The Energy Storage Problem

Prakash-and-reactor2GreenEnergy megasupporter Cameron Atwood just sent me this from G.K. Surya Prakash (pictured), a chemistry professor at the University of Southern California: “Earth doesn’t have an energy problem. We have an energy storage problem.”

There is no doubt that the advent of cheap energy storage will go a long way to enable the migration from fossil fuels, both by a) facilitating the integration of variable resources, i.e., solar and wind, and b) by eliminating the need for liquid transportation fuels.  The first of these, however, can also be achieved by overbuilding the solar and wind infrastructure, and by enabling high-voltage transmission over vast distances.

I believe that there are no absolutes and no silver bullets, and that a great number of different ever-improving technologies are all working together in an endless path of improved cost-effectiveness to eventually win the day.

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17 comments on “The Energy Storage Problem
  1. Cameron Atwood says:

    I’m encouraged that there has recently been increased discussion in high political circles about updating our national power grid to facilitate wider renewables participation. I hope it turns into more than talk, as the need and availability of solutions are both rising daily. The only barrier to progress in this arena is politics.

  2. Breath on the Wind says:

    The contrary perspective is one that I appreciate. It is sometimes a good rhetorical device to offer the surprising statement that runs contrary to common conceptions.

    And it does serve as a way of asking us to examine the issue a bit more closely. I actually thought he might go off into an explanation of climate change as one of storing too much energy on the Earth. The problem with statements like this is while true they may not be helpful.

    We are exploring alternative energy sources not because we need more energy, but because we need a different source of energy than fossil fuels. Not all energy is created equally.

    The statement is true because there are enough sources of alternative and renewable energy to many times over satisfy the world’s energy needs without fossil fuels.

    The statement is true because fossil fuels have a (concentrated) energy component combined with a storage component, (plus a chemical component.) On the contrary, many sources of alternative energy only give a diffuse energy component and lack concentration and storage. Concentration has proven to be relatively easy for both heat and electrical sources. Storage is more challenging.

    But the statement is not helpful by pushing to the side issues associated with expanding alternative energy sources. They are not technical problems. We know how to acquire the energy, but political problems associated with alternative energy development continue to plague us. To the chemistry professor political problems do not exist and storage problems are the only reality.

  3. Frank R. Eggers says:

    Here is an article in the Sydney Morning Herald that covers some of the challenges experienced when renewable energy systems achieve a high market penetration:

    http://www.smh.com.au/business/renewables-shift-brings-threat-to-power-supply-20160921-grl0bs.html

    The article also covers, to a limited extent, the use of batteries for storage. Note also the link to an article about experience in SA.

    Here are quotations from the article (note especially the statements about battery storage):

    That raised the question of whether the existing system can cope with a renewable energy supply above 35-45 per cent of the total.

    ‘Can’t get much higher’

    “No one knows, but it can’t get much higher,” says the Grattan Institute’s energy program director Tony Wood. “You can have more, but you need flexible generating capacity such as gas or hydro.

    “Even demand-response [where large users have financial incentives to turn off], there is a fine line between demand-response and load-shedding [forced power cuts].

    “Too much or too little? Too much, dump it or store it, or too little and being out of storage.”

    Battery storage can be handy at the small-scale level, he said, although there are doubts about large scale battery storage.

    “The alternative is for those exposed to outages … being forced to invest in batteries for example.”

  4. Breath on the Wind says:

    Frank, prompted by Craigs recent posting about Joe Romm ( http://www.2greenenergy.com/2016/09/25/energy-environment-2/ I found this talk in which he addresses many of your points in a talk entitled, “What you thought you knew is obsolete.”

    You may find it a valuable update on the state of climate and energy issues: https://www.youtube.com/watch?v=P6ag3b1WCYc

    I am not sure if this is the talk Craig wished to reference in his posting.

    • Frank R. Eggers says:

      It might be the one. However, I’m not really inclined to watch videos, especially long ones. I much prefer to read the material since doing so is much faster. Also, if necessary for a thorough understanding, I can quickly and easily re-read portions.

