Analysis: energy storage cannot solve the problem of intermittency of wind or solar power

solar-and-wind-energyClimate Skeptics often cite the fact that renewables like wind and solar don’t have constant power flow, and thus need either a nuclear, hyrdo, or coal/gas power plant backup in order to deliver a reliable power supply to the electrical grid.  Proponents often retort with “all we need is better battery technology to store power”.

The Catch-22 of Energy Storage (h/t to WUWT reader Greg in Tips and Notes)

Pick up a research paper on battery technology, fuel cells, energy storage technologies or any of the advanced materials science used in these fields, and you will likely find somewhere in the introductory paragraphs a throwaway line about its application to the storage of renewable energy.  Energy storage makes sense for enabling a transition away from fossil fuels to more intermittent sources like wind and solar, and the storage problem presents a meaningful challenge for chemists and materials scientists… Or does it?

Several recent analyses of the inputs to our energy systems indicate that, against expectations, energy storage cannot solve the problem of intermittency of wind or solar power. Not for reasons of technical performance, cost, or storage capacity, but for something more intractable: there is not enough surplus energy left over after construction of the generators and the storage system to power our present civilization.

In particular, we can’t use batteries or chemical energy storage systems, as they would lead to much worse figures than those presented by Weißbach et al.  Hydroelectricity is the only renewable power source that is unambiguously viable.  However, hydroelectric capacity is not readily scaled up as it is restricted by suitable geography, a constraint that also applies to pumped hydro storage.

More here by Barry Brook –


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more soylent green!

I think you misspelled analysis — “Alanysis”

Dr. Bob

One only need look at efficiencies for conversion of electric power into a storable form of energy. California is mandating storage and one project is to use pneumatic storage. Compressing air causes heat, which is lost to the system. Running an air turbine to generate power is not very efficient. If compression of air for storage (without any leaks) is 50% energy efficient, and regenerating electricity from compressed air is 30% efficient, the net is 15% efficiency. So you need 7 times the power generation to store that power that would be directly consumed without storage. Such a waste of resources, not to mention the wildlife killed by these “renewable” devices.


Yep. That little thing called entropy that the Climateers ignore. All conversions are 100%efficient they think. unfortunately the real qworld says different.


We missed this new technology, already in use.
You can only generate electricity (from solar panels or wind) within your own power-grid substation! You cannot transform up into the HT grid! Hawaii is a classic case in this story, they stopped installation of solar panels, as they supply a lot during sunny parts of the day, when low off take is the case, and less when everybody comes home in the evening. But this “battery” could solve it.


why on earth would Hawaii need anything but GEOTHERMAL !!!

They won’t like to hear that. Let the squirming begin. 🙂


A pumped storage system may work where there is a large elevation differential…Dig 20 small (?) reservoirs cascading one into another, with 20 motor-generator set-ups ….
A pilot set up could be done on Maui as there is a 10,000 foot elevation gain over a few miles…Getting permits to dig mother Maui is another matter…

Just by coincidence I did a page with pumped storage cost estimates. It was a back of the envelope job using a simple spreadsheet…I don’t like to plug what I do but I got tired of the unsupported statements about wind power and its intermittency problem.

Anthony Watts,
I think that your analysis is correct.

It’s simple math – the wind can die down for long periods of time – far beyond the storage capacity’s ability to make up for the missing power. And how is that storage capacity going to be replenished once the wind reappears and is needed for current demand? The pumped storage facilities that California is building in the mountains (less than a dozen I believe) cost quite a lot – over half the cost of a nuclear reactor of equal output capacity (around 1000 megawatts) – several billion dollars each. Their storage capacity is but 12 hours or so of max output. Their usefulness is in their ability to shift renewable capacity from time of “harvesting” to time of needed demand – a matter of hours, not days. It avoids having to throw away energy collected by the solar panels/wind turbines during slack demand periods during the day. I believe the loss due to storage is on the order of 25%, quite a bit.


Zactly. How long of a period of no supply can you prepare for? A day? Three? Doldrums could last for weeks. The finite limits to storage mean you can’t use it to fully back up WT/PV.
Another point I have made before. As you create storage to extend WT/PV, you further erode the financial case for conventional backup. No one is going to build and/or operate a power plant that is only going to run a few days a year.

Part of the problem is the use of land and water to generate energy. Where are the analyses of the water and land requirements per KWH? That is one of the biggest problems with ethanol, by the way. It takes a lot of water to grow the corn to make the ethanol. The land and water should be costed out for all the different generation systems.
We have no 100% reversible energy storage systems, and will not for the forseeable future. Unless you go to Heinlein, that is.
The chief renewable energy source remains the Sun. And solar power through solar cells is hideously inefficient. Plants do a lot better.
Anyway, you can now burn or decapitate as many eagles as you want, if you produce renewable energy. So much for endangered species!

george e. smith

“””””…..The chief renewable energy source remains the Sun. And solar power through solar cells is hideously inefficient. Plants do a lot better……”””””
So the present record for conversion efficiency from sea level solar radiant energy, to electricity (DC) by solar cells, is about 43.5 % Incident solar watt/m^2 to DC electric power Watt/m^2.
You say “”..Plants do a lot better..””
Could you give us your numbers for just one example of plant conversion of solar radiant energy. to any other human usable form of energy, that you say is a lot better thn solar cells ??


The Weissbach paper is concerned with EROEI (energy return on energy invested ) values for different power generation technologies : renewables, fossil fuel , hydro and nuclear .
A significant surplus of energy over that used in the construction in the plant is required to maintain the quality of life presently enjoyed in US and Europe. Weissbach gives a minimum value of 7 , which is comfortably exceeded by conventional power sources at present , but a combined plant of , say ,photovoltaic solar , with energy storage falls to about 3 . Wind with storage is marginal, 9.
To my simple mind it appears that Weissbach is saying that you cannot have a predominantly “green ” way of life with renewables as your main source of power and at the same time expect to have all the same facilities that we have come to expect, eg pensions, health care , libraries and highway maintenance to name a few at random.
As even some conventional sources of power such as oil become more expensive to exploit the EROEI figure falls. This is not just an academic debate . It is of important contemporary relevance in the UK given the role of easily extractable oil in the economy of a future independent Scotland .

There won’t be easily extractable oil in Great Britain or any of its parts, independent or not.


