Some thoughts on energy storage

A lot of the discussion of my last post on energy issues was devoted to discussion of energy storage. Rather than get involved in that, I thought I’d collect my own thoughts on this. Broadly speaking, Here are some observations, labelled for convenience and partly derived from this study by the US Department of Energy

(a) Any reversible energetic process represents a potential storage technology. Reversibility entails that some energy is stored (as potential or chemical energy) when the process goes one way, and released when it goes the other. Of course, the Second Law of Thermodynamics implies that we will always add entropy (that is, lose useful energy) in this process
(b) Any technical or social change that shifts the time at which energy is finally used replicates the effects of storage
(c)Energy storage is in much the same position as renewable electricity generation was, say, 15 years ago.
(d) There are a lot of potential approaches, most of which have been developed in niches where particular characteristics are required. For example, car batteries need to store a lot of energy for given weight, household batteries need to store energy for a long time and so on. The needs of a renewable-dominated electricity system are very different and will require substantial modifications of these technologies
(e) With one big exception, there is currently no price incentive, in most jurisdictions to use storage technologies and therefore none are used
(f) The big exception is off-peak hot water. Coal and nuclear systems generate baseload supply when it is not needed for consumption. Price incentives are used to encourage people to store the resulting excess energy in the form of hot water
(g) There’s no technological obstacle, given the availability of smart meters, to changing the timing of hot water systems to reflect actual availability of excess electricity rather than reflecting the assumptions of a coal-based system
(h) All of this applies to electric cars. Even ignoring the possibility of feeding power back into the grid, the economics of electric cars would be drastically improved if they could be charged using low-cost power in times of excess supply (in the case of solar PV, around midday when lots of cars are sitting in parking lots)
(i) Something I just found out from the DoE study: Electric car batteries are considered unfit for services when they fall to 80 per cent of their original charge capacity (recall that energy density is critical for car batteries). But they still have a long potential life as static storage devices. This enhances both the economics of electric cars (since the battery has resale value) and of storage (since the opportunity cost is zero)

Here’s an older post, with a really simple example of how the argument works, once you get away from the fixation on replicating the characteristics of a coal-fired system.

107 thoughts on “Some thoughts on energy storage

  1. I’d like to see some comments on the interaction of all this with complications caused by the most cost efficient energy storage system of all – oil in all its variations.

    I may have put this link up before but I’m throwing it in again as its pertinent and for those interested in energy and economics issues who haven’t seen it. The link accesses about 10 very readable review 20 page articles from Dec 2013 the Royal Society rich in meaty statistics outlining the thorny issue of Peak Oil a couple of which are free view:

    This collection is directly relevant to John’s points h) and i) because the overall picture painted suggests it will be hard to move away from petrol as it will not become unaffordable (in contrast to Dick Smiths notorious $10 per L) though it will remain expensive promoting hybrid engine technology and gas use and probably scupper pure electric/battery vehicles.

    An indirect outcome it this will make the already powerful energy giants like Exxon and the Kochs who work on the engineering side even more insanely economically powerful as more resources are directed into extraction activities – providing them with incentive to do more of what we have seen so far like climate change denial, greenwashing and promotion of really rotten energy sources.

    Another interesting indirect relationship – how much oil there is obtainable by one means or another and how will that impact on the whole rationale for storage technology – reducing CO2 emissions? My reading is that even if coal use can be reduced emissions will be rapidly be replaced with oil /gas (the demarcation is being blurred) emissions due to the increasing energy and emissions costs arising from extraction.

  2. Typos: 15 years *ago*, resale *value*.

    I don’t understand point (i) — does that mean that older batteries would be removed from electric cars and used for static storage?

  3. @Newtownian

    I agree that oil is a huge problem. I think that with a combination of carbon prices and technological advances we could see the cost of electric vehicles fall fairly quickly to the point where they are competitive with oil at $100/barrel or less, which would imply that currently marginal sources of oil would cease to be profitable. Otherwise, the best hope is a charging technology in which EVs play a central role in storage.

    For the moment, though, stopping coal is a higher priority both because there is more of it and because the substitutes are more cost-competitive.

  4. The converse of hot water storage is storage of ‘coolth’ such as ice or more exotic phase change materials. If certain forms of realtime electricity generation are disallowed then the amounts required could be staggering. A chilly night in Melbourne might need say 4m X .5 kw X 12 hours = 24 Gwh far far beyond the capacity of any existing electrochemical or battery system. On other posts here someone has suggested that lithium ion batteries cost 50c per kwh over their life cycle. That’s $500 per Mwh or $0.5m per Gwh. In the Melbourne example the cost would be $12m for one night.

    Another proposed form of energy storage is synthetic methane kept in gas pipes and used to run jet turbines during lulls in other energy sources. The methane is made from hydrogen from water splitting and waste CO2 from industrial processes. The round trip efficiency is under 40% but may scale to Gwh level or at least the Germans think so.