  5. Breath on the Wind says:

    Regarding large scale battery storage this is just in regarding a battery storage solution for Los Angles: http://inhabitat.com/tesla-to-install-worlds-largest-backup-battery-for-the-city-of-los-angeles/

  6. Frank R. Eggers says:

    Breath,

    Tesla’s experience is with lithium ion batteries. Currently they seem to be the best choice for EVs and hybrid vehicles. However, that doesn’t necessarily mean that they are the best choice for utility scale storage.

    For EVs, batteries have to have a very high energy to weight density. For some hybrid cars, they also have to have a very high power to weight density. For utility scale storage, that is not necessarily the case because weight really doesn’t matter and size is also less important.

    It will be interesting to see how this works out and what the costs are. If the costs are within reason, it could greatly reduce the need for spinning reserve.

    To make intermittent sources of power practical, considerably more storage would be required than to level peaks.

  7. Breath on the Wind says:

    Frank, everything you say is true, yet there it is in the face of all reasoning and possibly even economics. If you read the article it says that Tesla was the only bidder and they expect to have the contract completed from their yet incomplete factory in about 3 months.

    It does make me wonder if this was a bit of political manuvering to make an opening for Tesla. For Tesla the incentive would be to make an early profit, put their name in lights and not worry too much about the efficiency.

    Economics of scale may trump technological efficiency in this case and “seeing if it works” along with all the pundits rhetoric may be outdone by a completed installation.

    The petrol car was never a perfect vehicle but it was in the end the one that was mass produced.

    • Frank R. Eggers says:

      Breath,

      I hope that it does work. However, even if it is found to be economically justifiable for peak leveling, or at least reduces fossil fuel usage for peak leveling, that does not necessarily mean that it would work to make renewables practical. For renewables to be practical and not depend on fossil fuels for backup, enough storage for a few weeks might be necessary. If considerable wind power is used, a few months of storage would probably be necessary.

      It will be interesting to see how this works out.

      You may find this web site interesting:

      http://www.CleanEnergyNM.org.

      Among other things, it discusses different battery technologies, although with inadequate thoroughness and no cost information. I had an interesting person to person conversation with their bureau chief whom I met at a Power New Mexico meeting. Quite honestly, I was appalled. He knew almost nothing about nuclear power, new nothing about enriching uranium, etc. etc. Later I sent him an email pointing out the need to be familiar with ALL energy technologies and viewpoints. That is something that entirely too many people do not understand.

      When I was a member of Toastmasters International, we had a debate. My assigned partner and I were assigned a position with which I disagreed and we won the debate. As I see it, a well-informed person could, as an academic exercise, do a good job of supporting a position with which he disagrees. And, unless one thoroughly understands opposing viewpoints, one cannot effectively support one’s own viewpoint. Unfortunately, that is not widely understood.

      In discussing a viewpoint, I find it helpful to make it clear that I thoroughly understand opposing viewpoints. That keeps the other person from constantly repeating his viewpoint when I already understand it even though I disagree with it. The concept of understanding something with which one disagrees seems very difficult for some people.

      I also find reflective liststening very helpful.

  8. Breath on the Wind says:

    Frank, thank you for a reference to the NM site, although I find sites that attempt to give a general knowledge lack and interesting depth. I tend to prefer reading more focused items like ” a chart of common phase change materials and calculations for specific and latent heat.” (for a current project) Perhaps this is one reason I don’t have a lot of patience for articles that promise “6 green cleaning tools for the home…” Although there does seem to be a big market for this type of writing/reading.

    I have studied and written about various battery technologies. Of those I find the nickl-iron battery most interesting for its durability, the lithium-air battery interesting for its potential energy density by weight. I generally find substitutes for lithium interesting. The NMHi has an interesting political history. You will note that these are all transportation batteries. And they reflect a large portion of reading in electric transportation.

    Flow batteries and sodium batteries as well as atomic batteries I have also found interesting. But if the EV market produces second hand batteries at a substantially reduced cost and in volume then more appropriate alternatives for stationary batteries may be priced out of competition.

