[HN Gopher] UK's largest flow battery energised
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       UK's largest flow battery energised
        
       Author : vanburen
       Score  : 55 points
       Date   : 2021-12-20 20:07 UTC (2 hours ago)
        
 (HTM) web link (energysuperhuboxford.org)
 (TXT) w3m dump (energysuperhuboxford.org)
        
       | rkwasny wrote:
       | 5 MWh = 370 tesla powerwalls - for a grid energy storage this is
       | a small POC
        
         | jacquesm wrote:
         | That is true. But the Tesla powerwalls would be using Lithium
         | Ion tech, and that is used here too but 50 MWh worth of it. So
         | the whole installation is considerably larger than what you
         | write.
        
       | gandalfian wrote:
       | 27x 20ft shipping containers combine to form a 5mw vanadium flow
       | battery buffering a 50mw lithium battery. Which is interesting
       | but the fact it's not 100% flow battery suggest lithium must
       | still be sufficiently cheaper to overcome its shorter life.
        
         | ok_dad wrote:
         | > 27x 20ft shipping containers combine to form a 5mw [it's
         | 5MWh, not 5MW] vanadium flow battery
         | 
         | This seems like a LOT of space required for such a low
         | capacity. For a 5MWh flow battery, I wonder what the peak power
         | output actually is from the system? for LiIon, you would see
         | about ~1MW peak power from such a small reserve of energy. Flow
         | batteries are longer lasting, so I assume this battery is less
         | peak output. I am pretty sure that the LiIon battery will be
         | doing the heavy lifting here, sized as it is. This isn't a huge
         | leap forward.
        
       | TradingPlaces wrote:
       | Vanadium flow batteries have gotten lots of interest because
       | vanadium has 4 oxidation states, so the positive and negative
       | electrolyte tanks have distinct charged and discharged
       | chemistries. This adds a ton of flexibility to usage from
       | multiple cycles per day to seasonal storage while the battery is
       | still operating daily.
       | 
       | Manufacturers are advertising 20k cycles vs 6-7k for Li-ion, but
       | in theory, flow batteries can last forever with maintenance.
        
       | jacquesm wrote:
       | This is a very interesting development. 55MWh is a drop in the
       | bucket at grid scale but it definitely is a step forward if the
       | installation performs as designed over a longer period of time
       | without reliability issues.
       | 
       | For comparison purposes, also in the UK, Cruachan Dam has 7+ GWh
       | worth of (pumped) storage, but this one even in its present state
       | should be able to spin up even faster (though Cruachan Dam is
       | _very_ impressive in that respect).
        
       | retzkek wrote:
       | Since TFA didn't really explain what a "flow" battery is:
       | https://en.wikipedia.org/wiki/Vanadium_redox_battery
        
         | yob28 wrote:
        
         | elithrar wrote:
         | > In the ESO hybrid energy storage system, Invinity's vanadium
         | flow batteries are used to 'front-end' the energy asset, acting
         | as a first line of response when the system is called into
         | service; only after the required response exceeds the capacity
         | of the Invinity battery does the lithium-ion battery get called
         | into service. Since Invinity's flow battery does not degrade
         | with use and can cycle indefinitely, it performs much of the
         | 'heavy-lifting' required from the system while reducing wear on
         | the lithium-ion battery.
         | 
         | From TFA.
        
       | zeristor wrote:
       | Its like no one has heard of Stocking Pelham from 4 years ago:
       | 
       | https://stateraenergy.co.uk/Energy%20Storage%20Facility/pelh...
        
         | jacquesm wrote:
         | But that's just Lithium Ion cells.
        
       | apendleton wrote:
       | The mix of lithium ion and flow batteries here (50MWh of the
       | former vs. 5MWh of the latter) kind of makes this feel like a
       | proof of concept to me on the flow battery side -- I'd sort of
       | expect the reverse, and to want to mostly lean on the flow
       | batteries because of their suitability for long-duration storage
       | and their tolerance of lots and lots of cycles, and mostly only
       | use the lithium ion when you needed lots of power or to handle
       | rapid changes in demand. But maybe I misunderstand the dynamics
       | here?
        