Perhaps they cannot completely ameliorate the problem, but they can go a long, long way towards ameliorating the problem, especially in the temperature zones through the tropics.
Look, solar power isn’t a crazy option now, with nothing like cheap big storage. If one invented sufficiently cheap, sufficiently big, storage — say, something with the energy density of gasoline (hey, I’m just presenting a counter argument and can hence invent any sort of science fiction I like) that costs less than existing car batteries by a factor of five — solar still wouldn’t work too well for Finland or Antarctica, but it would be gangbusters awesome here in NC. Electric cars would actually become economically feasible and not a horrendous cost-benefit fail. Just using the batteries to buffer ordinary power sources so that they could generate in off-peak and deliver in peak would drop power prices and eke out fuel supplies for all kinds of power.
So let’s not go all crazy and say that better batteries don’t matter. They matter a lot. They matter a lot for a lot of things. One of the many things they matter a lot for is to transform things like solar and wind power into sources that actually could provide most of our energy needs, with fuel based power only as a comparatively rarely used bridge or a primary resource in the high temperate and arctic winter.
Outside of that, the top article seems to assume that we are trying to build a society based only on solar and wind, and I don’t think that is the case. At least, it isn’t the case for rational, sane people. Maybe it is what Greenpeace nuts would like, if they don’t live in Oulu or Greenland or Alaska.

Excellent comment as usual. Thanks, rgb. Technology has a habit of breaking through to feasibility after a period of serial unimpressiveness, and I don’t see why this should be any different. And it often involves some innovative lateral thinking. Martin 457 (August 26, 2014 at 5:37 pm) makes such a point – instead of trying to store excess power, find ways to use it.

A C Osborn

The problem is every time you add something to the generation, charging a battery, pumping water etc you are “loosing Energy” to efficiency, it doesn’t matter what system it is.
That energy is wasted and not retrievable and as this article shows reduces the overall efficiency of the system, which is already crap compared to Fossil Fuels or Nuclear.


The efficiency you are looking for is not thermodynamic efficiency, it is economic efficiency. Coal, Gas, Nuclear cost money for fuel. Over time, the amortized cost of a solar cell/battery system that you buy once and then produce energy at whatever efficiency from for free for the rest of its lifetime may, or may not, end up cost competitive with (your share of) the amortized cost of the coal, gas, nuclear plant, the distribution hardware, the fuel, plus the profit (of course) of those that own it and sell you the power as they de facto rent you the hardware. If the electricity you produce and/or store comes at an amortized cost per kW-hr that is less than what you pay for electricity from your power utility, it is economically a win.
If you start looking at energy efficiency, bear in mind that fuel based sources are typically only around 30% efficient thermodynamically, and then you lose more to transportation — the power lines over head heat up as they deliver power to you and you pay for that loss as well as the power you actually use. The same issues are true for cars — electric motors are comparatively efficient compared to the heat engine efficiency of the gasoline motor.
We could synthesize sugar directly out of air, water, and carbon dioxide (plus energy). Or, we can plant a tree. The tree may or may not be a particularly efficient way to make sugar — indeed, we will probably have to still use organic chemistry to break up the starches and cellulose to get much sugar out of most trees — but it makes complex carbohydrates for free as long as it is planted in the free sun, exposed to the free air, and watered (for free) by sufficient rain. We might even be able to use bacteria or yeasts for free to turn the starches and cellulose into sugar, or alcohol, or whatever, much more cheaply than we could synthesize the molecules directly from raw materials. Again, it is overall cost efficiency that counts, not thermodynamic or chemical efficiency.

CC Squid

1. Solar panels have a limited use period which I have heard is about 25 years max.
2. Mirrors used to direct sunlight to a hot water boiler burn down birds. I assume you have read the article on “streamers”.
3. Wind mills are dying because of inferior bearing technology used in their manufacture. The only have a limited life of twenty years even if the bearings were the best that could be manufactured. They also kill eagles.
From your responses I assume that you must make a living from one of the above products. Would you care to mention the technology that you work with?
So let’s talked about pumped storage. This would be very useful on the west coast but I challenge you to answer the following questions.
1. Does the pumped water from the Pacific to the dam require that the water be desalinated first?
2. If you are going to use fresh water, are you going to pump it from aquifers?
3. If you are going to use water from the rivers will the environmentalists allow that.

Gee, squid, why are you implying Dr RBG is ’employed” by a company in the energy production or energy transmission fields? Do you WANT to suspect that he is in the “evil” energy production business from fossil fuels, or is it easier to believe that only “clean and holy” renewables industry employees are innocent and correct in their beliefs about global warming and actual energy production?
Hmmmn. Essentially all global warming funding for research, for building renewable energy systems, and for renewable energy travel, taxes, licenses, and promotion at conferences and universities is from federal and state governments, which have an explicit interst in the 1.3 trillion dollars of revenues and taxes that only continued CAGW propaganda will generate each year.
What federal employees and what federal government bureaucracy do you believe is worthy of such trust and confidence, is completely honest and moral, is completely trustworthy and will be focused only on the actual science?
Or are they the fund-seeking, lying bombastic hypocrites and propagandists like Hansen, Gore, Mann, Holdren, Obama, Clinton that we have now seen for twenty years? I see nothing in any CAGW propaganda that indicates anything but corruption, greed, immorality and and grasping for absolute power behind it.


Check out a little company called Aquion (or maybe it’s spelled “Aqueon”). They’re working on a battery based on cotton and salt water. It certainly **won’t** have anything like the energy density you’d want for mobile applications. But it may well be cheap enough for utility-scale use.
A few months ago, one of their engineers did a BotE estimate that they could profitably sell units that would give 24-hour backup for a single house at a price of about $10k. That’s less than a factor of 2 away from making economic sense just for use in a charge it up off-peak and run off batteries during peak scenario. And that $10k-ish price was based on their current prototype fab line, without assuming any economies of scale from going to full production.
Their approach doesn’t give great energy density, but it’s cheap, safe, and avoids exotic (expensive, dangerous) materials. And did I mention CHEAP?

Unfortunately, we’ve been using and trying to develop new batteries for decades. While technology has evolved somewhat, I’m not convinced we’ve come anywhere near the breakthroughs we need to truly make solar and wind fully cost-effective and realistic. Others also make this point below, and I have a longer post at the bottom…


Liquid Fluoride Thorium Reactors. Problem solved.


