’s EROI is probably 20 to 33% less (1.6 to 2), due to less sunlight and efficient rooftop installations.

“Solar advocates can learn from this analysis . . . “ Not looking at the reality of EROI “is not good science and leads to wasted money and energy that could have been better spent preparing more wisely for declining fossil fuels in the future.”

This study does not detail the environmental destructive mining, toxic chemicals or air and water pollution necessary to get the materials for manufacturing and installing solar devices. It is the sun not the devices that is renewable, green and sustainable.
For a take on "what is happening in civilization" (only one of many similar views) check out:http://sunweber.blogspot.com/2016/06/raising-children-wrong-turn-10000-years.html

1. Hi John,

"Prieto and Hall conclude that the EROI of solar photovoltaic is only 2.45, very low despite Spain’s ideal sunny climate. Germany’s EROI is probably 20 to 33% less (1.6 to 2), due to less sunlight and efficient rooftop installations."

Prieto and Hall have made a serious mistake in their EROI calculation. They are using an incorrect formula to convert dollars into energy as an estimate. When this error is corrected, the EROI of solar PV in Spain is higher than 5.

They also have two other mistakes in their analysis, in my opinion. They are counting the embedded energy of steel and aluminum for frames on the way in, but not counting the energy recovered when those are recycled. Also, they are wrongly assuming that the lifespan of solar panels is exactly identical to the warranty period. When those errors are corrected also, the EROI of solar PV in Spain higher than 6, not 2.45. This figure is SIMILAR TO (although slightly lower than) electricity generated from natural gas if you deduct waste heat losses. The slightly lower EROI of solar PV would make almost NO DIFFERENCE, because the slightly lower EROI would be totally negated by the vastly higher amounts available.

“Solar advocates can learn from this analysis . . . “

No, they cannot, because the analysis is mistaken.

John, one of the problems of this little pseudoscientific group is that it severely cherry-picks results. There is a whole body of researchers who conduct energy return analysis on solar PV. They usually call it "Energy Payback Time", not EROI. They have conducted careful studies and have concluded that solar PV has an EROI equivalent higher than 20, including mining, installation, transportation, and disposal. In my opinion, Hall and Prieto's figure is far lower because they have committed mistakes.

In this case, you are cherry-picking a single study because it spread like wildfire within the energy decline doomsday group. That study is a far outlier because it is mistaken.

-Tom S

2. Take your charges of mistake up with Charles Hall, Pedro Prieto, Ferrucio Ferroni, Robert J. Hobkirk and Graham Palmer.
There were three studies not a single study. Please let the authors know when you contact them that you see them as a little pseudoscientific group. Thank you for exposing yourself.

3. Hi John,

Once again, you're just not providing any kind of rational objection to anything I've written. Just saying "take it up with..." is not a defense of those ideas; its just bouncing the ball to someone else. YOU believe those ideas; why do YOU believe them? If you have no defense of those ideas and cannot defend them against elementary objections, then you have no serious reason to believe them.

In fact, I have brought these ideas up on a forum recently to Pedro Prieto and he offered no relevant defense.

John, it's obvious that this is a fringe pseudoscientific group. Why do you think this ERoEI stuff is ignored? Why do you think you only hear about it in places like peakoil.com? If civilization were really collapsing imminently and OTHER researchers seriously believed that, wouldn't it get a little more coverage?

Why do so many predictions fail so badly? Hasn't Charles Hall been warning about the fairly imminent decline of net energy to almost zero, since the early 1980s? What happened? Why doesn't anyone in this group even ask?

Also, doesn't science require some kind of replicable findings? Why do other researchers reach such drastically different results? Most importantly, why does this stuff seem to be IGNORED everywhere?

"Thank you for exposing yourself."

John, it is you who has exposed himself, not I. Whenever you encounter any kind of logical criticism, you just lash out and abruptly terminate the conversation. Much of what you write is just cut-and-pasted; I recognize it by now. You're free to do those things if you want, but what you're doing is not some kind of logical, scientific analysis.

-Tom S

4. Hi Tom,

I think your previous observation that the cost of net energy is a better measurement than EROEI is very compelling. Having said that, I think this post is a bit confused.

I think that perhaps there is some confusion about “energy”, what it means and how we use it. For example, there is a massive amount of heat energy in the oceans — but good luck using it! A better (more accurate) concept is of negentropy. As we move from a higher-ordered state to a lower-ordered state, we can extract work. It’s not the amount of energy, per se, it is our ability to perform work with it. I think this is what the EROEI proponents are trying to articulate with their measure. (However, I think your concept of cost-of-net-energy is an improvement, and that negentropy is better still).

We can see this at work all the time. Consider burning coal, to produce electricity. Of all forms of energy, thermal energy is lowest in negentropy. That’s why it’s so difficult to transform thermal energy into electricity, which is high in negentropy. The smaller the thermal gradient, the less negentropy is in the thermal energy (which is why we can’t perform work with small differences in temperature). If we then use electricity to heat something up, we’re “wasting” a high-negentropy resource for a low-negentropy task.

I think a better measure would be the cost of net negentropy. This captures the idea that you must invest negentropy (ie to extract oil or manufacture PV panels) to gain negentropy (the ability to do work)

When it comes to fossil fuels, the ratio of negentropy returned vs negentropy invested is high. Renewables may have a smaller ratio, implying less work done per negentropy invested in procurement. However, renewables are distributed which greatly improves efficiencies.

Thinking about your cheetah example, the limit is not just the number of prey available, but the cheetah’s ability to catch and metabolise them. Cheetahs can’t eat 50 times per day. And they can’t eat grass even though grass is available everywhere (this is a good metaphor for renewables vs fossil fuels). But animals can still thrive on a diet of grass, if different strategies are used.

Cheers, Angus

1. Hi Angus,

I definitely see your point with regard to negentropy. I think that's why it's necessary to provide an energy quality correction or to disregard waste heat losses from power plants when calculating the ERoEI of fossil fuels. I wrote that in one of my prior posts, and I agree with you on that point.

However, there are a few exceptions. What if I just burn coal to heat my home (as people used to do), just because I like my house to be warm rather than wearing a sweater? In this case, when we speak of "energy returns" we just mean burning something. It's not clear that anything different is happening thermodynamically than if we had piped oxygen and ignited the coal inside the coal seam. When we speak of "energy returns" in this case, we are talking about the coal being RELOCATED--from a coal seam to inside my house, because the energy is serving some purpose I have then.

Similarly, when the cheetah catches his prey, then the fat tissue of the prey is relocated to the Cheetah's stomach and eventually the cheetah's fat tissue, and will contribute to the Cheetah's future energy requirements rather than the prey's. I don't think anything different is happening thermodynamically there. Instead, it is now the Cheetah's energy rather than the prey's.

Thus, I think that "energy returns" are referring to energy which has been captured or relocated to serve some purpose of ours. This is true whether we convert the energy to electricity, as with the concept of negentropy, or just burn it to heat something.

As another example, suppose I am an astronaut in space on my way to Mars, and I have some mirrors aboard my spacecraft which focus sunlight to cook things. In this case I am converting a higher quality kind of energy (light) to a low-quality kind (heat). Still, I think that would be an energy return because I have relocated the light to do something I want, rather than letting it travel off into space. I spent some energy building the mirrors (energy investment), and then some energy was captured or relocated to do what I want (energy returns), even if I am greatly increasing entropy by doing so.