    The California Air Resources Board suggests a target of $40 per Mwh storage on top of generation and transmission costs. The previously mentioned lithium battery figure is $500.
    The AEMO report on 100% renewables looked at some possible new sites for pumped hydro storage and was less than positive. When the water level in a dam quickly rises and falls by several metres a day that creates silting. Also tough on aquatic life.

    It seems like we’ll need a lot of dispatchable realtime generation matched to established demand patterns. As for battlers driving electric cars I’ll believe it when I see it. There will still be times when realtime generation is needed.

  5. All good points in JQ’s post and in the other post linked to.

    Running stationary energy generation (electricity) without coal will be eminently achievable in Australia. This is made clear with the economic, energetic and materials analysis at the Zero Carbon Australia website. (Disclosure: I have no connection whatsoever with this group. I read their website as a lay member of the public.)

    I do not know if running stationary energy generation (electricity) at current or improved levels without coal will be achievable globally. Clearly, the scaling up problem (materials availability) will be much greater for the whole globe and not all countries have such ample land and all-year-round solar radiation and wind assets as Australia does.

    Concern about energy storage problems (for electrical power generation) are exaggerated. Solar convection towers, whilst not as efficient as PV in the daytime can provide power 24/7 and thus obviate much of the need for night storage. Very likely, solar convection towers, whilst dearer than PV per unit power delivered, will prove to be more economical than mass energy storage solutions like molten salt tanks.

    Distributed, hybrid electricity generation systems (mixes of PV, wind, solar convection, solar concentrating, molten salt heat storage etc.) are likely to prove much more robust and dependable overall and less prone to massive breakdowns, meltdowns etc. than is the case with nuclear power for one. This is important even if they are not cheaper. Greater robustness and dependability at about the same price or even a little more cost is still a valuable outcome.

    The dependence of our transport and industry on oil and oil products is a whole other issue and one much harder to deal with. The decline in ore concentrations in mining and the concomitent need for ever greater energy inputs to obtain these metals (common and rare) is also a looming issue.

  6. @ Ikonoclast when push comes to shove will people willingly pay more for expensive energy? I’d say the last federal election was in effect a referendum on that. It’s actually gotten worse because Joe Public is now looking the other way as World Heritage areas get trashed for the sake of some quick dollars.

    A quick way to look at Ted Trainer’s rebuttal of ZCA is to search for his articles on the BNC website. His major point is that even if a predominantly renewables system could be afforded there is an additional staggering cost of power stations only needed for critical downtimes. For example a continent wide high pressure system with cloud cover. ZCA lost me with the electric trains delivering hay bales to the backup power stations and the ‘voluntary’ 50% reduction in overall energy consumption. We need even more energy for electric transport, ways to cope with heat waves, desalination and for our 0.4m new Aussies each year.

    I accept that nuclear cannot play much of a role for another decade. Some opine that the Russians and Chinese will grab the market while the US is navel gazing. From what I can see the coal guzzling satanic mills in the Hunter and Latrobe Valleys will be with us til the 2030s. With or without RET, Direct Action, carbon tax etc I see little alternative.

  7. @Hermit

    Ted Trainer is neither an economist, nor an engineer, nor a quantity surveyor nor a scientist (in any of the hard sciences). So I would not regard Ted Trainer as an authority in these matters. The fact that Ted is writing on (featured on?) BNC is even more cause for concern. BNC is a nuclear power apologist website with a track record of lying and fabricating to minimise to deny very valid concerns about nuclear power.

  8. @Hermit

    Seconding Ikonoklast, and having engaged in detail with Ted, I can say that his heart is in the right place (he’d really like a sustainable, low-consumption, society where everyone is nice to each other) but, as an energy economist he makes a great social work academic (his actual job)

    And the fact that he’s prepared to post on BNC, which is antithetical to everything he supports (or used to), shows that he has let his anti-renewable dogmatism override his judgement in every way.

    I don’t endorse the view that BNC in general lies about nuclear power (at least now that Peter Lang is gone) but they have shown themselves to be entirely unreliable even on technical issues (for example, Barry’s “nothing to worry about” posts on Fukushima). As regards economics, I’ve never seen a BNC analysis that didn’t contain major errors in every paragraph.

  9. I once ran some numbers on hydrogen gasometers feeding into [reversible] fuel cells: doable, but the energy density of low-pressure hydrogen too terrible for words.

    Other fuel-cell chemistries might work better, though. A fuel cell essentially separates out the “reaction vessel” and “containment vessel” functions of a normal chemical battery, which imposes limits on the reactants [none of them can be solid] but offers some other pretty obvious advantages. I think someone suggested Fe2+/Fe3+, which might work interestingly. Not my field, of course.