Or will be, when all the problems with LFTRs are solved. I don’t really disagree, but the assertion that LFTR is already ready for prime time is at least arguable — there are still engineering issues that haven’t really been solved as in demonstrated in a functional, scalable prototype. We’ll see what happens to the various medium to large scale pilots underway.


The article is a good one, but even this article is very slightly off the mark. Few seem to realize it, but we do not actually “consume” energy. By the 1st law of Thermodynamics, energy is neither created nor destroyed. The thing that we are consuming is neg-entropy, the “orderliness” of the energy. We use up the orderliness to push forward our various human aims. This is another way of saying that we extract value (orderliness) from the energy as we convert the energy from a relatively low entropy state to a higher entropy state.
This fact is highly relevant to the energy debate, because different sources of energy BEGIN with widely different levels of neg-entropy, and further processing is ALWAYS in the direction of increasing entropy. That is the meaning of the 2nd law of thermodynamics.
Hence, it is inherently more difficult to use dispersed and thus high-entropy energy sources. It will always become progressively harder to extract net order from the process as the dis-order of the original source rises, and all of the proposed renewables except hydroelectric are inherently high entropy.
It is quite inevitable that nuclear will be the hands down winner in the EROI sweepstakes, given its extraordinarily concentrated (high neg-entropy) nature. Recall that in the 1950s it was projected that nuclear energy would be “too cheap to meter” and at the thermodynamic level that still should be true. The only reason it is not true today is that meeting all of the environmental and safety regulations forms the bulk of the cost.


And of course, the cheapest source of nuclear power is — Mr. Sun! By landslide, actually. We are, after all, solar powered entities living in a world that is almost entirely solar powered.
That’s the beauty of solar power. The sun won’t run out of fuel for a few billion years yet (by which time We Will Not Care — although perhaps our heavily evolved cockroach descendants will, if solar evolution and/or humans haven’t rendered the planet uninhabitable in the meantime). It delivers an average of a few hundred watts/m^2 to Earth every day, whether or not we do anything with the energy other than let it warm things or be used by plants. Solar cells are merely cups we hold into the never-ending waterfall to get the occasional drink, as opposed to burning raw hydrogen and oxygen and waiting for the resulting water to cool, badly metaphorically speaking.
As I pointed out above, thermodynamic efficiency, while not irrelevant to the discussion, is not the critical quantity of interest. Economic efficiency is all that matters. Cheap (enough) solar cells and cheap (enough) large (enough) batteries and maybe cheap (enough) long range energy transmission facilities can easily amortize out to be cheaper than the similarly amortized cost of fuel-based power generation, reliably delivered, per kW-hour. And that is really all that matters.
Solar is already cheap enough to make amortized sense in many parts of the world, with or without subsidy. Research and technical development continues to further drop the installed, amortized cost per kW-hour and to address weaknesses, like the lack of production at night, with things like cheap (enough) large (enough) storage, or like the fact that inside the arctic circle, “night” can last for days to months and solar is inefficient down to well into the temperate zone winter for months at a time, with things like cheap (enough) long range (enough) transmission facilities.
Let me put a few hundred million joules into a battery the size of a beer can and weighing 1 kg for $10 retail, let me build a high-current room-temperature superconductor out of copper oxide and graphite sheets for $0.10/meter capable of carrying a million amps or so, and solar can and will power the world forever, at no greater cell efficiency than we have already. It would be an absolute no-brainer, in fact — the world’s tropical deserts would generate and store energy that would be piped all over the world, for infinitely less money than burning stuff to make electricity.
A beer can like that would even make gasoline engines obsolete. Indeed, it might marginalize even fusion, should we ever work out (literally) the magnetohydrodynamic kinks of confining a plasma at fusion conditions without touching it in ways that actually produce more energy than the confinement/ignition consumes. 100 kg of car battery would actually store as much energy — say 10 gigajoules — than 80 gallons of gasoline, and that energy would be accessible at 2-3 times the efficiency of the gasoline, making it more like the equivalent of 160 gallons (say). An electric car with 100 kg of battery (costing $1000) would actually run for as much as 5000 miles — say, half a year of driving — between charges.
The point being that one cannot possibly say that batteries won’t ever make solar a viable energy resource to power human civilization. On the contrary, cheap enough, mass dense enough energy storage would instantly make solar the only (economically) viable means of producing energy. One could conceivably afford to ship energy around the country in the form of fully charged batteries mounted on train cars or (electrically powered) semis.
Heinlein “invented” batteries like this a long time ago. His estate funds a prize:
because this is also a key component of feasible space exploration and exploitation. It is worth noting that Heinlein also “foresaw” infinite corporate greed and profit taking for the company that invented shipstones, simply because an inexpensive, high density, high capacity storage battery is worth its weight in gold, or very nearly so. Almost literally. Just the recent developments in lithium-ion batteries could extend laptop lifetime to a day (and the battery lifetime itself by years), possibly even affordably. And this isn’t the only technology being explored, or necessarily the long term winner. Zinc-oxide batteries have (forever) show enormous promise, if anyone ever figures out how to resolve the deal-killers in the engineering. And we haven’t properly begun to fully explore the range of possibilities enabled by new nanotechnology, resolving problems of this sort at the sub-micron scale.


I concur with the duke bat guy. Reducing the conversation to the most easily understand and most widely used terms means talking about economic efficiency. Note, we’re not talking about “filthy lucre” here, we’re just saying that economics, the dollar, is the unit of measure that takes into account all the relevant variables, including energy / thermodynamic efficiency. It’s baked in.
On a different note, whereas I agree that solar is free (by any meaningful definition), the collection of it is not. It’s fun to imagine a world where we carpet the deserts in solar gathering devices and push an electrical current ’round the world in low temp, low loss super-conductors, but all that infrastructure will cost us dearly – both to install, and to maintain. This is not to say we won’t drastically cut the costs of the technology, or that we shouldn’t do this. I’m merely pointing out that claims about future “cheapness” should be taken with a big grain of salt. (Why salt? I’ve always wondered this.) We bought this already with the promise of nukes “to cheap to meter” as noted above. It turns out, however, that it takes a lot of work to maintain the structural integrity, and efficiency, of components subjected (non-stop for 18 – 24 months at time) to really really high temps, pressures, and radiation levels. Of course those specific challenges won’t exist in the solar-desert-utopia, but some other challenges are sure to crop up.
Finally, as implied/noted above, very cheap solar energy is available to us currently…in the form of coal, oil, and gas. We’re reaping the benefits of letting the earth’s natural forces do the work of condensing solar energy into usable resources.