"Thinking about your cheetah example, the limit is not just the number of prey available, but the cheetah’s ability to catch and metabolise them. Cheetahs can’t eat 50 times per day."

Yes, that's definitely true. However, it is still the AMOUNT, not the ERoEI, which is primarily important here. If the Cheetah COULD catch twice as much prey per day, then its net energy would double regardless of ERoEI.

"And they can’t eat grass even though grass is available everywhere (this is a good metaphor for renewables vs fossil fuels)."

That is an excellent metaphor. There are far more grass eaters (and leaf eaters) than there are predators, despite the far lower ERoEI of grass or leaves. Grass eaters spend half their day eating, so the AMOUNT of net energy is greater despite an ERoEI which is probably very low.

-Tom S

5. By the way, I changed the article somewhat, by re-ordering some things for better flow. I also changed the wording of what I wrote about the Cheetah, based upon something Angus Wallace said. I also omitted a few things which I think were just repetitive.

6. Hi Tom.

I think that you are correct with net energy. But there is another factor, not EROEI or net energy but related that it's important.

It's the curve of energy return. Or time of energy return if you like.

A theorical PV that costs a lot of energy to be build and generate little power compared with the high energy to be build but it has selfrepairing and it's "eternal" it would have a very high EROEI and net energy in its lifetime, but it will return the energy very, very slowly. It could delay decades to return the invested energy even if it could generate "free" energy in the next millenia.

The time to return the energy is important for deal the hard transition to not use fossil fuels. The time to do it is limited, and too great "time of energy return" would limite our year growth and it could not be enough to compensate fossil fuels if they drops too fast.

We must notice that we should account the total energy investment to replicate itself, so we could theorically install new renewable over the base of more renewable.

7. Hi oatleg,

Thanks for your insightful remark. I definitely see your point. It seems possible that we could suffer an energy shortfall if we began transitioning to renewables too late, because (as you pointed out) it takes renewables a long time to generate net energy since all the energy is invested upfront.

Let me try to calculate what the shortfall would be. I will assume that we wish to replace all natural gas-fired plants with PV panels in some society. I will also assume that both PV panels and natural gas plants arrive and are installed the moment they are ordered which is always 12am on the first day of every year, for ease of calculation. I will also assume that both sources of power have an ERoEI of 10. I will assume that natural gas plants require 1/3rd of their energy investment upfront for the turbines, and 2/3rds of the energy is invested in extracting the gas, which is a guess based upon prices. Finally, I will assume that all gas turbines and PV panels last 30 years, and that natural gas is peaking today and will decline linearly to zero in 30 years. I will ignore intermittency for the moment.

Each year, we must replace 3.33% of our natural gas plants with solar PV panels. The investment in capital for solar PV requires us to "pay" an energy investment of (3.3*lifespan/ERoEI)% which is 9.9% of all energy production this year, and every year thereafter, whereas natural gas turbines required only 3.3% of all energy production as investment. As a result, replacing gas turbines with PV panels leads to a deficit of 6.6% of all energy produced every year.

However, there is another factor. We must subtract the energy investment for natural gas which is no longer used. The amount saved per year in gas goes up as time goes on (because 3.33% of turbines are retired), so it's a function of the year. It seems that the amount saved in gas would be (3.33 * 0.66 * year / ERoEI)%, where "0.66" was the fraction of energy investment in gas rather than turbines. This results in savings of energy invested of 0.22% the first year, 0.44% the next, and so on.

As a result, replacing gas turbines with PV panels would lead to a shortfall of ~6.38% of all energy produced the first year, ~6.16% the second year, and so on, diminishing to zero after 30 years.

I did this calculation fairly quickly, so please let me know if you arrive at a different result or think it's wrong.

I think the figure of 6.38% energy shortfall the first year is far larger than what we would actually encounter, however. We are beginning the transition to renewables long before fossil fuels have begun their decline. Furthermore, it will take much longer than 30 years for fossil fuels to decline to zero; even a conservative Hubbert curve indicates that it would take over a century. Also, we get some of our electricity from nuclear and hydroelectric which are not peaking.

As a result of those factors, I think the energy deficit will be lower than 2% in any given year and will decline over time.

-Tom S

8. From my perspective, if we simplify the fossils like the only cost is the fuel, in renewable we must invest multiple times the cost, at first, to allow the replacement at the same rate.

Fossil fuels has a limit of total fuel. It has not limits of power, but only energy.
Renewables, instead, could, when it has EROEI>1, generate net energy but implies at the same time a limit of power in a specific deploy timeline (although the total deployment is done the physical limits are high specially for solar and wind).

At deployment, we spend 1 energy unit. At the end of lifetime we obtain EROEI energy units.

EROEI-1 means the net energy units. ( NE= net energy)

EROEI/lifetime means how much net energy returns per year. It could express the speed limit of the selfdeployment of a energy source.
( NEPY = Net energy per year)

lifetime/EROEI would be the years needed to cover the energy investment.
( TOER = Time of energy return)

You assume for PV
EROEI=10

NE=9 (900% net energy factor)
NEPY=0,33 (33% per year energy return)
TOER=3

So, in terms of deployment, lifetime is as important as EROEI to compare.

Every year, we must spend a part of our energy to get new fuels. The lifetime of fuels is theorically, near 0. But in real, extraction, processing, transportation is a enough complex process to take some time. one year perhaps?
So, we could aproximate it's lifetime with this value.
Each year, we must spend 1/EROEI of oil to replace itself.
To get the same equivalent power in renewable, we must invest lifetime/EROEI energy to get the same power.

To invest the same energy amount of energy, the factor we must see is lifetime/EROEI.
So, for PV to be as fast a oil to be deployed, it would need to be x30 EROEI faster.

This seems horrible, but really is softer, because power is only a limit in deployment time.

For example, with 10 EROEI, we must invest 10% of energy in replacement. Other way to see this, it is that we have really 90% of deployed power to spare in our own consumption while the 10% should be spent in old power replacement.
With this 10% of energy, you could replace 3,3% power that it's just the obsolete power infrastructure.

If we deploy the power lineally, it would not be important, because in a 30 year frame, only 3% percent should be replaced, that means a extra 6% reduction effort to compensate the power lost, and after 3 years, the PV would generate extra "free" energy so the effort became smaller until it begins to be even less that the 3% in the old scheme, because the extra energy returned but PV is even cheaper that the 6% of replacement, so the replacement could be even accelerated.

But in a exponential scheme, the previous accumulated PV is not important, because the new numbers are to big compared to the previous.
And the exponential works for the depletion too, so instead of linear depletion or substitution, we would have some kind of gauss curve in the depletion.
We could expect 6-12% of maximun depletion in the curve when the oil drop fast.

A 12 drops means a 36% reduction for substitution. If that percentaje is not achieved then the future power would be constrained.

The numbers are complex.

And although we could expect that the PV EROEI goes up, the total numbers are very complex. In other replacements where complex things like synthetic fuels get involved, the factor of replacement could be greater than 1. It's possible that we needed even more power that compating to fossil fuels to create some things like cement.

So... I think that the renewable future is totally possible, but I remain concerned about the way and the timeline of the substitution.