  10. @Collin Street

    I cannot understand the fuss about hydrogen fuel cells. Producing free hydrogen takes a lot of energy (from other sources of course). Hydrogen is devilishly hard to store, transport and has a low energy density per volume. The hydrogen fuel cell will never suit bread and butter energy applications for transport or anything else. Hydrogen fuel cells may have specialist applications where their particular characteristics are useful and cost and standard safety and convenience are not so much the issues.

  11. Australia is in a fairly unique position in that because of high retail electricity prices and generally low feed in tariffs for new rooftop solar, it may become profitable for people to install home and business energy storage. Something that would prevent this, a decrease in retail electricity prices doesn’t seem likely to happen any time soon, although I suppose it is possible that tens of billions of dollars could be taken from people in general and used to pay off bad investments in transmission infrastructure. While that would be popular with a number of people, the whole taking tens of billions of dollars from people in general and giving to a much smaller group of people who are on average richer than the people the money is taken from may make it unpopular and so unlikely. An increase in feed in tariffs for rooftop solar would also discourage energy storage but that that doesn’t seem likely in the short term either. We know from other nations’ experiences and even from a weird place called Victoria that it is not especially difficult to have people pay a price for electricity that reflects the cost of supplying it at the time its used and all else equal this would definitely encourage home and business energy storage in Australia. So if rooftop solar continues to expand, and grid electricity use continues to decline, and the retail cost of electricity continues to rise to pay off under used transmission infrastructure, then it looks like we’ll end up with a considerable amount of home and business energy storage, some of which, or a large part of which, may consist of the battery packs in electric cars. I don’t know how likely it is that something will happen to prevent people putting energy storage in their homes but to me the chances of home and business energy storage taking off in Australia seem high.

  12. One of John Quiggin’s main points is that matching energy production to use or use to production is better than energy storage. There are further energy losses in storing energy as heat (molten salt heat storage) or as potential energy (pumping water back up to the dam in a hydro power system) and converting it to electrical energy later. Changing pricing systems will facilitate the necessary changes in generating regimes.

    When it comes to electrically heated hot water, the hot water is the energy storage as mentioned. However, one would hope as a minimum, all houses in Australia would get solar hot water systems even if they do not get Solar PV. Then, the only electrical heating would be the back-up elements.

    One would think that central energy storage (when needed) would be more efficient than scattered storage at home sites. However, many practical considerations do suggest some considerable home storage will exist. Hot water systems and car batteries are two good examples which have been mentioned. People who want battery back-up to blackout proof their homes will be another group along with people who go off-grid by choice or necessity.

    There is probably a lot more that could be done. In my general area, a suburb or two away, there is a light industrial estate where a molten salt heat storage tank and associated electrical turbine generator could be safely sited. People like me with a spare acre or two could farm solar power easily enough and sell it to the storage facility. Or even lease part of our land on 20 or 30 years leases for them to put the solar PV panels in.

  13. (c)Energy storage is in much the same position as renewable electricity generation was, say, 15 years ago.

    Granted you can shift some demand with price signals. However the intermittent nature of renewable energy and the lack of storage commercialisation means that programs like MRET are simply forcing us to adopt expensive, immature solutions. The mandates should be pulled back and technological development allowed to run it’s course.

  14. Note: Programmable inverter-charger systems are now available for homes (with attached Solar PV and battery bank of course). These systems;

    – “Can calculate the total consumption of household electrical appliances and direct electricity accordingly; and
    – Maximise savings on the power bill of the home by utilising electricity on ‘least cost’ priority basis (namely: solar panel array, battery, grid depending on the time of day and the customer’s metering/billing arrangement).”

    I assume these systems can also power a home during a blackout by “islanding” the home from the grid and using solar power / battery power directly in the home.

    I imagine such systems would be quite costly and could currently cost $30,000 to $40,000 for a home. (That’s just a guess.)

  15. If nukes can have a meltdown then so could molten salt tanks in the suburbs, or at least they could rupture and the nitrate contents would oxidise surrounding metal and vegetation. Could be why they are mainly in the desert. Perhaps they’d need a containment vessel like a nuke. Same goes for sodium sulphur batteries and ceramic fuel cells burning gas – they all run at high temperature.

    The problems with home batteries are the initial cost, replacement cost and the bulk issue for small properties. With the smaller lighter lithium batteries inevitably some would catch fire, recent examples being the Tesla and Fisker electric cars and the Boeing Dreamliner aircraft. The price of grid power during winter and rainy weeks is likely to increase due to lower utilisation in fine weather ie to recoup the fixed cost with fewer units.

    Will home batteries and electric cars even make it to 1% penetration by 2020? I’m sure Hazelwood power station will still be spewing 14 million tonnes of CO2 in 2020.

  16. @TerjeP

    I take issue with the emotive and inaccurate verb “forced”.

    Are we being “forced” to adopt or “induced” to adopt? Individually, we are being induced to adopt by incentives. Nationally, we are being “self-directed” to adopt. A democratic government made the decision essentially via the vote, direction and demand of the people.