That’s the beauty of solar power… It delivers an average of a few hundred watts/m^2 to Earth every day, whether or not we do anything with the energy other than let it warm things or be used by plants.

As we are constantly told, a change of ~3 watts/m^2 out of the 1360 that hits the planet is sufficient to cause catastrophic global climate change. Works as well if that change is down as if it is up. Unless we let it warm things, we will all freeze to death. Unless we let it be used by plants, we will starve to death – provided that we don’t all die from lack of oxygen first. So, you really cant use any of that couple hundred watts. If you do, we all will surely die.

Joe Crawford

This is an excellent article. It is about time someone actually looked at renewables from a systems approach. However, I would have thought that this sort of analysis would have been common in the energy sector for a long time. But, as with most unique discoveries in engineering, once made everyone wonders why it wasn’t there all the time. Of course selling the idea to the true believers
in ‘carbon pollution’ is going to be a problem. I question whether they will have either the math, logic or science background to understand it (i.e., anything over maybe third grade).
It appears to me that one of the objectives of those pushing for renewables is to get everyone use to the intermittent availability of electricity. Once you’ve accomplished that it should be easy to totally eliminate use of all so called ‘fossil’ fuels. Once that is accomplished I imagine there will be a rather interesting tussle for control of the power switch.

I have lived in quite a few locations with interruptible power (I think the concept was invented in either Argentina or Congo). The concept looks fine until you realize everything breaks down all the time due to power surges.


The electronics industry has gone from computers that would do one operation a second to the powerful systems we have on our desk in a period of about 80 years. Rechargeable batteries have been round for over 120 years and have seen an increase in capacity of a few times that of the early batteries. The reason is because battery chemistry has been known and understood for a long time and there is a very real limit on how much power a battery can hold. It is wishful thinking to believe we will see a huge gain in battery capacity in the near future. Until a solution to storing power is found, constructing wind and solar systems is a waste of money.

richard verney

My dad had an electric car in the early 1990s. It was a novelty at the time. When he went into town and parked it outside the shops, one of the shops would run an electric cable so he could recharge it whilst he was shopping (it would not be done today because of health & safety and fears of pedestrians tripping over the cable). If he went to a restaurant, the restaurant would run a cable to the car park so he could charge it whilst dining etc. This was really necessary since although it had a range of about 120 miles and a top speed of about 50 mph, after 20 or so miles there was a noticeable fall off in performance. My dad lived in a hilly area, and in the winter, at night, when it rained etc, there was a big demand on the batteries.
My dad use to tell me that there had been no significant improvement over the electric vehicles used in the 1930s for the reasons that you suggest. In the 1930s a lot of electric vehicles were used for delivery in high density delivery situations. The milk float is one such example where the vehicle would stop off outside every few houses deliver the milk, drive down the road say 6 or 7 houses and stop off and deliver the milk, repeating the porcess.
There have been no really fundamental improvements in battery design because of what you said. My dad told me exactly the same. The technology is old hat and well understood.
This also applies to wind. The technology behind generators has been well known for more than 150 years. The technology behind efficient propellors has been known and honed in the 1920s to 1950s. There is no magic wand that will greatly improve the power output from wind turbines because we already know the basic principles. The only way to make a quantum leap would be to go down the route of super magnets/supe conductivity and the like, but that would not be cost effective. And unlike the electronics you talk about (valve to transistor to IC chip and miniturisation), with wind there is no economy of scale. Wind turbines cannot all be packed together in high density since the closer they are packed the less wind energy they can extract. They will always be one off individual units spaced far apart with their own individual foundations.
Electric cars are flogging a dead horse. They are not green and the inherent design problems are too deep seated to make them viable. Trams could be viable since they do not depend upon power storage.


My objection to renewable energy is due to its low energy density, and how the scale of the issue is neglected, especially in terms of its necessity for mitigating fossil fuel use.
To get some idea of the scale of power demand now and the capacity for renewables (specifically solar) to be able to meet it, I did some back of envelope calculations which I am sure could be improved on. It seems to me that the scale of future energy requirements require a solution orders of magnitude larger than anything that could be provided by low density so-called “renewable” energy. (Perhaps someone could improve on my figs…?)
– Currently, according to Hans Rosling, around 1/7th of the worlds population use half of the worlds energy.
– In 2008, world energy demand was about 149 Pwhs (according to wiki).
– If, based on 2008 numbers the top 1/7th energy users could improve efficiency of energy usage by 25% (optimistic I know), which becomes the model or upper limit for the rest of the worlds population, and we further say that we have to allow for every human being on the planet to have equal access to energy, then by the time the population tops out at around 11 billion, we will need to be able to produce and deliver 4 times more energy per year than we do now. This is a moral point rather than a practical point – I have no idea whether the poorest people will be able to make sufficient economic progress in 40-50 years from now, but it’s not unreasonable to suppose they might, and more to the point they should have the same right to energy that the developed world does.
– I used this website as a basis for making calculations and their numbers. Googling around it seems to be fairly well agreed:
– You can get very roughly 1 kwhs per day from 1 m^2 of PV. That’s assuming: 4-7 kwh/M^2 insolation and 20% efficiency. Obviously some days will be cloudy, and although PVs are about 6-20% efficient, lets assume they can become more efficient and you could get the average to that.
– So ~365 kwh/year/ m^2.
– So at 149,000 Twhs/year you would need (if my calcs are correct) 408,219 Km^2 of solar PV. That’s about twice the area of the UK.
– If half of 149,000 Twhs is for 1/7th of the population, and we want to spread energy usage evenly, AND we manage somehow to make 25% efficiency savings on how much energy we use, we would need, about 55,000 Twhs plus per billion, or 615,000 Twhs per year for a population of 11 billion.
– Just for fun, if this were all to be supplied by PV, at the levels calculated above you would need about 1,685,000 km^2. About 6 times the size of the UK or about 2/3 of Western Australia.
Not-with-standing the rather extreme nature of a venture of that size, and even allowing for the other renewable technologies such as geo-thermal and hydro which reduce the need for all of the energy to be supplied by PV, there is the problem of transmission. On a post recently at WUWT rgbatduke explained why you it is not efficient to transmit electricity more than 300 miles, however it was pointed out to me at Jo Nova’s that there is in fact HVDC which resolves the problem of transmission over large distances to a certain extent. I would love to have some comment on that from someone knowledgeable regarding pros and cons.
I am not in favour of any low-density solution. I’m not keen on fossil fuels for similar reasons: its energy density means you need to dig a lot of it up, transport it to be refined, refine it, then transport it to where it needs to go. But it is far superior to the alternatives proposed – save for nuclear and in particular modular nuclear and nuclear fusion. All of the renewable solutions require what I think to be an unacceptable degree of impact on the environment. I believe the only realistic solution is high density small scale modular nuclear energy that can be placed easily within the existing infrastructure and does not require large scale new infrastructure to be built.
It’s looking at the scale of the problem, the moral imperative to ensure all of the worlds population have an equal access to energy, that makes me think that the solution requires something of an order of magnitude that renders renewable solutions redundant.