    When it comes to a review of batteries, more important than the technology or chemistries are the desirable qualities: life cycle, power rating, cost for power density, overall energy density, cost per watt, the ability to deep cycle, operating temperature (and its effect on efficiency.) Part of the difficulty with batteries has been that improvement in one area often implies a compromise in another.

    But I also think that a stable, probably chemical, thermal battery could possibly be even more game changing than an electrical storage battery.

    Congratulations on your debating skills. No doubt you were a formidable and knowledgeable opponent. My own efforts in that are were often met with a little shock as I had a penchant for defending what was expected to be an indefensible position (why an apple with a worm in it is better than one without…)

    I don’t understand your suggestion that wind generation is going to require months of energy storage particularly when compared to the energy storage that is deemed practical for solar thermal power plants… about 4-6 hours, not 12 or 24 hours as one might think. Every source I have encountered suggests a relatively small amount of energy storage. Usually it is based upon the size of the grid ie 5% of daily usage… I am not sure what “months” of energy storage actually means? It doesn’t seem to contain a quantitative reference. Could you be considering some research?

    Grid level energy storage devices I have researched and come to appreciate include flywheel energy storage (mostly for frequency regulation https://cleantechnica.com/2011/08/11/pennsylvania-beacon-power-flywheel-energy-storage/ ) and heat storage using heat pumps: https://www.greentechmedia.com/articles/read/Isentropics-Pumped-Heat-System-Stores-Energy-at-Grid-Scale The article also says about 3 hours of storage is most practical (presently?)

  9. Frank R. Eggers says:

    Breath,

    I share you attitude towards web sites similar to the one for which I provided the link.

    It is very difficult to get quantitive information, including cost, energy density, power density, degradation from repeated cycling, etc. etc. When people inquire about the economic benefits of installing roof-top PV systems, they are given pay back estimates but not internal rate of return which is a very important to know.

    As for storage, it must be adequate to provide adequate power when no energy is being received. For wind that can be weeks at a time. Because wind is so irregular and varies greatly by location, an average figure for necessary storage would be of limited value. Coming up with reliable figures would require installing wind sensors at numerous locations and evaluating the results for years.

    PV solar requires clear sunlight and is therefore more affected by cloudy weather than PV, but there are times when both could be shut down for days at a time.

    I simply do not believe sources that minimize the need for storage. The second article for which you provided the link seems more concerned with the dollar value of storage than with whether it is sufficient to provide reliable power. It did not actually state that three hours of storage would provide reliable power.

  10. Breath on the Wind says:

    Frank you said “I simply do not believe sources that minimize the need for storage.” Then can I take it that you only “believe” sources that agree with your position and that “maximize the need for storage?” Would you at least agree that the amount of storage is not a matter of “belief” but a calculation.

    First you need to start with a level of reliability. Some 3ed world countries have very unreliable systems. They might be OK with minimal storage. In the US we come to expect a lot from the grid but it is not 100%. Hospitals, data centers and other places that require a higher standard have back up power supplies. Our standard might be: between 98% and 99% of the time reliable.

    Then we would need to consider a particular energy mix and not only the diversification of sources but the diversification of area. A wind turbine in one place could be failing but a solar or geothermal resource or a wind resource in another location might be available, obviating the need for storage.

    Reliability does not always demand storage. This article suggests that the cost of storage can be higher than the cost of overbuilding capacity: https://thinkprogress.org/falling-renewable-energy-prices-threaten-energy-storage-heres-what-we-need-to-do-b058349ccf5e#.iic6bkkn2 If this were not historically the case we would likely have far more storage today. A few years ago the Feds came out with a new pricing structure for energy storage and this should help to encourage cost effective energy storage implementations.

    Finally if indeterminacy is not a problem of belief perhaps it is a worry. But it seems to be a worry that is being resolved with experience. Here is one of the better articles I have found on the issue. The author seems knowledgeable and credible perhaps you will suspend disbelief long enough to see what he has to say: http://cleantechnica.com/2013/08/12/intermittency-of-wind-and-solar-is-it-only-intermittently-a-problem/

    • Frank R. Eggers says:

      I would have to see exactly how they arrived at the amount of storage required and see whether their method and assumptions seemed reasonable.