P.D. I had to cut some text. Sorry

9. If I follow your reasoning, agrarian societies only had to build more windmills and they would have had as much energy as they wanted. I wonder why they didn't. Limited labor available? But isn't that always the case? Won't it always be the case?

On the other hand, if one man can, as it were, poke a hole in the ground and get a liquid out that does the work of thousands of men for years, labor becomes less of an issue, and you can do something like build an industrial civilization - until the liquid stops flowing of course.

1. Historic path. When we had the knowledge to use windmills to create electricity, we had fossil fuels available at low cost.

A agrarian society could build windmills but it need to reach a minimum level of knowledge to use it. How to create electricity to allow to melt metals and create more generators to create more electricity.

Before we know nothing about electromagnetism or thermodynamics, windmills could only be used for limited things like pump water, grinding grain or similar.

2. Fair enough. Suppose they somehow acquired that knowledge. It would no doubt be useful, but to what extent, I wonder, given today's resource situation (leaving aside climate change and population issues).

10. Hi oatleg,

I have considered your points. As a result of what you said, I wrote a small python program with some mathematical formulae and a logistic decline function. I wrote the python program because I don't think this issue could be solved analytically.

I will write a separate blog post addressing your points, but I'm very busy at the moment so it might not be soon.

Best,
-Tom S

11. > What matters is the AMOUNT of NET energy available to civilization, and that amount is far higher for renewables

Then why isn't Germany solar-powered, rather than coal-powered?

http://www.eia.gov/todayinenergy/detail.cfm?id=26372

1. Because Germany still has MORE coal-fired generation than renewable generation, regardless of ERoEI.

2. What do you mean "still has"? Germany, while pretending to transition to solar and wind by pouring subsidies into them, has been building new coal-fired power plants:

http://www.world-nuclear.org/information-library/country-profiles/countries-g-n/germany.aspx

If your claims were true, Germany wouldn't be building new coal. Something doesn't add up here.

3. "If your claims were true, Germany wouldn't be building new coal."

There are other reasons to build coal power plants, such as intermittency of renewables and not enough storage yet. It has nothing to do with ERoEI.

-Tom S

4. You said: "What matters is the AMOUNT of NET energy available to civilization, and that amount is far higher for renewables"

...So Germany should be transitioning to "renewables" (by which we all know you really mean wind/solar) -- especially since it has been paying and mandating to transition to wind/solar -- but it's not. Germany isn't getting any of its dispatchable power from wind/solar. We can see this by the fact that it hasn't reduced its coal consumption:

http://www.eia.gov/todayinenergy/detail.cfm?id=26372

We can also see this by the skyrocketing prices for electricity in Germany, and the increase in "energy poverty" (people cut off from the electrical grid) in Germany -- both cause by payments made for someth.ng (wini/solar) that isn't giving anything of vale in return. Apparently your claim was wrong.

> There are other reasons to build coal power plants, such as intermittency of renewables and not enough storage yet. It has nothing to do with ERoEI.

What if that weren't true? Germany/Denmark/Spain/Australia was the test. Wind/solar failed the test. It can't sustain itself. It can't provide the power needed to rebuild its own storage. It can't contribute to a modern society's energy needs in any way. Wind and solar are categorically unsustainable fuels. How many more tests do you need them to fail before you begin to suspect this yourself?

12. I suppose that Germany not only look at price but energy independence too.

Solar and Wind needs other sources of energy with dispatchable capability or energy storage.
Natural gas is today the most logical option, although we must be aware about batteries costs because droping prices could change the numbers.
But Germany imports natural gas mainly from Russia, and it had been some problems in the past with the reliability of the exports.
Mainly, Russia has blackmailed Germany sometimes in winter with fast changes in price and they stop the supply to force the negotiations.

Although coal and renewables don't mix very well, I suppose that Germany prefer to get enough power from coal or nuclear instead of complex negotiations about natural gas with Russia. In any case, any new coal plant is mainly for replacement of old units, not to have greater participation in the mix.

But they need to develop some kind of energy storage to allow high levels of renewable without use natural gas.

The reducing of renewable subsides is sawn by renewable detractors as a failure of renewable investment. I think that they are wrong. Germany is reducing subsides because the could install new renewables at less cost, and they don't want to grow the participation of renewable in the mix until the storage was developed.

1. > But they need to develop some kind of energy storage to allow high levels of renewable without use natural gas.

It exists. It's called "seawater uranium":

http://www.forbes.com/sites/jamesconca/2016/07/01/uranium-seawater-extraction-makes-nuclear-power-completely-renewable/

Over-unity-EROI storage of wind and solar isn't possible, and they can't possibly contribute in any way to any power grid:

http://bravenewclimate.com/2014/08/22/catch-22-of-energy-storage/

2. It has more risks. A coal plant is a lot more cheap than a nuclear plant.
The total cost could be similar. Nuclear has high costs of construction and dismantelation and long term disposal (pending of better technologies), but cheap fuel.
Coal has cheap plant, but it depends of how dirty is the plant and if you pay for the CO2 emitted. It has high externalities.

So, for nuclear to be competitive, it required that the plant goes alive its planned lifetime and better if it's extended until maintaining costs become too high.

If you are expecting that solar+wind+storage will become cheaper in the near future, nuclear plants are a bad bet. So I imagine that it's the case.
In fact, there is some troublesome data about higher than expected dismantle costs and there is a lot of nuclear plants that will be decommissioned soon.
In next decade, we will have more data about this costs and the progression of batteries, and it will decide a lot about the choices of post-2030 investment in energy.
By now, a lot of invesment prefers less risky investment. Solar and wind has the advantage of very predictable costs.
Fossil fuels has the advantage of lesser loss if the plant becomes not profitable and it should be closed before projected.
Nuclear plants are in a bad position for investment by now, an this explain why developed countries barely bet on it by now.

Very low EROEI of renewables is a myth. The lowest EROEI of solar, for example, that you can find is the (in)famous document about solar of Pedro Prieto and Charles Hall. But it's a study that accounts a lot of energy inputs that no other studies does. So it's really not a fair study for comparison (a lot of other sources would be <1 in the same conditions too).
In fact, it's not even EROEI but a new concept that they have called "EROEI extended".
And even in this study, mixed with data from 2008 up to 2011, they obtain >2 EROEI.

So... no, I don't eat the argument about low EROEI for renewable and high for nuclear.
It's seems very wrong to me because real costs are in the same order of magnitude, so EROEI must be similar too.

Batteries are the key piece that it is in development and the results are not sure.
As I said before, I will know about it in next years. But I can understand that investors are afraid in a 30-50 year investment on a nuclear plant when a better than expected development in batteries could become nuclear fission obsolete in less that the half of the lifetime.

3. Decommissioning and spent-fuel disposition are irrelevantly low costs for uranium:

http://world-nuclear.org/information-library/economic-aspects/economics-of-nuclear-power.aspx

Uranium reactor units don't absolutely need decommissioning. They can be kept running forever, or mothballed (google SAFSTOR). Decommissioning costs are higher for solar and wind than they are for uranium.

> real costs are in the same order of magnitude

No, they're not. We don't even know what the costs of 24/7/365 dispatchable solar and wind are, because they don't exist. You certainly can't say they're cheaper, when you don't even know what their costs are.