Curious George

This article simply says that we don’t have yet a viable energy storage technology. So it can’t solve the problem of intermittent power sources – today. Big deal.
I don’t think we should invest astronomical sums of money into intermittent sources until an energy storage becomes viable. To imply that it will never become viable is disingenuous. But to build wind / solar capacities without an idea what a future energy storage technology might be is irresponsible. Criminally irresponsible.


Barry Brook at the University of Adelaide is a believer in problematic anthropogenic global warming as anyone would know who has attended one of his informative seminars. Having noted that I am sure Barry would view some of the shenanigans with tree rings and the thermometer record with some scientific concern. Nevertheless he has consistently argued that in response to his and others concern over anthropogenic warming, that the only solution (and here he would no doubt also include rational concern with peak oil, deforestation for LDC fuel use, etc) is to embrace nuclear power generation technology. That has made him somewhat of a heretic among the usual gaggle of Green catastrophists, but still a scientist of true integrity and insight into real solutions to a perceived problem. It’s there for all to see in his analysis.


At least for now one of the most cost effective large scale batteries is the EOS Aurora. They are supposed to be testing one in NYC right now. The trouble is this “cheap” battery is still $1M / MW (or $1B / GW). You can make traditional power plants for that type of money. The “savings” is that the battery has much lower operational costs so if NYC needs another GW of peak power on hot summer afternoons, then in theory 1,000 of the EOS Aurora batteries can be installed. Each one can provide power for 6 hours, so that is long enough to cover the afternoon peak. Thus you can in theory save some fuel. It seems to me they will have to burn extra fuel at night to charge the batteries so I’m not sure how well in works out in reality.
Does NYC have a spare GW of base load power on summer nights?
I forgot to talk about size. Each one MW battery is the size of a semi-truck, so if you want a GW worth you have 1,000 of them to put around. Not a trivial task and will likely drive that $1B price tag significantly higher.

David Larsen

Wait until we go into a cooling period similiar to the one a thousand years ago. Less wind and sunlight. Wonder what that will do to wind turbines and solar panels?

Svend Ferdinandsen

The problem besides the economy is that you have to build double the capacity of these intermittend sources and on top of that just as much storage capacity. I am not even sure the land will be enough.
Without storage you need the old powerstations anyway to supply when the wind and sun stops, so you only save a small amount of fuel, but need the old powerstation running idle from time to time.


I think that double source capacity is an low estimate. If the storage is not fully charged most of the time it can’t be relied on. On low generation days (cloudy, calm) triple or quadruple capacity might not be enough. If the system cannot supply very day of the year it is just an expensive toy. A grid crash is catastrophic.

Martin 457

They should use the power right away when they have it. Not try to save the power. Make a product that’s marketable and storable that would usually be made with power from the normal power grid and reduce the load that way. Then they wouldn’t need to tie them into the grid at all.
Just an idea. I wish them bird and bat choppers would dis-appear.


Anthony, Thank you for posting this. Its high time people begin to connect the “energy dots.” Its a shame more do not know the difference between energy, power and technology.


Joe Crawford wrote;
“However, I would have thought that this sort of analysis would have been common in the energy sector for a long time. But, as with most unique discoveries in engineering, once made everyone wonders why it wasn’t there all the time.”
This knowledge HAS been there all this time, but folks that really believe they can control the climate don’t want to hear it. A Mr. H. Ford hired a Mr. T. Edison back a hundred years ago (or so) to “make a better battery” for his electric car (Yup, Henry Ford, the man most responsible for inexpensive internal combustion powered automobiles also tried his hand at an all electric car). After half a year or so Mr. Ford inquired about the status of his “better battery”, Mr. Edison replied, “I have not found it yet” (paraphrased), Mr. Ford was disappointed, Mr. Edison replied; “But, I have found 50 approaches that do not work” (paraphrased).
During the last “energy crisis” (circa late 1970’s) many of the US National Labs were searching for the “perfect flywheel” to “efficiently store energy (cost, losses, safety, volume, etc.) “. Once they realized the problems with scaling up such technology (said problems still exist; cost, bearings, containment for safety, efficiency, etc.) they wisely gave up.
Effective storage of electricity on the scales needed for our modern needs is still a “pipe dream”. And the person who reduces it to reality will be richer that Gates, Buffet, Rockefeller and all those other “old dead (or eventually dead) guys” combined. Unfortunately governments will never accomplish that goal, the laws of physics WILL pick the winners and losers, the government cannot.
The only practical ways (currently) to store large amounts of electricity are; pumped hydro-power installations and piles of coal. All the “good” places for pumped hydro-power have already been spoken for, and nobody wants a pile of coal in their backyard.
The engineers version of the laws of thermodynamics; 1) the “best” you can ever do is to break even, 2) you can’t ever reach rule #1, 3) you can’t even quit the game, it goes on, no matter what you believe.
Cheers, Kevin.

Reblogged this on Centinel2012 and commented:
Its not hard to run the numbers and find that this is true — i spend the time and did this a number of years ago it wind and solar just do not work.

Mike McMillan

rgbatduke August 26, 2014 at 3:02 pm
Perhaps they cannot completely ameliorate the problem, but they can go a long, long way towards ameliorating the problem, …
Prof Brown has the right take here. Until we come up with his science fiction super battery, incremental storage improvements will help smooth out the on/off nature of wind and solar, which is what tears up the back up generators.
The Ivanpah solar bird scorcher stores its working fluid in huge insulated tanks, which lets its generators run into the night. There isn’t any conversion of the captured heat into something else for storage, so those losses are minimized.
Storage is the big bottleneck, so that’s where the bucks should be going.