         | jacquesm wrote:
         | If you think of the flow battery as a fast cache and the
         | Lithium Ion as a slower one then that might help you form a
         | better picture.
        
         | tacLog wrote:
         | I think they covered this question pretty well here:
         | 
         | > Invinity's vanadium flow batteries are used to 'front-end'
         | the energy asset, acting as a first line of response when the
         | system is called into service; only after the required response
         | exceeds the capacity of the Invinity battery does the lithium-
         | ion battery get called into service. Since Invinity's flow
         | battery does not degrade with use and can cycle indefinitely,
         | it performs much of the 'heavy-lifting' required from the
         | system while reducing wear on the lithium-ion battery.
         | 
         | What I think this means, is the the 5Mhw of flow batter covers
         | demand spikes and the 50Mhw allows for larger longer draws
         | during off peak renewable times.
         | 
         | I am just an enthusiastic auteur in this field and could be
         | very wrong.
        
           | aftbit wrote:
           | But why? I thought one of the chief advantages of flow
           | batteries was a lower cost per kWh at scale, as the expensive
           | electrodes can be sized for peak power, while the cheaper
           | electrolyte can be sized for capacity. Perhaps the economies
           | of scale in lithium-ion batteries have had a bigger impact on
           | cost than this clever split, so lion is actually cheaper per
           | kwh?
        
             | apendleton wrote:
             | Yes, exactly, this was my question as well. I understand
             | their explanation for how they're using it, but it seems
             | like the economics would be much better if configured
             | differently.
        
           | trasz wrote:
           | Kind of battery cache?
        
           | squeed wrote:
           | I think you're basically right. I know some people that
           | looked in to building a flow battery (it didn't pan out for
           | other reasons). The utility wanted it for frequency
           | regulation - in other words, extremely short timescale
           | response times.
        
       | trebligdivad wrote:
       | They don't say why it's combined with traditional lithium ion -
       | wasn't one of the promises of Flow that they can scale it up for
       | longer storage just by adding more liquid?
        
         | jacquesm wrote:
         | It's not a matter of being able to scale it up, it is mostly a
         | cost optimization.
        
         | Trombone12 wrote:
         | Guessing blindly here, but maybe the liquid is pretty expensive
         | still?
        
       | [deleted]
        
       | pphysch wrote:
       | Why is this news? It's a 5MWh vanadium flow battery. Another
       | country put online a 800MWh vanadium flow battery (160x larger)
       | this year [1].
       | 
       | > Not only will this be the largest directly-transmission-
       | connected battery installed in the UK to date, _it will be the
       | largest vanadium flow + lithium-ion hybrid battery ever
       | deployed._
       | 
       | This is like boasting you have the world first, largest ever
       | potato+nuclear reactor energy source by throwing a potato in an
       | existing nuclear reactor. Good PR for securing the next contract
       | from dimwitted bureaucrats, I guess, but hardly a genuine
       | exposition of cutting-edge technological development.
       | 
       | [1] - https://www.power-technology.com/marketdata/dalian-uet-
       | rongk...
        
         | gandalfian wrote:
         | "Why is this news? Another country put online a 800MWh vanadium
         | flow battery"
         | 
         | Did they actually finish building it and get it working and
         | achieve a reasonable cost? Or is it just a big announcement and
         | PR release so far? But yes if they do manage it that is
         | amazing. Otherwise just peacocking.
        
           | pphysch wrote:
           | Yes, the project started 5 years ago IIRC and completed this
           | year.
        
             | jacquesm wrote:
             | It was _scheduled_ to complete this year (in fact, it was
             | originally scheduled to be completed in 2019, then 2020,
             | and then it was supposed to be 2021), but it has as far as
             | I know not been completed yet and has not been taken into
             | general service. Proof to the contrary would be gladly
             | accepted, if they get it to completion and it functions as
             | advertised it will instantly be the largest of its kind in
             | the world.
        
           | jacquesm wrote:
           | From what I know about it it got delayed twice by more than a
           | year and isn't operational.
        
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