    However, I accept the point that we could theoretically be pushing too fast. In practice, it’s a complex feedback loop. Pushing “too fast” pushes the technological progress and soon “too fast” becomes the appropriate pace.

    I guess libertarians don’t like it when government action is shown to be effective at least sometimes. 😉

    Note: Even I don’t think government action is always effective or always the best way to tackle problems.

  17. @ John Quiggin:

    “The economics of electric cars would be drastically improved if they could be charged using low-cost power in times of excess supply (in the case of solar PV, around midday when lots of cars are sitting in parking lots.”

    Hmm. Electricity storage with car batteries would work a lot better with a low-carbon baseload generator like nuclear than with PV. Yeah, there’s a dip in driving at midday compared with rush hour, but there is still much more driving and electricity use at mid-day when solar PV is generating than at night when nuclear plants are still going strong. So it makes sense to store energy in auto batteries at night when cars and electricity are both in much less demand than at midday.

    The key to efficient and economical energy storage is to store when demand is low and sell when demand is high. Nuclear complements that storage profile better than PV. And of course on cloudy days there will be virtually no PV storage period.

    Dispatchable renewable technologies like hydro, geo and biomass also store well because storage yoked to those generators can reliably save up electricity during offpeak hours to sell during peak demand. But intermitten wind and solar are chaotically unreliable, so they don’t fit well with any kind of storage.

    We’re seeing this now with pumped hydro in Germany. Pumped hydro is the main form of grid storage—your DOE document put it at 23 GW in the US, which is 95 percent of all US grid storage—and it’s always cooperated profitably with baseload generators. But the flood of solar in Germany is crushing the economics, because it overproduces in daytime hours when pumped hydro makes its money while generating no electricity to store during periods of low night-time demand. PH stations are starting to lose money, and will be cut their own slice of subsidies to stay in business (or be replaced by more carbon-powered generation).

    Storage is a way of fitting electricity supply to variable load. That problem gets dramatically harder and costlier when intermittent wind and solar generators, whose outputs vary much more than the load itself, are introduced into the equation.

  18. I agree with RB’s take on this. Domestic energy storage has an available cost inefficiency factor of 4 , five cents energy cost for grid to retails 20 cents per unit. Domestic energy storage users can cope with significantly higher costs than a grid based storage entrepreneur. And there is the very real opportunity for a battery rental service to operate in this field, and I think that this would be far more successful than the battery exchange for electric cars that have turned up too slowly to create a viable business.

    The battery rental business would well suit a battery manufacturer or distributor who could benefit from batteries manufactured specifically for the home energy market, and provide wheel in wheel out storage capacity for changing user needs. In fact the concept is suitable for people who don’t have solar panels but are stuck with smart meters and time of day billing as millions of UK users are soon to encounter. Fix? Charge batteries during off peak and consume during excessive billing periods. Not a new idea, even Fran Barlow suggested this some years ago. It is something that I am seriously considering for my petrol supplies now that they, the petrol retailers, appear to think that a cyclic 40 cents per litre variation is in their best interests.

  19. I take issue with the emotive and inaccurate verb “forced”.

    You can take issue if you wish. But given the way MRET works I would think “forced” works just fine. You can use the word “induced” instead if you prefer and I will still know what you mean.

  20. TerjeP,

    You are always out to save a buck.

    I bet you impatiently change queues at the supermarket to try to get to the counter sooner. Technological development requires consumption for efficient and evolving market support. A clever guy such as yourself should know that. So your comment is really that you would prefer that renewable energy technologies starve to death through lack of interest, as this supports your denialist expectations on climate change.

    The fact is that had home power generation not been specifically legislated against for decades we may very well have had much of this technology a lot sooner, and without any nudge from the government.

  21. Tom Murphy’s Do the Math links
    Got Storage? How Hard Can It Be?
    A Nation-Sized Battery
    Pumped Storage“>Aquion has started production of a low-cost sodium-ion battery…
    There was some stuff on Iron air batteries for static storage too.

    Pumped storage or the <a href=""electric railway variant need mountains with height, a problem for Australian conditions.

    Ice storage air conditioning?

    Phase change materials in plasterboard to increase the thermal mass in hot weather.

  22. @Will Boisvert

    Will is such a busy pro-nuclear propagandist one would have to form the opinion he is paid to do it, probably full time. There is a word for that and it rhymes with “Will”.

  23. 50cent per kwh for lion battery storage is far to high, before factoring in any technological process. Maybe its about right for some microscopic niche market home pv/battery store systems, but the costs dont add up with current battery prices and rechargeability. Standard battery prices are below 200 dollar/kwh. Alas, the solution for electric cars on the long run is unlikely to be the Tesla route. Rather well see 5000 time rechargable batteries that cost somewhat more (current prices).

  24. I bet you impatiently change queues at the supermarket to try to get to the counter sooner.

    What’s the hurry? The queue provides time for quiet contemplation.