> Predictable

1 in 6,000 wind turbines goes up in flames every year. Predict which ones will burn. Will they be the ones that you invested in? Also, blades are thrown, mechanicals break down, and towers collapse:

http://www.caithnesswindfarms.co.uk/AccidentStatistics.htm

Besides that, they don't produce any dispatchable power, and therefore any prices you try to put on their "product" are bogus. Right now, we're looking at infinite amounts of money per unit of dispatchable power from solar and wind.

Developed countries don't invest in uranium because of regulation and a biased legal system that allows uranium to be sued for any amount of money when no harm has been done.

> Batteries are the key piece that it is in development

...Urban legend:

http://bravenewclimate.com/2014/08/22/catch-22-of-energy-storage/

If magical batteries could magically help wind/solar start pulling their own weight, they would help uranium even more. You can't win here.

High energy density can't be made obsolete by low energy density. It works the other way around. A society somehow powered solely by solar/wind would regress to, and never advance beyond, medieval, in every meaning of that term. Magical batteries wouldn't make any difference to that outcome.

4. Say that nuclear waste disposal is cheaper than solar and attack wind with arguments about burning turbines ensures me that you are not serius with your arguments.

In any case... anyone could make a fast check on some numbers about nuclear decommision declared by the industry.

https://en.wikipedia.org/wiki/Nuclear_decommissioning

Enough to see than, even declared number are SERIOUS. But when you check the total numbers of new proposed reactors and prices of electricity, like
https://en.wikipedia.org/wiki/Hinkley_Point_C_nuclear_power_station

Strike price at 2012 Prices - add inflation until Operating = £92.50/MWh or £120/MWh by time of operation

The prices are simply out of the market.

Anyone can notice that there is a abyss between the numbers of pronuclear organizations and real projects.

But even from this sources, there is a recognition of "near numbers" (always, of course, in favor of nuclear, in the same sense that prorenewable sources says the opposite).

For example, the same source that you linked, says that
http://www.world-nuclear.org/information-library/country-profiles/countries-a-f/china-nuclear-power.aspx

China says that nuclear prices for electricity is "0.43 per kWh (7 US cents/kWh)" while wind is "Wind cost to grid is CNY 0.49 - 0.61 per kWh"
2013 numbers. And from a state that externalize a lot of costs (like in coal) to population.
And with prices of renewable going down.

That explain why are western countries investment in nuclear so little. Too much risk of to be not competitive with renewable in the lifetime of the reactors.

About energy storage. If energy storage fails, the way of transportation of our actual civilization will fail.
Of course, I'm not pointing to doomerism about this topic. If storage failed, the civilization will push other alternative changes. Relocalization, demand managing, rebirth of big railroads using electricity, etc. etc.

But the thing is that if storage is enough to move a lot of electric cars and trucks, then there will be a lot of buffer demand to manage of electric net. Renewable and storage mix very well lowering the cost.

Another thing is the false assuption that the electric net needs "plain production". Electric net need to match demand and production. Nuclear is plain so you need storage or a "matching supply/demand technique" too.
Energy storage is only matching offer to demand. The opposite is possible too, and there is a lot of possibilities to create "moveable demand" to create a "virtual storage" by a fair price.

For example, railroad could reduce or grow freight traffic in parallel with excess or shortage of energy. It only means greater stocks and the prices could be very low.

Other examples are manufactures that stops in low energy seasons.

There is a lot of ideas to meet demand and supply.

The batteries are the most named because if batteries could match enough low prices, they could operate in worldwide scale and it could displace fossil fuels without any important changing in our way of living.
Without them, changes will be need in one way or another. Nothing apocaliptic, but enough to alter how some things work. Specially in transportation sector.

About "low energy density" it another ridiculous thing. A electricity cable transporting high voltage current is one of most powered thing that you can known.
A solar panel is a lot more energy dense than fossil fuel. In weight, in it's lifetime, a PV panel produce a lot more energy that it's weight in any chemical fuel known.
The low values of PV are "power density" not "energy density".
Of course this is a demostration about nonsense. That a panel or uranium has more energy density than coal means nothing about energy costs.
If you need more power or energy, you put more plants.

5. > with arguments about burning turbines ensures me that you are not serius

I'm confused by that. Why would pointing out the industry-acknowledged fact that 1 in 6,000 wind turbines burns each year lead you to conclude that I'm "not serious"?

> anyone could make a fast check on some numbers about nuclear decommision

...Especially since I posted a link for you. It's only one tenth of a cent per kWh -- and that's dispatchable power, something that wind and solar have never produced. Again, it's even lower if you extend the life of the reactor or put it into SAFSTOR.

> China says that nuclear prices for electricity is "0.43 per kWh (7 US cents/kWh)" while wind is

It doesn't matter what anyone pretends wind costs, because it isn't dispatchable, its cited costs normally don't include its required extra power transmission infrastructure, and its non-dispatchable power is energy subsidized such that it would cost even more if uranium/hydro/coal were displaced.

> Renewable and storage mix very well lowering the cost.

You're talking about a medieval society, in every meaning of that term.

> There is a lot of ideas to meet demand and supply.

...Uranium, hydro, and coal.

> batteries [...] could displace fossil fuels

No, they couldn't [...] unless you're talking about uranium as a battery.

> Without them, changes will be need in one way or another.

Nope -- not over the next 100 years.

> A solar panel is a lot more energy dense than fossil fuel.

A solar panel isn't a fuel. It's a mining rig. The ore it's mining is diffuse.

Uranium is cheaper than coal on an even playing field. That's because it's denser.

> If you need more power or energy, you put more plants.

...Then more people die:

http://www.caithnesswindfarms.co.uk/AccidentStatistics.htm

Is that what you want?

6. It is ridiculous because any problem it's integrated in the costs of REAL production.

The nuclear propaganda is that. Real projects are EXPENSIVE. Offer a closed prices of, x20 the price you said that it's reached and most countries will buy the project.
It's simply unrealistic, and that's the reason because real nuclear powerplants like I linked from UK says prices high over solar and wind energy.

I will not compete with propaganda links. The numbers of the real installation speaks by itself. Nuclear energy has only the advantage of historic production but the market it mostly depend from China plants to maintain global production. In the rest of the world it couldn't barely replace obsolete power.
The renewable is instead growing exponentially.

THAT's real data.
http://www.bp.com/content/dam/bp/pdf/energy-economics/statistical-review-2016/bp-statistical-review-of-world-energy-2016-full-report.pdf

Nuclear in 2014: 884.3 (MTep)
Nuclear in 2015: 892.9 (MTep)
Nuclear 2014-2015: +8,6 (MTep) (1%)

(wind, geothermal, solar, biomass and waste,)
Renewables in 2014: 316.6 (MTep)
Renewables in 2015: 364.9 (MTep)
Renewables 2014-2015: 48.3 (15,2%)

The fact is that in 2015, renewable has grown, not in relative but absolute numbers MORE energy (more than x5) than nuclear.

At this speed, renewable will surpass nuclear IN TOTAL PRODUCTION in seven years.

REAL NUMBERS, no propaganda.

"High energy density can't be made obsolete by low energy density. It works the other way around. A society somehow powered solely by solar/wind would regress to, and never advance beyond, medieval, in every meaning of that term. Magical batteries wouldn't make any difference to that outcome."

This is just totally wrong, in my opinion. Beyond a certain low level, energy density makes very little difference.