A C Osborn

Yes really great, you are going to lose 30% of the Energy produced by the Wind or Solar, which already has efficiency problems.
Plus you still need backup.
Why bother when Fossil Fuels and Nuclear work so well?

Owen in GA

Isn’t there a materials science problem there that it is very difficult to contain the molten salt. It tends to eat the pipes that carry it. Metals fatigue quickly and most plastics won’t hold up to the temperature, ceramics tend to not be able to stand up to the pressures. I understand this is the long pole in the tent for pebble bed reactor technologies as well – how to contain the liquid salts that carry the heat. Doesn’t make much sense if you have to reconstruct the thing every couple of months to years.


***if only those pension funds would cough up the dough!
26 Aug: Reuters: Christoph Steitz: INTERVIEW-E.ON bets on investor help for wind power push
The group’s board member in charge of renewables told Reuters green energy was now growing as a source of profits for the utility, but that it needed help from investors for large wind power projects as its own investments were being cut to tackle its 29.7 billion euros ($39.2 billion) of debt.
“We have a big pipeline of developed onshore (wind) projects. But E.ON can no longer meet the capital needs for these projects on its own,” Mike Winkel said in an interview.
“Therefore, financial investors are very welcome to join and it turns out they see this market as being quite attractive.”…
***Last month, Denmark’s DONG Energy A/S agreed to divest 50 percent of a German offshore wind farm project to a group of Danish pension funds, freeing up capital to expand its offshore wind business…
E.ON’s smaller German peer RWE has also said it needs the help of external investors for big wind power projects, which swallow investments of at least 1 billion euros and carry greater risks when erected offshore…


CRS wrote…
From the link;
“A small startup based in Emeryville, California, will build a pilot-scale energy storage system that COULD provide a cheaper, more practical way of storing large amounts of electricity”.
Not sure I agree that a “small startup” building a “pilot-scale” energy storage system that “could” (from the link) really counts as “simple” and “proven”. Sure a technology has been identified, but there are lots of steps between that and practical electricity storage. And the molten salt energy storage idea has been around for a long time, nothing new here. Ever try to fix a leak in piping that contains molten salt ? Better get some really good gloves and glue (maybe some super-duper-extra-strong-very-high-temperature glue)…..
Cheers, Kevin.


the reality McKibben & Co can’t accept:
26 Aug: Bloomberg: Zain Shauk: Investors May Find It Hard to Break Up With Oil and Gas
Investors seeking greener energy stocks will find it difficult to reproduce the returns offered by oil and natural gas producers, according to a report from Bloomberg New Energy Finance.
With a market value of $4.9 trillion, oil and gas investments offers a combination of scale, growth and dividends that can’t be readily found in other industries, the London-based research company said today…
Environmentalists have proposed fossil-fuels divestment…
The divestiture movement is backed by Bill McKibben, an environmental writer and co-founder of, a group that has identified 200 companies with the largest reserves of coal, oil and gas. McKibben warns that fossil fuel companies hold undisclosed financial risks as governments move to limit emissions blamed for global warming.
“If you are investing in fossil fuels, you are essentially betting that we won’t ever take climate change seriously,” Jason Kowalski, U.S. policy director for, said in an e-mail. Smart investors are moving “their money sooner rather than later.” …

Grey Lensman

I think that the Germans have solved it. Run lignite at 100% but control output. Only supply on peak demand and make huge profit. Burns a lot of fuel but hey makes a profit and no blackouts.


Can anyone answer this for me please. From what I have read the salt generally used for molten salt storage in solar thermal power generation is Sodium Nitrate (an oxidizing agent) and the heat transfer fluid is high temp oil (hydrocarbon). If a heat exchanger ruptured what would prevent the following?
Oxidizing Agent + Carbon (or hydrocarbon) + Heat = EXPLOSION


Agnostic says; On a post recently at WUWT rgbatduke explained why you it is not efficient to transmit electricity more than 300 miles,
BC hydro has a 500 kv transmission system that has been in operation for almost 50 years now.


Oops cut my post, the 500 KV transmission system is over 500 miles long.

A C Osborn

And how much energy is lost in transmission?


The existing nets usually locate plants within the 300 mile radius, although there are exceptions and the delivery networks are interconnected so that they can keep whole regions “up” even if there is a local disaster, at substantial cost. One “can” transmit energy any distance you like — it just gets more and more expensive to do so. And I don’t think anybody thinks that we can transmit it (say) 10,000 miles without completely re-engineering Tesla’s delivery system. In the meantime, there are scaling laws that suggest that one would have to go to much higher voltage and much larger transmission towers to accomplish it (or else build a lot more lines to run at the lower voltages and pay the cost of lower efficiency).
Which could happen — people are hard at work on suitable high-ish temperature superconductors that might enable low-voltage transmission, DC high voltage transmission (which can use the entire cross-section of a power line instead of the outer cm or so), and other stuff, maybe transmission in high-efficiency waveguides. The point is that our existing grid cannot transmit energy from Mexico or South Texas desert where it is easy to make solar energy most of the time on otherwise worthless land to Maine or Alaska, where they need energy in the long dark winter.

Pumped storage. Equivalent to one large nuclear power plant: of say 2 units each of 1,000 Megawatts capcity. Each capable of running 24 hours per day, 365 days per year at a 90 – 92% on-line service every year. Cost too much? Take too long to build?
Or 3 combined cycle power plants at 63% thermal efficiency, each combined cycle rated at 670 MegaWatts. Similar CT’s are built in two years, cost right at 250 million each, and would require about 50 acres of unimproved dirt.
But you want pumped storage.
OK. Build another Hoover dam on some convenient river, complete with 17 unit water turbines and electric grid transformers. Add a 50 mile lake upstream in come convenient place that won’t get in anybody’s way. And won’t disturb wetlands, fish, ecologies or ducks or beavers or moose or deer or butterflies. Now build a SECOND Hoover Dam nearby, AND a second lake, AND a second power plant and pumping station. Each night, pump the lower lake into the upper lake – Kind of like pumping a full day’s release of water from Lake Meade (behind the Hoover Dam) back upstream to refill the Lake behind the Glenn Canyon Dam by using the power from the lower dam’s turbines…
The next morning, drain the upper lake into the lower lake running its water through the pump-turbines.
Simple, right? Remeber, Niagara’s pumped storage units ONLY WORK because of the natural drop from Lake Erie through the tunnels that bypass Niagara Falls themselves. No Lake Erie, no Niagara Falls in your backyard = no pumped storage economies.
All of this – and ten years of construction to replace a simple CT power …
Oh, by the way…. Lake Meade is running out of water right now. So is Glenn Canyon. The power output has already been de-rated from 2074 MegaWatts down to 1592 MegaWatts, and may need to go down again to only 1050 MegaWatts if the drought continues.