  25. @David Irving (no relation)

    Wow, that is cheap, all things considered. If that is for good quality equipment (not market’s cheapest and worst practice) then it seems good value. I would have found it hard to believe that all that could be got $17.5K. But then I can find 6KW max, 5KW continuous diesel generators for $1,199. Good brands too. That really amazes me. However, I assume you would need another 2.5K for a good solar hot water system as well, so $20K in round numbers.

    A potentially 2 car or 3 car family could forego one car and get such a system. It would be a darn good investment in my book. Much better than another car.

  26. Picking up the use of traction batteries for home storage, you can do that now but using lead-acid batteries from industrial machines rather than liion ones from cars. As suggested, they are currently recycled when they’re down to 70%-80% of capacity, because an electric forklift that only works for half a day is effectively useless. Those batteries can be “rented” for not much more than the cost of delivery and pickup because the recycling process doesn’t care particularly what condition they’re in. The problem is that they’re only really available in the major cities, when most off-grid users are remote. For remote users, obviously, the cost of transport means than an annual battery swap is more expensive than buying purpose-designed batteries.

    The major problem is that they do lose more energy than propose-designed batteries, because like car batteries they’re optimised for high power output rather than low electrical leakage over long periods.

    But if you are in a city and looking for storage, I suggest giving your local industrial battery recycler a call (25 years ago we were paying ~$50 for a battery swap for a 50kWh battery that was down to ~35kWh. We paid $500 for the first battery, but after that just the pickup/delivery charge.

  27. Again good luck with getting a 7-10 kw PV array in the suburbs, perhaps a small wind generator, a shed with 10-20 kwh of lead-acid or nickel-iron batteries and perhaps a backup diesel generator. As soon as the neighbours perceive their TV flicker or dodgy mobile phone reception is due to the propellor or you run the diesel at 10pm in the winter then they will no longer be friendly.

    Due to reduced incentives uptake is now tapering off strongly for grid connect PV…see the graph in the solar boom article on the DSA website. Enthusiasts for home batteries will need to turn this around. That suggests even if batteries can repeat the 80% cost reduction in the panels current economics will not spur people to go off-grid. As I suggest going off grid in the suburbs could also create tensions.

    Having said that I have run a deep cycle PV charged lead acid battery for 9 years without problems. It merely needs the electrolyte topping up. The current application is powering a 12v LED light in a cellar, that is low current draw and not inverted to 240v AC, hardly in the same league as running a vacuum cleaner or rotisserie oven. My prediction is that serious home batteries (10 kwh+) will not go prime time, say 1% of homes by 2020. Think of something else.

  28. @Hermit

    I didn’t think the aim was to mass convert people to full-on RAPS system in the suburbs, more observing that as the cost of grid electricity rises and feed-in returns drop, at some point it will be worth while for suburban house-owners to go off grid.

    A lot of houses are grossly oversized with correspondingly large roofs. As the cost of PV falls the gap between total consumption and the output of an affordable array keeps dropping. Similarly, the cost of batteries and so forth is also dropping, but more slowly. Which means that going off grid would save some people money, even people who have grid access.

    Especially if feed-in tarrifs keep dropping and a solar surcharge is introduced, at which point those people will be saying “why should I pay to supply my neoghbours with electricity that they in turn pay someone else for?”

    Making batteries cheaper would dramatically lower the cost of storage, to the point where even non-generating customers might benefit by switching to a time-of-use tarrif and charging at the cheap rate and substituting the expensive rate with battery power (starting with customers whose peak rate use is low, obviously).

    Personally, one reason we’re saving for a house in the suburbs is because we expect this to be economical for us almost immediately (ie, as soon as we can save enough to add the system). Our consumption is low even in a poorly constructed apartment, and because we’re new suppliers we’re not going to get any feed-in advantage but will likely be buying power at 30c/kWh and selling it at 8c/kWh. With those numbers a battery system could perform very badly and still make economic sense (we could afford losses of almost 75% if the system was otherwise free, for example).

  29. You’re being very negative there Hermit, and that is disappointing from someone who has claimed in the past to be an off grid early adopter of rooftop solar PV.

    Have we lost sight of the fact that the primary interest in renewables has been to reduce CO2 emissions into atmosphere in order to attempt to limit the impact of Climate Change.

    Just because we are not talking about Climate Change so much now does not mean that it has stopped progressing. On the contrary our ever increasing emissions globally mean that Global Warming is being consolidated and the consequential climate impacts will continue to be a horrible surprise for those affected. And an army of scientists with the knowledge to assess the science repeatedly reinforce the inevitability of climate devastation for a recalcitrant civilisation.

    The aim here is to find ways and methodologies to become carbon free, not to club every new initiative to death because it is not a “pure enough” solution to satisfy the climate change deniers and grid energy adherents.

  30. @Hermit

    Currently in Brisbane and environs, I believe one would be permitted a 5.5 kW nominal or nameplate system which would rarely feed in more than the permitted 5.0 kW. This would be the case unless your suburb was already saturated with solar PV to the local capacity. (Note: I have seen my 5.5 kW nominal system achieve 5.2 kW in practice).