Energy density is important for transportation only, because cars and trucks must carry their fuel with them in a confined space. Even for that application, batteries are sometimes fine (for example, batteries can be used to power cars if you don't need to travel more than 200km or so).

When dealing with the power grid, energy density is almost totally unimportant unless the density is very, very low, far lower than batteries. Density would become a problem when we start running out of SPACE for batteries.

Let's say we want to use very low-density lead acid batteries for grid energy storage for the entire world. The world uses 1.4*10^17 watt-hours/year and lead acid batteries store about 100 Wh/liter. So we require 1.4*10^15 liters of lead acid batteries to store one year of electrcity. That works out to a cube 11 kilometers across, to store enough electricity for the entire world for a whole year, using the lowest density kind of battery that's in widespread use. Increasing the density would only reduce the size of the 11km cube. It would make no other difference.

-Tom S

8. "A society somehow powered solely by solar/wind would regress to, and never advance beyond, medieval, in every meaning of that term. Magical batteries wouldn't make any difference to that outcome."

We're definitely not going back to medieval times for this reason. Solar PV parks have a power density which is approximately 100x higher than medieval agriculture. Furthermore, there is more land available for solar panels and windmills because they can be used on land which is not suitable for agriculture.

I think renewables could provide a few hundred times more power worldwide than medieval agriculture did.

-Tom S

http://www.lowtechmagazine.com/2011/09/peat-and-coal-fossil-fuels-in-pre-industrial-times.html

Additionally, oats stored solar energy, and allowed it to be used on demand to power self-replicating draft animals. A solar panel sometimes produces power, and that power can't be released on command.

Solar panels would have to pay for replicating and repairing themselves, and their energy converters, and their energy storage devices, and the machines that run on their power.

Foregoing forest wood, peat, and coal, a society powered by nothing but wind and solar would be medieval at best.

> I think [wind and solar] could provide a few hundred times more power worldwide than medieval agriculture did.

...Then it's amazing there are no countries running on those fuels, despite massive efforts to achieve just that.

Your lead-acid battery would be 12 kilometers on a side, because the current global burn rate is about 20 terawatts. (It was 18 terawatts in 2013, and hasn't been at your assumed level of 16 terawatts for quite a while.) If it were limited to 25 centimeters high, it would cover the entire land area of the continental United States. It would need to be built and maintained, and people would die engaging in this activity. It would also self-discharge, so, at the end of a year, even if no energy were drawn from it, it still wouldn't hold much. It couldn't be a cube, of course, since it would crush itself and sink into the earth, but if it were it would melt and burn from the heat of charging and self-discharge, never-mind actually attempting to put it to use.

Density codes for safety. Trying to power society with solar panels and lead-acid batteries would make the world less safe and reduce life-expectancy to that of Medieval Europe, at best.

10. "Solar panels would have to pay for replicating and repairing themselves, and their energy converters, and their energy storage devices, and the machines that run on their power."

Sure. Since solar power has an ERoEI of greater than 9, even including storage, it could be used to replicate itself as easily as other forms of power.

I reached 11km because I rounded down twice during the calculation. It doesn't matter.

"It would need to be built and maintained, and people would die engaging in this activity."

So? People will die in every activity done on a worldwide scale. We accept certain risks.

"It would also self-discharge, so, at the end of a year, even if no energy were drawn from it, it still wouldn't hold much."

So? I was using a year as an implausibly large figure. The actual figure we would need for storage is probably about a week.

"It couldn't be a cube, of course, since it would crush itself and sink into the earth,"

I wasn't really suggesting that it should be a single large cube. That was to give a sense of the scale. If we assume that battery storage buildings are 100m high and the batteries are stacked on shelves with gaps between them for air circulation, and also assume that we actually require a week of storage, then the surface area required is less than 700 sq km. This is less than 0.005% of the land surface area of the planet--drastically less than is now taken by buildings or roads.

"Foregoing forest wood, peat, and coal, a society powered by nothing but wind and solar would be medieval at best.... Trying to power society with solar panels and lead-acid batteries would make the world less safe and reduce life-expectancy to that of Medieval Europe, at best."

That just doesn't follow at all. I don't see any reason to believe that.

11. > [solar] could be used to replicate itself as easily as other forms of power.

...Yet it isn't. There's no proof of concept. Maybe there's a fundamental reason for that.

>> It would need to be built and maintained, and people would die engaging in this activity."
> So? People will die in every activity

Per unit of dispatchable energy, more people die from a fuel that's more diffuse. If you want people to live longer than medieval life allows, you'll have to choose fuels that are denser than solar and wind.

A week's worth of lead-acid battery storage for the planet would cost \$2.5 quadrillion -- if paid for with today's fuels. Creating it with solar energy might not be possible, especially while attempting to stack it 100 meters high, but if it somehow were, the cost would be higher.

...And that's the problem with diffuse fuels. Everything gets more expensive.

The walls of these buildings, assuming they are concrete (which would be the best material for this application, since it's strong in compression, and this battery is heavy) would have to be pyramided so as not to explode from the load. This makes them take up more area. The buildings might have to look something like the Ultima tower:
http://www.tdrinc.com/images/photos/large/Towers04a1.jpg

...Except, only 100 meters high (instead of 2 miles high).

No concrete buildings, much less the fantastic buildings you are envisioning (fantastic because of the amount of mass they would be supporting), have been built with solar PV power. No lead-acid batteries have been built with solar PV power. No solar PV power-plants have been built with solar PV power. Maybe there's a good reason for that. Germany might have created the first proofs of concepts in these regards, but Germany never reduced its reliance on coal, despite investing heavily in solar and wind.

It's almost as if solar and wind are completely useless fuels.

12. "...Yet it isn't. There's no proof of concept [of solar replicating itself]. Maybe there's a fundamental reason for that."

There is no proof of concept of any form of energy replicating itself, except coal in the early 20th century. Nuclear plants are not built using the energy from other nuclear plants. Gas turbines are not transported into place using the energy from other gas turbines. That's because it's impossible or very costly to select only one fuel for all purposes when constructing something. It has nothing to do with renewables per se; it's true for ALL sources of energy.

"Per unit of dispatchable energy, more people die from a fuel that's more diffuse."

No, that's just not right at all. Energy density has nothing to do with the number of deaths. At present, coal burning plants in China kill 600x more people PER UNIT OF ENERGY than wind farms do (http://nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html), despite the higher energy density. It's because coal burning plants emit particulates which become lodged in the lungs of people nearby, causing lung disease and caridovascular disease. It has nothing to do with energy density.

"The walls of these buildings, assuming they are concrete (which would be the best material for this application, since it's strong in compression, and this battery is heavy) would have to be pyramided so as not to explode from the load."

The dimensions of the building are just not important. I'm giving those examples to provide a sense of scale. The buildings could be 5 meters high and would still take a negligible surface area. I'm certain it's possible to stack lead acid batteries 5 meters high, because I've seen them do it at the local auto parts store.

"If you want people to live longer than medieval life allows, you'll have to choose fuels that are denser than solar and wind."

I just don't see how you're arriving at that conclusion.

13. Proof of concept of uranium replicating itself is France, whose dispatchable electricity is over 75% uranium-fired and whose electricity cost is about half that of Germany and Denmark -- the latter two whom haven't been able to reduce their dependence on coal despite massive investments in wind and solar, which tells us solar and wind aren't contributing at all, but rather merely costing resources.

