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AEP’s Energy Storage Delusions

October 22, 2019

By Paul Homewood


h/t AC Osborn/Patsy Lacey


AEP gives yet another plug for Highview Power’s cryogenic energy storage system. (That’s the third time at least)

Unfortunately, again he shows his ignorance of energy systems:


The article is behind the Telegraph paywall, but AEP claims the technology could help plug the intermittency gap as the UK doubles down on its new role as world leader in offshore wind power, and compares the costs of it favourable against small scale peakers.

However, what he misses is that peakers and conventional storage systems only operate for a few hours a year, to cope with spikes in demand and sudden fluctuations in supply.

They are not designed to supply power for days and weeks on end, when wind output is low. For that you need a large scale source of dispatchable capacity, such as CCGT.

If he had bothered to check Highview’s own website, he would have known this, as they talk about balancing services:


 Note also, the £8m coughed up by taxpayers!

They also compare their system with pumped hydro, and indicate that typically the plant could store between 4 and 10 hours of output:



Highview are now proceeding with a new large scale plant rated at 50 MW/250 MWh, which is tiny in comparison to what is actually needed to back up wind power.

With 75 GW of wind capacity projected for 2050, daily wind output would be about 810,000 MWh, and realistically you would need standby to cover for at least two or three weeks. You would need 3240 Highviews just to cover one day’s output.

Yet AEP claims:

Highview is building four much larger  “gigawatt-scale” plants in Texas over the next two years with the US energy group Tenaska Power. Mr Cavada said this cuts the cost “way below” $100 per MWh (£77). The target is to reach $50 within a decade. These sorts of figures – if achieved – would render fossil baseload power superfluous.

I suggest he goes away and does some sums.

  1. Curious George permalink
    October 22, 2019 6:28 pm

    The notion of “bloody optimists” comes to mind. But these guys siphon money from my pocket.

    • johnbillscott permalink
      October 22, 2019 7:06 pm

      I think “shysters”

  2. October 22, 2019 6:37 pm

    Reblogged this on Climate-

  3. John Palmer permalink
    October 22, 2019 7:13 pm

    He must have shares in whoever makes Koolaid!!!

  4. Joe Public permalink
    October 22, 2019 7:17 pm

    “Our large scale, long-duration technology can be built from 10MW to 200MW+ power output, with a storage capacity of 40MWh to more than 2000MWh+. This is high powered energy storage with true long duration…”


    One has to wonder how they would describe the Aldborough gas storage site?

    Its storage capacity is 3,300,000MWh, at a discharge rate of 18,333MW – i.e. 440,000MWh per day for a week.

    Page 149 here:

  5. Iain McPhee permalink
    October 22, 2019 8:15 pm

    I saw the AEP article today and was immediately struck by the lack of detail (ie none!) re duration of power supply from the battery. More fanciful reporting and economy with the truth.

  6. Ray Sanders permalink
    October 22, 2019 8:24 pm

    Is it just me or is there some sinister undertone to the name “Ambrose”. Here we have Ambrose Evans-Pritchard whilst here we have the even more incompetent Jillian Ambrose on exactly the same subject
    Just too spooky eh?

  7. Bruce of Newcastle permalink
    October 22, 2019 10:13 pm

    So if coal fired electricity costs about $25/MWh why would you pay even $50/MWh to store intermittent electricity just so you can use it when you need it?

    It’s not as if anything much is happening climate-wise. No increase in extreme weather like hurricanes and tornadoes for two decades, no increase in global temperature in that time except for three back-to-back el Ninos, no decrease in snow cover extent. If anything there’re signs of cooling, after bad harvests across the northern hemisphere this year.

  8. john cooknell permalink
    October 22, 2019 10:31 pm

    There is always a ready market for Bullsh*t.

  9. Nancy & John Hultquist permalink
    October 23, 2019 4:16 am

    If one wants to store energy, a great big pile of coal works.
    Have a look at this old postcard. The building on the right was the coal shed.

    Potential for flooding and/or ice on the Ohio River caused them to maintain a 360 day’s supply of coal to pump water.

    • October 23, 2019 12:05 pm

      Great reply. When I was a child we had a coal furnace. Where the window and coal bin were in the basement is now where the washer and dryer sit under an enlarged window. A gas furnace replaced the coal one in the 1950’s.

      President Trump has rightly and wisely said that coal is important for national security. Pipelines can easily be severed causing long delays in the delivery of natural gas, etc. Your postcard caption illustrates the wisdom of this in that it is not as easy to deal with piles of coal. .

      • Nancy & John Hultquist permalink
        October 23, 2019 5:15 pm

        Your coal-to-gas childhood was the same as ours, although I no longer live in western Pennsylvania coal country.