    A shed of batteries should not be a problem. One commercial operator in Qld states “Our power utilities such as Energex, Ergon Energy and Essential Energy allow battery backup systems in the event of electricity grid failures.”

    I doubt one would consider or be permitted a significant wind generator on a 1/4 acre block. I also doubt you would need it.

    Diesel generators seem to spring into use at some houses on acreages during blackouts. Not sure about the 1/4 acre block though. Your neighbour would probably accept it on a 1/4 acre block if you let him / her plug a fridge and a TV into your board during a blackout and didn’t run it at other times. But I wouldn’t bother with a diesel generator. Seems like more overkill.

    Hermit seems to negative gainsay everything to do with renewable energy and renewable (or non-renewable) back-ups. Not sure why. Something about “won’t magically save us by 2020”. Well, given the lead times on nuclear that wouldn’t even magically save us by 2030 or 2040.

    In the future we will have to cut our coat to suit our cloth. Eventually, only renewable energy will be available. That will mean;

    (a) living on a lot less energy if we can make it work; or
    (b) dying if we can’t make it work.

    Renewable will be workable at some level. That is how the human world was entirely powered before about 1750. Nuclear will fail as fissionable materials fail. A nuclear-industrial collapse would be catastophic. Mass nuclear power stations could not be decommissioned successfully in a world without high energy fossil fuels. Basically, they would go into meltdown one by one as they fell into neglect and as a partially de-industrialsed society simply could not cope with them. Decommissioning is a highly energy intensive and complex process. Complexity collapse would leave society without the energy or expertise to decommission nuclear power stations.

    The renewable path is much safer and allows a safe power-down of society to the renewables level (barring excess conflicts).

  31. I am wondering whether it would not both more cost effective and efficient to develop local communal grids rather than base solutions on individual households. There are costs involved. Surplus energy generated by PV’s might gifted to others in the local grid. This is not the outcome at the energy companies will entertain.

  32. Come to think of cities like Baghdad have a lot of backyard generators but I think their stress levels may be higher than we’d like. Diesel generators in the suburbs used more than half an hour a year doesn’t seem like progress to me.

    Re nukes and maintenance. How will wind and solar create the silicon, rare earths, steel and cement needed for their replacement after 20-30 years? Nukes can last 60 years or more and I’m pretty sure getting the replacement materials can be organised with high temperature applications. If we degenerate into a Mad Max society I think our problems will run deeper (eg finding food and fuel) than trying to prise open 35 tonne dry storage casks of spent nuclear fuel.

    My alternative model is France. There electricity is low carbon, reliable and affordable. The people use electricity (induction, microwave, resistive) to cook and heat pumps not gas to heat houses. No concerns over kids sticking screwdrivers into lithium batteries nor of winter debilitating the power source.

  33. Hermit, do you know anyone who thinks installing 10+ kilowatt-hours of energy storage in surburban houses that have access to a functional electricity grid is a good idea? If you don’t, you might find your life easier if you don’t worry about this sort of thing until you meet someone who does.

  34. Moz, using pre-loved lead acid battery packs is an interesting idea and certainly could be a cheap option. I have seen new deep cycle lead acid batteries for sale for under $120 a kilowatt-hour of storage with a five year warranty. If one buys two kilowatt-hours of these batteries per kilowatt-hour of storage used to make up for their drawbacks then that would be a clear money maker for someone who can sell electricity from rooftop solar for eight cents a kilowatt-hour but buys it for 30 cents a kilowatt-hour, if the cost of batteries were the only concern. However, there are installation and electronics costs and I’m not sure just what is the best way to handle them. With lithium ion batteries its fairly easy to include a couple of kilowatt-hours of storage in a solar inverter and screw it to the wall, but lead acid batteries aren’t so convenient. One possible solution would be to have a heavy but compact case that would include a long life inverter and battery management system with a 10+ year warranty on those parts and space for two 3+ kilowatt-hour deep cycle lead acid batteries. It would come with one battery and then as it ages and loses capacity a second one would be bought and intalled. Actually it might need to use several 1-2 kilowatt-hour batteries as a 3+ kilowatt-hour lead battery acid would be too heavy for many people to move on their own. It is possible to buy systems like this at the moment, but they are expensive and the warranties can be really terrible with the electronics having less than half the warrantly length of the batteries. Obviously that is not good enough and is quite sensibly going to put off a lot of people. Another option would be to purchase a solar inverter that incorporates a battery management system and then plug in the lead acid batteries separately. One advantage of this is it would be technically possible for the inverter to handle different types of batteries and people could later replace their lead acid batteries with another chemistry if one turned out to provide better value. I would suggest that some young entrepreneurial Australians create a business designing and building world class technology for home and business energy storage, but our government values small business and entreperneurialship so much it may crush you, so I’m not sure I can recommend that with a clear conscious. It may be better to just wait for Germany to bring down the costs like we normally do.