pat August 26, 2014 at 7:27 pm
the reality McKibben & Co can’t accept:

The divestiture movement is backed by Bill McKibben, an environmental writer and co-founder of, a group that has identified 200 companies
Is that a public list? Just reviewing my portfolio so a list of these “evil doers” and the dividends they pay would be quite useful. (Although I suspect I already own a number of them) I see we have another Hollywood Actor (DeCraprio?) up visiting Fort MacMurray so he can slag the Canadian oil sands in an upcoming movie. Wonder if he walked up there? Oh silly me. Took a helicopter powered by magical beans I reckon. The methane producing kind, funnelled from the occupants with tubes up there butts to the highly efficient engines. Now there is a story line for you Leonardo. Naaaahhhh, probably too believable.

Rud Istvan

Anthon y, I will separately provide you a comprehensive essay on this from my forthcoming book. Focused only on California. Should hit home. Facts are worse than anything yet posted here.

Claude Harvey

I don’t think some readers are getting the point here. According to the European experience, photovoltaic solar costs 8 to 10 times the current U.S. average price of wholesale electric power, at the fence, without taking into account the conventional power sources required to cover the “intermittent” problem. If you fold in the actual cost of either energy storage or backup power sources necessary to make solar work as a practical matter, the cost is simply ruinous.


And you need MORE of the expensive PV solar to charge the batteries.

Non Nomen

August 26, 2014 at 2:29 pm
A pumped storage system may work where there is a large elevation differential…Dig 20 small (?) reservoirs cascading one into another, with 20 motor-generator set-ups ….
A pilot set up could be done on Maui as there is a 10,000 foot elevation gain over a few miles…Getting permits to dig mother Maui is another matter…
Why don’t they go underground completely? Caverns that formerly held potash are the downend of the pipe and a nice litte lake on the surface(or even another cavern) is the other. It should work as long as the downward slope is ok and gravity doesn’t cease.

Mericans are lucky since you have not yet travelled far along the road to renewables utopia. In Scotland we are planning to have 100% equivalent renewables by 2020. In Scotch on The ROCs I analysed the consequences of a full year generation at 5 minute resolution. We generate a massive and expensive surplus that has nowhere to go:
Anthony, you are welcome to re-blog this if you like.


And then put a 24 hour low pass filter on that wind ‘signal’

Stephen Richards

However, hydroelectric capacity is not readily scaled up as it is restricted by suitable geography
and climate change !!


I know I should not encourage the windy/solar lot but vanadium batteries look pretty good…


Grey Lensman
August 26, 2014 at 8:11 pm
“I think that the Germans have solved it. Run lignite at 100% but control output. Only supply on peak demand and make huge profit. Burns a lot of fuel but hey makes a profit and no blackouts.”
We do have a lot of small 300 MW class gas power plants here in Germany which should be very good in compensating for wind power fluctuations. Often they sit right in the center of a wind turbine “park” – which has grown around them to exploit the feed in structure of the existing grid.
Also, many municipalities have combined cycle plants, mixed operation gas and coal, for district heating and municipal power generation. These are also small plants that should be able to ramp quickly.
It would be extremely un-German to burn fuel and discard part of the power. If you have links that show that this is actually happening to any significant degree, show them please.
There were some explicit gas peaker plants that EON threatened to mothball because they only could operate profitably an ever decreasing number of hours per year – most of the time solar+wind swamps the grid. So there are talks underway to compensate owners of these plants for keeping them as reserve. Doubtlessly an expensive market distortion, but all of this has nothing to do with burning lignite and discarding the output.

Did they look at hydrogen?


I looked at the site. The guy claims he wants to educate the public about hydrogen. So I looked for the education about Hydrogen seeping through metal and making steel brittle. It’s funny, but on his entire website he doesn’t mention any problems. If I were educating the public about Hydrogen, I would be less irresponsible. Or in other words: that’s a hype page with as much substance as an issue of “Wired”.


So frustrating. You are assuming a 100% solar and wind grid backed by batteries – yes that is a stupid solution. However, there are nuclear plant upgrades whereby Nat Gas is injected into the hot air stream and burned at (I believe) 63% efficiency and can boost output by 300MW (I need to find the link). There is no spinning reserve, just a quick on/off on a plant that is already contributing to baseload. If we instead of assuming 100% wind and solar we ask “what is the best use of resources for the next 50 years” we might want to look at a way to drop combustion from 80% to 40% of our grid and we might ask is that a possibility? Perhaps we would be better off if we switched electricity (as much as possible) away from Nat Gas (ramping up coal and renewables) and used $1.50/gal equivalent Gas to replace gasoline at $4/gallon. The question then becomes not whether it is cheaper to make electricity from Nat Gas or solar, but whether it is better overall to use Nat Gas for transportation.
We would need a ~5 minute battery to level out wind turbines starting/stopping and compensating for cloud cover. We would need a ~20 minute energy storage system like compressed air/liquefied air/thermal storage/pumped hydro, 3 hour solutions like peaking plants, then reserve units that can fire up when there are several days in a row when it is hot, cloudy, and windless (odd combination). All of these are existing technologies. What we should be doing is not to use pumped hydro to store 2 days of electricity demand, but to give peaking plants (which already exist) time to ramp up/down.


Or you could just decomission the wind and solar and eliminate the complicated, unreliable and expensive buffering measures.


First – those buffers are already on the grid, it is merely a discussion of scale. Second, you missed the point entirely. Let’s say you have the option of $0.10/kWh electricity and $4/gal gasoline. An alternative is $0.15/kWh electricity and $1.50/gal gasoline. Has the price of electricity gone up? Absolutely. However, your total energy bill very well might go down since you are effectively replacing diesel with solar/wind by moving Nat Gas up the value chain. The cost of Nat. Gas. is much higher than it would be if everyone in the NE were still using heating fuel instead of Gas for home heating. However, the total heating bill has gone down by replacing an expensive fuel (petroleum) with a much cheaper one.