Further evidence that solar and wind can't self-replicate comes in the form of Agua Caliente, the world's largest Solar PV power plant. It cost \$36 billion per December 2014 gigawatt. Adding a week's worth of lead-acid battery storage would cost another \$126 billion/GW, for a grand total of \$162 billion/GW (which works out to \$2.03/kWh). That price is subsidized, of course, by uranium/hydro/coal. Take those away, and it wouldn't be possible to replicate Agua Caliente with 1-week battery storage.

Coal in China is used to produce dispatchable power. Wind isn't. Death rates per unit of dispatchable energy from wind are infinite. Making wind dispatchable would increase its death rates beyond what are seen for coal in China.

If a society beyond medieval could be powered by wind/solar, then Germany should have stopped burning coal by now. It hasn't. Germany hasn't even begun to reduce its coal consumption -- neither has Spain, neither has Denmark, and neither has Australia. The evidence of the failure of wind and solar to provide any relevant contribution to the power needs of modern societies is conspicuous.

13. Upppsss. Sorry.I copy the hydro data instead of nuclear. The numbers are even more near.

Nuclear 2014: 575.5 Mtep
Nuclear 2015: 583.1 Mtep
Nuclear 2014-2015: 7.6 Mtep (1,3%)

At this rate, renewable will surpass nuclear in 4,3 years.

http://www.bp.com/content/dam/bp/excel/energy-economics/statistical-review-2016/bp-statistical-review-of-world-energy-2016-workbook.xlsx

Here, we could see solar and wind detached.

Solar 2014: 43,2 MTep
Solar 2015: 57,3 MTep
Solar 2014-2015: 14,1 MTep (32,6% !!!)

Only solar has added more energy production than nuclear has added in the same year.

Wind 2014: 162,1 MToe
Wind 2015: 190,3 MToe
Wind 2014-2015: 28,2 MToe (17,4%)

Double than solar but it grows more slowly (less fast :).

14. > It is ridiculous because any problem it's integrated in the costs of REAL production.

You were talking about risk, not cost: "By now, a lot of invesment prefers less risky investment. Solar and wind has the advantage of very predictable costs."

Prove to me as a potential wind investor that my risk of wind turbine fire or blade throw or tower collapse or other mechanical failure is zero.

> real nuclear powerplants like I linked from UK says prices high over solar and wind energy.

Solar and wind aren't dispatchable, so their prices aren't comparable to those of the real fuels that really power society. But if you want to believe that solar and wind really are cheaper, then stop subsidizing them, and stop forcing them onto the grid.

> At this speed, renewable will surpass nuclear IN TOTAL PRODUCTION in seven years.

...And wind and solar still won't deliver any dispatchable power. Geothermal, biomass, and waste aren't wind and solar. Try to stay on topic. Seawater uranium is a renewable fuel, so you just said seawater uranium will surpass seawater uranium in total energy production, which is an absurdity.

1. "Prove to me as a potential wind investor that my risk of wind turbine fire or blade throw or tower collapse or other mechanical failure is zero."

Well, the risk of all nuclear plants melting down simultaneously isn't zero either. The risk isn't zero for anything. It's hard to see how solar panels will kill anyone but I'm sure it will happen to someone sooner or later ("He was sleeping beneath a solar panel array and an earthquake happened and the panels fell on him").

The risk to human health is negligible for both kinds of electricity generation (windmills and nuclear reactors).

"Solar and wind aren't dispatchable, so their prices aren't comparable to those of the real fuels that really power society."

Technically, nuclear reactors aren't dispatchable either. If we want to use them for load following then it would be very expensive. We'd still use natural gas fired plants for peaks during the day. It's less of a problem than for renewables but it still would be a problem.

-Tom S

15. The risk is not managed turbine by turbine, but in a park and with the needed insurance.

Your arguments are so evident to replay that I think that you are trolling.

You don't want to accept the reality. Solar and Wind not exists in a theorical world where compete with nuclear as is. Instead they exists in a world where it exists gas plants that could generate energy as you demand, pumped hydro, prices sometimes reflects the excess or lack of energy and demands adapt to it, etc. etc.
They don't need even batteries BY NOW. The need of the batteries is for compete WITH OIL AND COAL outside electricity production, like tranportation. And they are needed even if nuclear was used instead of renewable.

You can try to understand, or castle in rethoric and pronuclear links instead of accept the reality of the numbers (see BP data I posted).

If you accept the reality and the reasons behind that, we could speak reasonably about possible futures. For example, as I said before, what could happened if storage meets optimistic predictions or if not.
But if we assume one hypothesis, we must assume all the consecuences. The fail of energy storage it's the fail of the changing our current transportation system to a post-oil future.

Instead of rethoric and see a enemy in renewable, nuclear industry should see the real posible niches that they could fill. For example, because nuclear is based on heat, they could adapt this heat for direct use instead converting into electricity to convert it into heat again with great looses.
A great part of the coal industry is for melting metals, create cement and things like this where a preheating would be very helpfull.

But if nuclear industry loose their time fighting renewable in a market where they are loosing, they will become obsolete before they could adapt. Concentrated solar thermal could fill the niche too, although by now is more expensive. That is a window oportunity but it won't be open forever.

They are loosing their time trying unsuccessfully to block the competition instead to adapting to the new situation.

1. > The risk is [...] managed [...] with the needed insurance.

Double standard. Wind investors are getting wiped out by their failing turbines, by the way:

https://stopthesethings.com/2016/06/17/wind-power-investors-fleeced-teenage-turbines-falling-apart-in-donegal/

"the operations and maintenance cost of these things is around \$25 per MWh – hardly the zero marginal cost claimed by wind cultists"

> pumped hydro

http://bravenewclimate.com/2014/08/22/catch-22-of-energy-storage/

"hydroelectric capacity is not readily scaled up as it is restricted by suitable geography, a constraint that also applies to pumped hydro storage."

> The fail of energy storage it's the fail of the changing our current transportation system to a post-oil future.

Society doesn't run on oil energy, so you can go back to sleep. Every jet airliner that flies out of South Africa does so on natural gas (out of which is synthesized kerosene). The same would be true for the United States, except that that FAA hasn't approved it. Every ship could be fueled by uranium (and many already are). Every mining truck could by grid-powered via pantograph (and many already are). Uranium can power synthetic hydrocarbon fuel production, but wind and solar can't. This is because uranium can produce baseload power, and wind and solar can't. Wind and solar are absolutely useless for modern society. Only a medieval society, at best, could put them to use.

> Instead of rethoric and see a enemy in renewable, nuclear industry

Seawater uranium is a renewable fuel:

http://www.forbes.com/sites/jamesconca/2016/07/01/uranium-seawater-extraction-makes-nuclear-power-completely-renewable/

> because nuclear is based on heat, they could adapt this heat for direct use

Modern society runs on electricity, not heat. At some point in the future, data centers will be consuming more than 99% of the world's power. Heat won't be a relevant part of the energy market in the future. More and more, electricity is used to supply heat precisely when and where it's needed. Even in people's cars, electrically heated seats and steering wheels augment or even replace cabin heating. Industrial process heat is important, but even that's being replaced by electricity.

> A great part of the coal industry is for melting metals

The steel-making industry is going electric. It doesn't need heat anymore. It needs electricity.