      Unfortunately, it looks as though there currently is no country which has achieved reliable power using only wind and solar. It is true that interconnecting wind and solar systems over a large area could, at least in theory, result in reliable power, but that would not necessarily be practical. For example, I seriously question the economics of moving solar-generated power from the Sahara Desert to New York City. Moving power such large distances might well be necessary to achieve reliability without storage.

      There are too many “mights”. At one time, it was widely assumed that simply interconnecting systems over a large area would result in reliable power, but those were only assumptions. I was never able to find even one evaluation based on installing wind and insolation sensors over a wide area, collecting data from them over a period of a few years, and analyzing the data to ascertain whether reliable power would be achieved via interconnections. That is what would be required, and as near as I can tell, it has never been done. Considering that it is such an obvious step, it seems strange that it has never been undertaken.

      Quite honestly, I do not see the linked-to article as very convincing. We are being urged to spend billions and billions of dollars on a power system without proof that it will work or is practical. Proof does not consist of showing that country has got 100% of its power from wind and solar for a very limited period.

      Many people who previously assumed that interconnection could make wind and solar reliable now acknowledge that it cannot without huge amounts of storage. But even with storage, the capacity factor has to be considered. Nuclear power plants have a capacity factor of slightly greater than 90%. It has increased from a bit over 50% in earlier times as better management techniques have been developed. Because of the low capacity factor of wind and solar, even with infinite storage the total rated power would have to be several times greater than if it had a capacity factor of perhaps 90%. That, of course, would greatly increase costs.

      We know for certain that nuclear power is capable of doing the job. Considering the urgency of the need to eliminate CO2 emissions, it would make more sense to expand as rapidly as possible a technology that we know is capable of doing the job. While doing that, we should be doing R & D to develop better nuclear power technologies. We should also be doing R & D to determine whether renewables can also be made to do the job. Then, if EXPERIENCE indicates that renewables can do the job, we could halt expanding nuclear power and depend on renewables.

      In general, we don’t expect millions of people to take a medication until it has first been tested on animals and small groups of people. Yet, we are supposed to assume without proof that wind and solar power are able to provide reliable power.

  11. Breath on the Wind says:

    Frank, thank you for sharing so much of your perspective in your last reply.

    – If there is no country that has yet decided to pursue only solar and wind it is likely due to existing infrastructure and available options. This is not evidence that it can’t be done. Because I haven’t driven from East to West Coast without sleeping doesn’t mean it can’t be done.

    – You do your positions no benefit by suggesting the absurd. No one is suggesting electricity should flow from Africa to NYC. It is practical to move energy long distances using HVDC but we don’t have to go 1/3 of the way around the world to find a breeze.

    Renewable power for the US East Coast will likely come from the massive wind resource available offshore from the same area that most demands the power. There is more than sufficient wind resources to fill existing and future demand. The anticipated explosion of offshore wind farms will likely be joined by the planned “Atlantic backbone” an offshore HVDC grid extension in the Atlantic. As I am sure you are aware offshore wind is generally both more reliable and stronger than onshore resources.

    – “There are too many “mights”. …it was assumed … interconnecting systems over a large area…” In the first instance. You seem troubled by uncertainty… Understand that “too many” is a subjective assessment. What you feel is “risky” someone else may pursue with absolute confidence. You seem to demand some kind of wind assessment study. I was reading about those 10 years ago. Now we have evidence from the European grid that demonstrates the viability of intermittent sources. You will find a reference to those in the article you dismissed as “unbelievable.”

    – You have given the CF of Nuclear the most optimistic spin. I have seen ranges from about 83% to about 91%. There is also a concern that in a warming world Nuclear will not be able to find adequate cooling resources. Current regulations require plants to cut back when temperatures move past 95 deg F. This is likely to have an increasing impact on the CF of nuclear.

    – As previously mentioned elsewhere, geothermal has a CF similar to nuclear. Solar Thermal with energy storage reaches the range of nuclear CF. Solar PV is handicaped by not producing at night but it is a very cheap way to produce power when it is needed. CF is likely to be less significant than the LCOE A similar cost argument could be made for wind. And we are completely leaving out hydro, a major renewable source in some locations.