      • October 24, 2019 12:32 pm

        Nancy & John Hultquist–I am heading up to Meadville on Sunday after a Daughters of 1812 meeting at the Carnegie Library in Pittsburgh. On Monday it is over to Titusville to give the ledgers of the Brawley Brothers who were in the early oil business to the Drake Well Museum Research Library. They were my great grandmother’s brothers. I have wanted the 9 ledgers to go to an oil museum in that area with an active research library so that they can be used. It turns out that the librarian there is a WVU graduate. My father’s family was all from Meadville beginning with Robert FitzRandolph who came in 1789 after serving in the Revolution on grandfather’s side. James Brawley (my 1812 patriot) came in 1798 and was a constable and justice of the peace. His grandson’s were the Brawley Brothers in oil. Several went to Seattle and were involved in land out there in the late 1800’s.

      • Bertie permalink
        October 25, 2019 11:06 pm

        Joan Gibson
        You are bringing back memories of my, all too short, time when I lived in Pittsburgh.

  10. Steve permalink
    October 23, 2019 5:55 am

    How does this work out for energy in energy out compared to pumped hydro?

  11. October 23, 2019 7:04 am

    “I suggest he goes away and does some sums.” I suggest he goes away and reads the work of the late Professor Sir David MacKay (if he can understand something techncal).

  12. Hugh Sharman permalink
    October 23, 2019 7:20 am

    Highview’s round trip efficiency, the last time I looked, was around 50%. This much is simple physics. It is the main reason no one has yet bought it commercially.

    • Steve permalink
      October 23, 2019 9:02 am

      Dinorwig is 75% efficient. It might be a better investment of taxpayers millions to use Scottish lochs and lakes. bearing in mind that they produce far to much wind and English money for the landowners.

      • Steve permalink
        October 23, 2019 9:33 am

        In the previous related article Cowboy reckoned that the round efficiency would more like 20%, with more losses for refrigerated storage. Questions need to be asked.

      • It doesn't add up... permalink
        October 23, 2019 9:53 am

        It will depend on how long the period of storage is since there will be inevitable heat leakage. I suspect they are assuming a daily cycle length in their figures.

    • It doesn't add up... permalink
      October 24, 2019 3:28 pm

      I think they ignore the “free” heat from some exterior source like a neighbouring power station used to regas the liquid air in calculating round trip efficiency. That’s how you get perpetual motion machines of course.

  13. Richard West permalink
    October 23, 2019 8:48 am

    It doesn’t actually store any energy either… liquefying anything involves the removal of large amounts of energy. What it does it provide a means to allow the upgrading of low grade heat (either reject heat from an existing thermal process, or from the air) into something useful (electricity), and the ability to soak up ‘excess’ energy when available in the liquefaction process, but this, plus the energy removed from the liquefaction process, is then rejected to the atmosphere. All smoke and mirrors as usual….

  14. bobn permalink
    October 23, 2019 10:37 am

    We recently debated the Brexit party’s standpoint on climate. I argued that they were avoiding the subject for now. Here’s Nigel interviewing an extinct rebel nutter. I think we can see he’s still firmly in the skeptic camp but being very political about not getting tied down by the issue.

    His views are more rational than those of any other UK Party leader.

  15. It doesn't add up... permalink
    October 23, 2019 12:08 pm

    The designs that Highview are promoting tell us most of what we need to know. The system is designed to provide only a few hours of storage for several reasons:

    If the storage can be cycled daily, then it has 365 opportunities a year to make money: bigger stores can only be cycled fewer times (and seasonal stores just once per year), raising their effective cost of energy redelivered.

    In a daily cycle you have to allow for the time taken to charge up the system, which will be of the order of the discharge time divided by the round trip efficiency (excluding “free” regas heat from the calculation of efficiency). You also need to be sure that there is a margin between the cost of the energy used to charge the system and the value obtained for energy supplied, limiting charging to off peak hours.

    Longer periods of storage may be technically feasible, but heat leakage will eat into effective efficiency, requiring the system to be topped up with additional cooling.

    As Paul points out, the storage requirements for avoiding wind farm curtailment soon look puny. At 1.2GW, Hornsea wind farm could only store a sixth of its output into a 200MW/1.2GWh system for six hours overnight at times of strongish winds. It has no incentive to do so when it can secure prices of over £200/MWh for curtailment instead.

    This technology reaches a new benchmark for a levelized cost of storage (LCOS) of $140/MWh for a 10-hour, 200 MW/2 GWh system.

    So long as you have 10 hours a day of off peak cheap electricity, and a guaranteed daily price cycle margin that allows you to compete at $140/MWh. Dinorwig mostly has to survive on much lower peak prices, and on average uses only about 70% of its 9.1GWh storage capacity per day. Of course, there are other services that can earn revenue. Although it’s not new (October 2016), this paper by David Newbury does give some useful background on storage options and the competition from flex generation and interconnectors. It doesn’t consider a high renewables world, when interconnectors may prove to be more damaging than helpful, by creating a wide market during energy shortages (with a threat of widespread blackout) and therefore extreme peak prices, and during major surpluses when prices could go strongly negative.