> But if nuclear industry loose their time fighting renewable

Uranium has never fought wind and solar. Subsidies and mandates are forcing uranium off the grid. You're confusing wind and solar with subsidies and mandates.

> they will become obsolete

Diffuse fuels can't make dense fuels obsolete. People, however, can be killed by subsidies and mandates, regulations, and bogus lawsuits.

> Concentrated solar thermal

> They are [...] trying [...] to block the competition

Bullshit. Prove it.

2. "Every ship could be fueled by uranium (and many already are)."

I wonder what the cost would be to have nuclear powered commercial ships.

The US Navy went with nuclear propulsion for submarines because the energy density of batteries is so low, and there is so little space in a submarine for more batteries. The subs could only go full speed underwater for 6 hours or so. Obviously you can't burn diesel underwater or you'd suck up all the oxygen in the sub within a few minutes. That's why the US navy chose nuclear for submarines.

"Uranium can power synthetic hydrocarbon fuel production, but wind and solar can't. "

Sure they can. That's been done already.

-tw

16. You can repeat the same kind of links over and over. They will demostrate nothing.
You can search any problem on the wind and solar industry and shows every little problem that all industry has like it was something terrible that compromises the costs and the results.

Its a wastefull debate. The reality has demostrated the real costs, and the investors are chosen renewables.
The FUD about renewable doesn't work at this moment. The renewable industry has gone too far and it has build too many projects that demostrate the reality about all this propaganda.
Of course there is local problems and technical challenges. They are solvable and it's the reason because renewable energy do a lot of successful installations around the world.
I remember you the numbers. 7.6 Mtep of nuclear growth (in 2015) vs 48.3 Mtep renewable.

The FUD is not working.

I'm pretty sure about the fud of the industry throught things like this. Of course, blogs could be built only by fans of nuclear or renewable that has too much free time.
But articles in mass media life in forbes are paid.

In any case, as I said, i'm not interested in this propaganda battle, because it's not working.

I'm not a antinuclear person with special interests. I'm tired of bad data and industry costs socialization. If the nuclear industry could meet their own propaganda then they could offer cheap energy at a closed contract. When the countries demand to meet all the costs and assume the risks, the numbers drops the new powerplants proposals.

Personally I'm not focused on nuclear. Nuclear dreams are dropped by its own reality. I'm worried about fossil fuel replacement.

Oil: 4331,3 Mtoe
Natural Gas: 3135,2 Mtoe
Coal: 3839,9 Mtoe
Nuclear: 583,1 Mtoe
Hydro: 892,9 Mtoe
Renewable: 364,9 Mtoe

As you can see, I have very little interest about nuclear propaganda. We need to replace 90% of our source of energy based on fossil fuels.
That's the "enemy" (the exhaustion of our sources of energy and posibble collapse by bad planning).

Renewable has been growing very fast, so there is optimistic reason why we could expect that it will grow the percentage in the mix and lower the dependency of fossil fuels.

Nuclear, instead, has REDUCE the production. In 2006 it reached a peak of production of 635 Mtoe. Now it produce LESS. Only 583,1.

Perhaps the nuclear industry could make revolutionary new technologies and change the numbers with very cheap reactors. But I don't read anything remarkable in the nuclear fission world to expect this, and all fusion related are far from anything ready for production (even to create net energy in a steady way).

The numbers says me that nuclear will not drive the fossil fuel substitution.

As I said before, instead of spend time fighting renewables the nuclear industry should spend money in build profitable projects needed for this post-fossil future.

If they cannot compete with renewable in electricity prices, they could perhaps produce cheaper thermal energy or move mega transport ships.
They are not investing in trying new things.

1. Are you trying to say that seawater uranium is not a renewable fuel?

17. "Energy for investment is not scarce, because this planet is bombarded with 23,000 terawatt-years/year of solar radiation, which is vastly more than we will ever use."

You forget the word exergy. From a science viewpoint the story just goes like this: It is not energy what matters but exergy! How big will the exergy of this energy be? In the Sahara this might be very much for example. But if you want to use this heat there, than the exergy is nevertheless ZERO. There is nothing to utilize. Unless the North or South Pole lie there in the desert close to each other. In that case you have a thermal potential difference available by which an installation can deliver work. The basic knowledge stems among others from Carnot.

If you want to use the light of the sun in the Sahara, you probably can use about 10 to 15%. The rest wil get lost and becomes anergy, useless. For an electrical powerplant of 800 till 1000 MW you might have to use an area of 100 km2. You have allready moneylenders for this project? (See Vaclav Smil, Power Density)

1. Hi Hendrik,

"It is not energy what matters but exergy! How big will the exergy of this energy be? In the Sahara this might be very much for example. But if you want to use this heat there, than the exergy is nevertheless ZERO... The basic knowledge stems among others from Carnot."

I was referring to photovoltaics. When I said "solar radiation" I meant sunlight (photons), not background heat in the Sahara. Nobody suggests using the background heat in the Sahara to generate electricity.

"If you want to use the light of the sun in the Sahara, you probably can use about 10 to 15%."

Yes, which is why I used the conservative figure of only converting 1% of incoming sunlight to electricity, which is what I stated in the article. Solar panels would be ~15% efficient, and there would be space between the panels, and only deserts would ever be covered in solar panels, and so on.

-Tom S

18. PV. Level of utility is ww almost zero. How come?
If I was you, I would read prof. Dietrich Pelte, Vaclav Smil and Charles Hall. Just to begin with.

1. "PV. Level of utility is ww almost zero. How come?"

Because PV has only become price competitive in the last few years, because of rapid technological improvements and price decreases.

The level of PV deployment is not "almost zero". PV worldwide now represents 250 GW, which is approximately equivalent to 60 GW of coal or nuclear generation if we adjust for PV's lower capacity factor. In other words, PV is now equivalent to 60 1GW nuclear power plants, starting from a base of nearly zero in 2009. That is considerable, not "almost zero".

"If I was you, I would read prof. Smil... Hall..."

If I were you, I would read other net energy researchers, other than just prof Hall. There are more credible researchers who have looked at the EROI of renewables (for example, the National Renewable Energy Laboratory) and have reached conclusions very different from his. Here is some more information: http://www.nrel.gov/docs/fy04osti/35489.pdf

You should also start asking why various conclusions are only held within a tiny fringe group and have not convinced any of the relevant domain experts. Why do you only hear about this stuff from within this tiny fringe group?

As for Dr Smil, I have already read him. Are you aware that he wrote an essay in which he referred to peak oil doomers as a "catastrophist cult" or something like that? Did you read that part?

Henrik, do you have any objection to any point made in the article? If not, then saying things like "If I were you..." or "you already have moneylenders for this project?" (as if solar projects depend on me personally raising the money) is just fake confidence and dodging the issue. I have made a straightforward argument here about a mistaken theory. If you have no objection to any of the material in the article, then the point stands.

-Tom S

19. My critique is on your statement of abundance! Bountifulenergy. Oh, there is the sun, there is the earth and lots of lots of energy available. It is nonsense in a fossil free society I told you. Maybe you don't like the outcome of the stuff Charles Hall is studying but I like his perspective: …..why in the world is economics taught and undertaken today as (only) a social science rather than as a biophysical science? If you want to argue, argue with him, I'm only a second league player in these questions. But an economist in the classical sense also belongs to this league I guess.