  35. MeanwhileIsentropic’s pumped heat energy storage system is claiming costs lower than pumped hydro storage – without the geographic or climatic constraints. They claim Levelised Cost of Storage of US$35/MWhr and are building a 1.5MW/6MWh demo plant in partnership with the UK’s Energy Technologies Institute. ETI though it good enough to buy equity to help the pilot project go ahead.

    I don’t think energy storage is the impenetrable barrier that opponents of replacing fossil fuels claim it to be. When coal and oil are cheap and abundant and CO2 is not a counted as a climate problem why bother with it? We are just beginning to discover serious demand for large scale storage and it’s probably going to be met without as much difficulty as the naysayers would have us believe.

  36. @Ken Fabian

    So is Isentropic’s idea “just” a new application for the Stirling engine? A Stirling cycle device can create motion if provided with a temperature difference and create a temperature difference if provided with motion. So they couple a Stirling engine to the (soon to be) hot and cold tanks via the pistons, and then couple the Stirling engine to an electrical engine/generator via the shafts of the engines (through gears or gas turbines). That is my guess.

    Overall, it looks like a good idea. If the numbers add up as they claim then it’s a damn good idea and conceivably safer than molten salt heat storage (which goes rather hotter).

    Energy storage, load equalisation and distributed generation are not the problems the naysayers would have us believe. Yet they would have us believe that nuclear engineering is simpler than mechanical, electrical and chemical engineering. Indeed, nuclear power stations require nuclear engineering, mechanical engineering, electrical engineering and chemical engineering. Thus nuclear power stations have all the other problems PLUS the hardest and most dangerous of all, nuclear engineering.

  37. @Hermit

    There are currently 435 operable civil nuclear power nuclear reactors around the world. To lift the percentage of world electrical power provided by nuclear power from 13% to 65% ( a more France-like number) would take 1, 740 more nuclear reactors. Currently 71 new reactors are under construction so we “only” have to plan and construct 1,669 more nuclear reactors. Does the world have enough suitable sites now we know that;

    (a) they are not safe on coasts (tsunamis, hurricanes, sea level rise) so scratch salt water cooling;
    (b) they are not safe in earthquake zones;
    (c) they cannot be sited anywhere without adequate cooling water (factor in world freshwater shortage).
    (d) they should not be sited near towns, cities, farming land, dams or rivers (dangers of contamination)

    Then there is the very real issue of peak uranium (already peaked).

  38. I ought to add the real situation is;

    “New plants coming on line are largely balanced by old plants being retired. Over 1996-2009, 43 reactors were retired as 49 started operation. There are no firm projections for retirements over the period covered by this Table, but WNA estimates that at least 60 of those now operating will close by 2030, most being small plants. The 2011 WNA Market Report reference case has 156 reactors closing by 2030, and 298 new ones coming on line.” – World Nuclear Association.

  39. @Ikonoclast

    Also, the materials being used to store the heat and as heat sink are relatively inert, common and stable, which is a huge advantage.

    Because the technology promises to be highly scaleable — the prototypes are storing 2-6mWhe — you could scatter the storage easily, scaling it to fairly small distributed energy systems using it not only to ‘firm’ intermittents, but to regularise their outputs to the grid and simplifying integration. If RTEs are 75% as claimed then this makes it an appealing option compared with pumped storage which has some pretty severe scaling and site constraints.

  40. On the required build rate for nukes it could be pointed out that France went on a building spree in the 70s and 80s. Now they have the lowest per capita emissions in Europe and much cheaper electricity than Germany or Denmark. In WW2 planes and ships were cranked out like sausages. While we’re waiting for the US to produce prefabricated mini nukes others could steal a march. For example Asian customers are interested in Russian made floating nuclear plants. We just need a few prefab plants installed on land to get on the learning curve.

    As for peak uranium since we have more than any other country like Middle East oil we should keep a lot for ourselves. We’d be OK til 2050 at least. Fourth generation nuclear could conceivably eliminate the need for uranium mining. For example the UK may get Prism reactors from GE-Hitachi to burn up plutonium stockpiles. There is said to be enough of this one material to power the UK for 500 years. In Australia we’ve also got thorium from beach sands as well as hard rock deposits.

  41. Even, Hermit, all of the above was possible, how would that in any way influence the uptake of rooftop solar PV?

    Why is it even relevent to talk about Nuclear in the same topic as renewables and storage?

    Nuclear is only relevent from a CO2 emissions point of view and would be even more controversial from a government intervention perspective than the MRET is to the TerjeP’s of the world.