A pumped storage station was built in the Virginia mountains in the 1980’s that is now capable of 3000 MW of generation, storing over 20,000 MW hours of energy. Its full storage/generation capacity is used every day, largely fueled from coal and nuclear sources, the input from renewables is almost negligible.
I doubt it could get built today due to permitting restrictions.


Wind/Solar should be reserved only for the situations where it really makes sense, just like hydro. It will never supply 100% of energy needs, but if we could get it to 25% that would be massive. We still need common sense energy solutions that don’t pollute. Thorium fission or small-scale magnetized target fusion come to mind.


“Thorium fission” . . . you really said that.

Jake J

The key is this:
Weißbach et al. calculated the EROEIs assuming pumped hydroelectric energy storage. This is the least energy intensive storage technology. The energy input is mostly earthmoving and construction. It’s a conservative basis for the calculation; chemical storage systems requiring large quantities of refined specialty materials would be much more energy intensive. Carbajales-Dale et al.2 cite data asserting batteries are about ten times more energy intensive than pumped hydro storage.
I chased down the citation, and it did not appear to support the claim that battery materials and manufacturing are too energy intensive for use as grid-scale storage.

Grey Lensman

Dirk, it is in one of the earlier posts. Seems they run at 100% but vent the heat rather than spin to generating power. Then when the demand comes, at very high prices, they just close the bypass. No more blacks outs but no reduction in fuel use

Grey Lensman

[Full reply prompted by one of RGB’s posts]
Unfortunately, we’ve been using and trying to develop new batteries for decades. While technology has evolved somewhat, I’m not convinced we’ve come anywhere near the breakthroughs we need to truly make solar and wind both cost-effective and realistic. Others also make this point.
The telecommunications industry — among others — still uses vast amounts of batteries to power and provide back-up electrical capacity for “switching stations” or “central offices”, including the electricity pushed out through traditional twisted pair copper lines to ring the wall phone and power the basic capabilities of the traditional phone. Yes, even in this day of fiber optics it is so…
The best batteries on the market — economically — are what they were 20+ years ago: wet cells (sulfuric acid and lead plate, or similar). Same holds true for data centers. If you have never been in a significantly sized datacenter battery room, you should try to find a way to get there (legally). Huge room with ginormous battery racks, holding hundreds of 1,000-pound or larger batteries containing literally tons of battery acid (even if calculated to a “pure acid” equivalent).
Smaller switching stations often have smaller batteries, which may only last for 5-7 years, while the big sites may have big, boxy batteries that may have a service life of 20 years.
If new tech is not showing up in the telecoms and datacenter industries, some of the most “large scale” applications for bulk electrical storage that face real competitive pressures, it’s clearly not ready for prime time, much like solar and wind were pronounced during the Carter Administration.
I’m simply not convinced about the overall viability of storage systems, other than pumped storage, which I dare say will not expand under current and future environmental laws and regulations. While RGB raises some good points, his discussions are heavily sprinkled and sometimes loaded with “IFF” statements
(IFF = if and only if). Read them again to see how we need large enough batteries, and cheap enough solar cells, if anyone ever figures out how to resolve the deal-killers in the engineering, etc.
Ripshin also hits the nail on the head with his comment that while solar energy is free, collection is not. (Ditto for wind.) Along with collection comes a need to transport, which is also not free, and none of these systems are maintenance free, or indestructible (think fire, wind storms, hail, etc.). Nor are they continuous.
I’m an engineer by training, working in risk management. Personally I hope these breakthroughs happen and happen SOON. But, show me facts, show me definitive progress with demonstrable cost-competitiveness without subsidy (FWIW, I believe everything should be compared without subsidy, BTW).
Keep in mind that in my experience, in the U.S. especially, we tend to latch onto the promise of technology and technological advancement early, often before the technology has been adequately tested and proven. Look, for example, at “weathering steel” more commonly referenced in structural engineering and architectural circles as COR-TEN (a U.S. Steel Corp trademark term): There are serious downsides, but it was tried in many situations (not documented by wikipedia, naturally) where it fared quite poorly. Wikipedia does note a few important installations that failed miserably, however.
There have also been environmental (sewage treatment) technologies that were rushed into service with great promise, but that turned out to be spectacular duds. For example, EPA’s push for something called “Breakpoint Chlorination” back in the early 1970’s was a failed though heroic attempt to have it applied nearly everywhere for nitrogen removal based on pilot plant testing at but one or two locations. I know of one site at which is was installed to treat about 36 million gallons of sewage per day — many orders of magnitude larger than for which it had been demonstrated — only to have the state declare it a “brute force approach” that was approved for temporary use only. EPA’s guidance evolved thereafter to [eventually] drop the idea completely (in the never-published 4th edition draft document, naturally). There are other examples.
Most of the above discussion in this thread did not address the need for “spinning reserve” to back up solar and wind if the batteries don’t exist. Likewise such sources will probably also need to spin if the batteries/storage systems do exist, though perhaps they can be powered down somewhat further: if drain/demand on the batteries/storage becomes excessive or prolonged, we otherwise should expect to have one of them thar things called a brownout — or a blackout.
There is an argument that we should not be looking to store “excess power” but to use it instead. If you use it, it’ll be hard to heat the water for your morning bath/shower overnight, or to energize your ultra-efficient CFL and LED light bulbs at night. In my home, I believe we use far more electricity for activities that begin as the sun’s greatest intensity is past, and before it begins anew the next day, than we do during the day. One minor issue with “making something” with excess power is that in the U.S. we have these pesky things called air emissions permits (water, too) that limit manufacturing emissions in various ways, sometimes by shift, hour of day, and so on, with totals that may not be exceeded without financial penalty. Another pesky problem is how you adjust the labor force for such activities on a day-by-day basis; we know the meteorologists — good though some of them are — are not perfect, so what do we do when storms that were not in the GFS, Canadian or European met models actually show up and screw the solar intensity so that there is no “excess”, or conversely when the storms that were forecast DON’T materialize and there is “excess”?

The main issue is that wind energy will never contribute to the overall energy mix in any reliable manner that’s even worth storing, while solar energy CAN be easily (!) stored – as warmth/heat. The nonsense starts, when you use photoelectric effects with a third of the efficiency direct heat capture has. And then in the next step ask for batteries. This is like Groucho Marx planning the energy landscape.