Debating on energy, I would take another start. Start first with with agriculture, I must say that's my expertize, there seems no abundance there. Smil is sympathetic to billions of people who can live because of the Haber/Bosch machines (is fossil fuel driven). Without HB billions would die. If you look to the future (also science can make a wild guess) I suppose there are billions less than Smil's math who can live from the land only. Nature does not simply have enough N. (EROI in agro historical perspective is a interesting story.)
And then you have P. If I was an American I would reread Isaac Asimov again and again. In 1959 he already wrote an article on "P: Life's Bottleneck. You missed it? President Roosevelt already knew! You can't help the majority of your country voted for a fool. He also missed Asimov's "No more ice ages? 1959, for sure! Please also don't listen to the organics who tell us there is abundance in agriculture, there is not without fossil fuel. And if you would have read all Smil's work, what a job, then you would know of this kindergarten science (Smil's words).

According to IEA the States have 1,3% of the total primary energy supply geothermal/solar/wind. My country not yet 1%, Gemany not yet 3%. (And don't listen to what the Fraunhofer institute tells you.) Is it all a classical economic question? I doubt. Togather with Hall, he has a new book on this theme, read Smil's book on Power Density. The power density is low, very low of all these green solutions. That's why Evert du Marchie van Voorthuysen (gezen.nl) focussed on CSP. Read what Smil says. Also here there is no land of milk and honey, no abundance. The people of the car industry they are not crazy, that's why Audi started just across the border a Power to Gas experiment. They dearly need green fuels. Where do you want to leave all those windmills I asked. Nowhere. The windmills in the North-Sea have already other customers.

Did I read Smil? Yes, several books on this theme. Did I hear what Smil said? Yes I heard. He also promotes the Diesel. Before the debate on this theme went sick. He probably did not know that an modern egr diesel cannot lower his NOX's whithout getting more soot, less power and a much higher fuel comsumption, thus higher CO2. But he knows now. So even Mr. Smil can make mistakes. Maybe he will say now that we have to accept some evil. Obvious lots of people do not want to accept this and admire paradise.

ERoEI is a useless figure?! Just ask Dutch Shell if they agree with you. I know the answer. Strange statement for an economist.

Hendrik J. Kaput

1. Hi Hendrik,

"Maybe you don't like the outcome of the stuff Charles Hall is studying but I like his perspective"

It's not that I don't like his outcome. He is making mathematical errors (in my opinion) and his views are discrepant from those of other researchers in the field. The expert consensus is clearly that the EROI of renewables is fine.

"Start first with with agriculture, I must say that's my expertize, there seems no abundance there. Smil is sympathetic to billions of people who can live because of the Haber/Bosch machines (is fossil fuel driven). Without HB billions would die."

I grant that the Haber Bosch process is crucial, but it does not require fossil fuels. HB can use hydrogen obtained from the electrolysis of seawater, and this was very widespread in the past. Right now, natural gas is used to obtain hydrogen because its cheaper, but electrolysis can also be used, which requires only electricity and seawater.

The chemical formula for Ammonia is NH3. It does not have any carbon atoms in it. It does not require fossil fuels.

"And then you have P. If I was an American I would reread Isaac Asimov again and again. In 1959 he already wrote an article on "P: Life's Bottleneck.""

The most recent estimates from the USGS indicate that P is not in short supply for the foreseeable future. It is not in short supply, for at least centuries. If the price of P increased then it would become economically feasible to do things like recycle sewage, recycle laundry water, and so on.

Eventually, the availability of P would become a problem with a very large population, but it's not clear that will ever happen because of a demographic transition already underway.

I used to have an article here dealing solely with P but I removed it. However, I do address the issue somewhat in the article "We are not running out of resources".

"ERoEI is a useless figure?! Just ask Dutch Shell if they agree with you. I know the answer."

I don't think ERoEI is totally useless. I think it's useless by itself. It can be useful as an intermediate figure to calculate other things, and of course it matters if ERoEI is below 1. However, all common sources of electricity have sufficiently high ERoEI that little energy is required to obtain energy, so the differences in ERoEI just don't matter very much.

Insofar as I understand, Dutch Shell and other energy companies do not make decisions based upon ERoEI. Nobody in industry even bothers to track that figure. They make decisions based upon monetary costs, which is why they have elaborate accounting procedures for tracking money but not for tracking net energy.

"The power density is low, very low of all these green solutions."

Sure, but that doesn't matter much for PV. That would affect the amount of space taken for the panels, which is negligible compared to the surface of the earth.

"But an economist in the classical sense also belongs to this league I guess."

I should point out that I'm not an economist, but a student.

By the way, I appreciate that you're addressing the content here. I'm definitely not trying to take a polyanna view and dismiss serious problems the world has, such as global warming or environmental degradation. However, the belief about "running out" of things like energy or minerals, which would cause a disruption of civilization, is just mistaken, in my opinion.

-Tom S

2. Henrik and Tom:

Phosphorus is indefinitely recyclable (as implied above by Tom). If the Earth's crust contains an average abundance of 1,050 ppm phosphorus, and if the Earth's crust masses 2.77e22 kg, then it contains 29.1 quadrillion tonnes of phosphorus. If the average human could thrive while containing an average of 700 grams of phosphorus, then the phosphorus in the crust would be enough to sustain 41.6 quintillion humans simultaneously.
https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust

The story is similar for all the other elements people's bodies need, except one: nitrogen. There's only enough of that in the earth's atmosphere for 2 quintillion thriving human bodies, and that would leave none left over for use as an atmospheric buffer gas.

Regarding Haber-Bosch, the first synthetic nitrogen fertilizer was produced without fossil fuels, and with the energy from a hydroelectric dam. Today, there are still examples of hydroelectric dams producing the energy for production of synthetic nitrogen fertilizer. This information is readily available on the peakoildebunked blog:
http://peakoildebunked.blogspot.com/2007/11/314-peak-oil-and-fertilizer-no-problem.html

"A week after meeting, Eyde and Birkeland submitted a patent for artificial fertilizer. They obtained money from the Swedish financiers, the Wallenbergs, and a mere three years later a hydroelectric plant had been built out of the wilderness at Notodden and a Birkeland-Eyde arc furnace was producing the first Norgesalpeter - Norwegian Saltpeter, i.e. calcium nitrate."

3. Thanks for the info, hitssquad.

"If the Earth's crust contains an average abundance of 1,050 ppm phosphorus,"

I wonder if it would be feasible (both economically and energetically) to mine phosphorus from soils that contain it at a concentration no higher than the average concentration is now. The reason I ask, is because any kind of recycling scheme will be imperfect, and some P will just end up on the ground or in the Oceans. Over millennia, the P in the earth would become more evenly dispersed as a consequence of our mining and then disposing of it, even if we recycle. Recycling would just slow down the rate at which this is happening.

If we are able to recycle (say) 70% of P from laundry and sewage, etc, then would it be possible to mine the remaining 30% from low-concentration sources? If so, then we have enough P indefinitely.

Of course we have more than enough indefinitely for all the other elements we need (iron and carbon for steel, silicon for glass, calcium for cement, nitrogen and hydrogen for ammonia, etc). P is the only real bottleneck, and it's not clear that it will ever be an actual bottleneck. The answer depends upon whether it's feasible to mine it from lower-concentration sources.

-Tom S