    Rooftop solar and complementary energy storage is an energy future on an entirely separate trajectory to the Grid Energy industry. People install their rooftop energy packages to increase their standard and quality of living, and nothing short of a Taliban like government is going to prevent that from continuing. Any suggestion that Nuclear energy is going to be so cheap that no one will use anything else is totally foolhardy. The energy production cost is now the smallest part of the grid energy equation, Energy price constraint is now a thing of the past and the energy distributors are pricing from a “what is it worth to them” rather than a “what is a fair price” standpoint. It is this that will guarantee that most houses and businesses will eventually have some measure of rooftop energy solution.

  42. @Ikonoclast
    PHES is based on Ericsson cycle – which I don’t think has had a commercial application for a long time. I don’t claim to understand how they came up with figures for LCOS or if those numbers will survive commercialisation, but they do claim lower cost than anything currently available, including pumped hydro. It is Electricity In – Electricity Out storage and they appear to be aiming for 3 hrs of storage, as some sort of sweet spot for grid applications. The working fluid is Argon distilled from air and unless in an enclosed space, will harmlessly go back to the atmosphere if it leaks. The thermal storage medium is gravel in insulated steel containers which would be non-toxic and recyclable. I did have a pdf that showed a couple of LNG storage tanks that they claim would be of a size able to store multi-GWhrs – but I’m struggling to find it – or the site it came from. I’ll take another look when I have a bit of time.

    Pumped hydro is unlikely to be expandable much in Australia and I expect the needs of in house water management will take precedence over storage for sale. I think molten salt with thermal solar will have a big future – if or when Australia actually brings itself to commit in a meaningful way to reduced emissions energy. We cannot rely on big Electricity generators to lead the way – they are still foot dragging impediments who still hold out for permanent exemptions to allow ongoing use of coal.

  43. @BilB
    The answer is that PV works best in the middle of sunny days. I suggest that on a year round equivalence basis 85% of the time it is not the middle of a sunny day. At night or in pouring rain you want your appliances to work. Since it can sometimes rain for a week the total energy storage requirement is far beyond the capability of any energy storage facility we have in Australia. I don’t see that changing, perhaps ever.

    To illustrate we know that it is possible to drive a car from Adelaide to Darwin on realtime solar PV. It does not follow that 40 tonne semitrailers or family 4WDs towing a caravan can do the same. Ditto the overall power needs of a modern industrial society.

    On uranium I might mention what I think is an extreme irony. The gaseous diffusion enrichment plant in Kentucky US is to be replaced with something 75% smaller using a laser process. That laser process was conceived here in Australia. Google Paducah + laser.

  44. @Fran Barlow

    On the linked site you provided, several stories relate to US/Canadian weather and the polar vortex. I was in Canada recently and directly experienced the cold east and the warm west (as it was at that time under the influence of the polar vortex). Earlier on, BC and Alberta had been cold until the cold polar stream moved and planted itself in the east.

    The influence of global warming on the polar vortex is that the wavey jetstream (vortex) going round the pole develops larger amplitude waves where the cold front presses further south (in the east now) and the warm front presses further north (in the west now.) Waves with a larger amplitude are slower. This means the high amplitude polar vortex tends to park or drag itself along in one general region for longer. It takes longer for the weather patterns to move east (the natural direction due earth’s rotation).

    A result of this (this northern winter) is that the east of North America gets protracted snow storms whilst Alaska and Yukon are unseasonally warm and drought struck California and Nevada get hardly any snowpack in the Rockies and in Nevada. So a dry spring thaw is in the offing in the west and more drought for those states.

    The tendency of an exaggerated polar vortex to lock in one place longer increases damage from weather extremes in North America. Increasing damage from climate change is already playing out. This is related to the energy storage topic after all. The biosphere is storing more energy from the greenhouse effect. Regions are storing more energy for longer durations or losing it for longer durations during extended climate cycles. Climate change disruption on a wide and measurable scale has arrived.

  45. @Ken Fabian

    Interesting. What is old is becoming new again. I don’t pretend to understand the technical difference between an Ericsson cycle and Stirling cycle heat engine setup. It seems to me as a layperson that the thermodynamic principle(s) and even mechincal designs are substatially the same. Apparently it’s very complicated physics at the theoretical level. Are they variants on a theme to achieve patentability? A lot of that happended in the 19th C too you know.

    Yes, we cannot wait for Big Coal and Big Oil to do anything. They are ossified and non-innovative corporations now. They are placing huge roadblocks in front of necessary progress to renewable power.


    “The Ericsson cycle is often compared to the Stirling cycle, since the engine designs based on these respective cycles are both external combustion engines with regenerators. The Ericsson is perhaps most similar to the so called “double-acting” type of Stirling engine, in which the displacer piston also acts as the power piston. Theoretically, both of these cycles have so called ideal efficiency, which is the highest allowed by the second law of thermodynamics. The most well known ideal cycle is the Carnot cycle, although a useful Carnot engine is not known to have been invented. The theoretical efficiencies for both, Ericsson and Stirling cycles acting in the same limits are equal to the Carnot Efficiency for same limits.” – Wikipedia.

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