    – The European experience is convincing us that renewables can “do the job.”

    … Can Nuclear “do the job?” Or are we beginning to see nuclear as an energy experiment that has failed. Regardless of other concerns cost of new nuclear is keeping such plants from being built. The French can’t even build a plant in their own back yard. Nobody wants the cost overruns. Nobody wants the operating cost … when there are cheaper alternatives.

    – I am not familiar with the “many people” you say have changed their minds about indeterminacy. It is a kind of throw away somewhat fallacious appeal to the masses or “experts” who remain unnamed.

  12. Frank R. Eggers says:

    Breath,

    You wrote, “There is also a concern that in a warming world Nuclear will not be able to find adequate cooling resources. Current regulations require plants to cut back when temperatures move past 95 deg F.”.

    I have never heard of such a thing. Exactly where are there regulations which require plants to cut back when temperatures move past 95 deg F.”?

    Some plants which use once-through water cooling have to cut back at times because of concern that the body of water they use will become too warm. However, that applies only to plants which discharge water back to the same body of water from which they withdrew it. With cooling towers that should not be a problem.

    Also, it is possible to design nuclear plants to use air cooling. To avoid losing efficiency, doing so requires reactors which can be operated at a higher temperature, such as metallic salt reactors, including the Lithium Fluoride Thermal Reactor. Unfortunately, they are not yet ready for deployment because government funding for R & D for new reactor types was cut off more than 30 years ago; it was said to be unnecessary. We are now paying a price for that bad decision.

    It should be noted that concentrated solar thermal plants are more efficient when they have water for cooling.

    Again, so far as I have been able to determine, there have been no actual studies to determine whether wind farms scattered over a wide area would result in reliable power. Doing such a study would require having wind sensors in many of the places where it would be reasonable to build wind farms then analyze the data over a long period of time.

    France went from zero nuclear power to 80% nuclear power for electricity in only about 17 years, although it has since dropped to 75% nuclear. France has demonstrated that it would be possible to go up to 100% nuclear power. There has been no such demonstration for intermittent sources of power. And, unlike solar power, sometimes the wind is not adequate for weeks at a time thereby making storage even more important for wind power.

    Yes, I want practically absolute proof that something will work before spending many billions of dollars on it; I see that as only reasonable. For something less important and less costly, a lower standard of proof would be acceptable. I will not accept faith as sufficient proof.

    • Breath on the Wind says:

      Frank, I can’t completely comment on your demanding “absolute proof.” Perhaps your standard is so high that not even Nuclear energy is viable and you would be left advocating nothing. The reason we do make decision is because there is a feeling that something must be done, that decisions must be made even with uncertainty.

      Here is a report from 2001 that seems to discuss France over dependence upon Nuclear energy. I haven’t had a chance to review it and unfortunately have to go about my day before I can comment on it. But I would invite you to take a look and share a review of it. http://www.ecn.nl/docs/library/report/2002/c02043.pdf

      I will get back with more comments when I have a bit more time. Have a good day.

  13. Frank R. Eggers says:

    Breath,

    I have bookmarked the article for later reading. Meanwhile, I have a suggestion. I did it some years ago but did not save the sources.

    Compare the material inputs for different power technologies, i.e., the material inputs of concrete and steel for wind, solar (multiple types), coal, and nuclear power for the same nameplate rating, perhaps one megawatt. I think you will find it very lopsided, especially for wind power which requires shockingly high amounts of concrete and steel. Solar requires considerably less concrete than wind. After compiling the results, then adjust for capacity factor by dividing the material inputs by the capacity factor which, of course, is less than unity.

    I think that if you put the results into chart form, it will indicate that nuclear power can be expanded far faster than wind and solar power.

    Regarding France, per the article France now gets 77% of its electricity from nuclear sources. France is now at a point where it could quickly expand its nuclear power if it chose to do so. So, if France’s choice to expand renewables doesn’t work out well, it can quickly back track and expand nuclear. If countries which now have a small percentage of nuclear power tried drastically expanding renewable power and it failed to work out, it would be much more difficult and take far more time to correct the mistake.