    Click to access 1626-Text.pdf

  16. MrGrimNasty permalink
    October 23, 2019 12:38 pm

    It’s like the game changer battery/fuel cell developments that are just appeals for ‘investment’ (mugs or the tax/bill payer) – gives the inventor a paid job whilst he wanders up another probable dead end.

    There’s bound to be some insurmountable problem, like controlling the output, or producing the cells takes more energy than they produce, or they can supply volts for ages but no actual oooomph on demand.

    It doesn’t matter how many lemons you hook up – it’ll never power a car adequately!

    • Steve permalink
      October 23, 2019 1:26 pm

      There is plenty of information about these aluminium batteries and this particular cells look interesting. The problem is that the battery has to be recycled and the energy and processing cost is going to be similar to petrol per mile including tax. It solves the range problem and would make electric vehicles much more popular but the government loses the tax and it would be necessary to have as many recycling exchange stations as for petrol.

      • MrGrimNasty permalink
        October 23, 2019 4:45 pm

        There’s loads of info about most of the supposed ‘game changers’, they always end up being non-viable. You can’t defy the laws of physics and the principles of economics.

    • Bruce of Newcastle permalink
      October 23, 2019 10:48 pm

      They are single use batteries. Can’t be recharged. So the cost will be enormous, as they have to be changed out. Big sunk capital and large logistic costs carting batteries around for millions of vehicles.

      Even on a direct comparison basis the cost is quite a lot higher than gasoline, since aluminium has only two thirds the energy density of petrol and costs relatively a lot more (though maybe not in the UK where taxes on petrol are huge). On local Australian petrol prices aluminium was about A$81/MJ vs about A$41/MJ for petrol on a quick calc I did a few days ago.

      Also the chemical reaction for aluminium production is:

      2Al2O3 + 3C = 4Al + 3CO2

      The carbon comes from consumable anodes. For every tonne of aluminium they are producing 1.2 tonnes of CO2. So there isn’t even a justification for it for addressing climate change.

  17. Gerry, England permalink
    October 23, 2019 2:22 pm

    This was in CityAM along with a few other ignorant global warming related pieces by the same writer. Seems they have some new boy who trawls up this sort of drivel.

  18. MrGrimNasty permalink
    October 23, 2019 5:19 pm

    It’s only ickle, but Toto is the latest player to find that the competition in the energy market is only pretence.

  19. Ben Vorlich permalink
    October 23, 2019 7:13 pm

    I listened to a BBC correspondent waxing lyrical about this I just stopped listening. Probably Harrabin could have been radio or TV as I tend to listen to the TV.

  20. Athelstan. permalink
    October 23, 2019 9:58 pm

    I’ve suspended belief.

    Next problem, how do I, indeed; how do we manage to survive when, we all live in Disney lala land?

    • dave permalink
      October 24, 2019 10:24 am

      “La La Land.”

      That was a dreadful film wasn’t it? It had the standard Hollywood BS, that is peddled to the masses, that luvvie parasites are the epitome of civilization.

  21. Iain Reid permalink
    October 24, 2019 10:42 am

    My view is that storage can only be beneficial if the source of power is renewable and in excess of demand from the point of view of a reduced CO2 scenario. From my daily visits to Gridwatch website, we never have an excess of wind and solar, excepting that in Scotland that requires constraint from time to time.
    Therefore, all storage schemes will use gas power to replenish the store which rather makes it both very uneconomical and increases CO2 emissions.

    Or have I missed something?

    • Frank Everest permalink
      October 28, 2019 11:05 am

      You haven’t missed anything! Let’s do a back-of-the-envelope sum, ignoring charge/discharge efficiency:

      Suppose we build a wind farm, and hook it up to a huge battery. How big must the turbines and battery be, so the combination has the same delivery capability as a 1GW nuclear station?

      If the wind farm has a 50% service ratio (i.e. the wind doesn’t blow for 50% of the period of interest) then it’ll need to be rated at 2GW so it can supply 1GW to the grid and 1GW to recharge the batteries during windy days. On still days, the batteries will need to supply 1GW continuously (it’s a nuclear power station substitute, remember?). If the wind doesn’t blow for a day (24hours), then the battery will need to hold at least 24GWh. A week, and it’s 168GWh.

      If it’s a day’s worth then, on day two, the battery’s empty and the lights will go out.
      The size of the battery for realistic nuclear power replacement is, by any stretch of the calculation, HUGE. And the cost? Don’t go there!

  22. Dibnah permalink
    October 26, 2019 10:16 am

    Only nuclear and coal can provide long term energy security for the UK. During the miners’ strike in the early 1980s, Drax coal-fired power station had approx 20 weeks of coal stored.

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