UK Nuclear Fleet

[Mart]

I always find "RE excess with curtailment" an interesting one.
At the moment curtailment is only taking place to balance the grid and often brought on by transmission bottlenecks. This will continually be improved.

But with time of use tariffs and demand shifting will there ever be much curtailment of excess production. When all cars are EV the capacity to soak up this "excess" will be huge. Peak curtaiment nearly always aligns with ev charging at night.

Also as soon as one mentions FREE do you not think someone is going to come up with a way of using this,like small intermittent production or increasing the size of the upper reservoir on pumped hydro.

Hiya Ken, I also find it incredibly interesting. Can't pretend that I can get my head around it, but in general I think the long term argument is that some curtailment (no idea what percentage, but let's just say 0-5% for now), will be cheaper, than adding more storage to mop that bit up.

At least that's the theory. It certainly nakes sense to me in countries with better PV generation, and daily predictability. In the US where 1.5x our gen is 'easy', or 2x with single axis trackers, then you have PV generation costs down around $20/MWh already in some cases, and costs keep falling. So, and again, entirely theorising, I know no more than you, but if the running costs of storage are more than $20/MWh, then you'll reach a tipping point where overcapacity will be more economic than storage.

But, like you, I don't forsee any major issues with storage, be it short intraday, or long term, as the cheap excess of leccy, at times, will bring out the clever people who can see a way to make a profit. Perhpas we will see a saw tooth graph of excess, where it grows to a certain point, before it's viable for some additional, or new storage, and drops again, before repeating that pattern?

Edit - BTW, again, may be talking carp, but I suspect the UK will be different to the average, as our offshore wind potential is so, so huge, so we may need storage for troughs, but perhpas not for the whole of the peaks. For now, I expect it will displace FF genertaion in Europe, but could start to displace some hydro gen too (for use later on), if the UK excess is so cheap, that it undercuts other generation. Again, this is purely theory (mine), not a statement of what will happen, as the RE revolution is mind blowing, and the BEVolution, at the same time, will create demand and storage issues, so there will many cross issues developing, where the whole will be greater than the sum of the parts. M.

[nowty]

Some quite interesting info here on battery vs transmission upgrades to alleviate constraints on wind generation.
https://timera-energy.com/battery-value ... anagement/

[Stig]

I can see the case where curtailment is cheaper than adding storage. That's the case on a small scale, i.e. for me, where solar power isn't used locally during the summer (exported) but the cost of adding storage outweighs the cost of importing power overnight.

Back of envelope calculations:
import 30kWhr a month during summer @£0.30/kWhr = maybe £30 - £50 a year
cost of 1 - 2kWhr storage and inverter = £hundreds
-> payback period = 10 - 30 years

[Swwils]

Small amounts of curtailment is healthy short term but large amounts is silly and eventually you would want no curtailment at all as you wouldn't be able to achieve a zero carbon grid otherwise. Germany and now UK facing huge issues load following wind outputs.

You have to be very wary of flying the "storage" flag, grid scale chemical storage is not a technology that is anywhere near advanced enough on the readiness scale.

Overbuilding of RE sounds good in principle until you do an in-depth analysis, true costs can be staggering at many places in the chain. You wouldn't for instance be able to have any turbines at all without significant amounts of diesel fuel, concrete, acid production etc.

[AE-NMidlands]

I can see the case where curtailment is cheaper than adding storage. That's the case on a small scale, i.e. for me, where solar power isn't used locally during the summer (exported) but the cost of adding storage outweighs the cost of importing power overnight

I don't get this. If we acknowledge that there will inevitably be cold cloudy calm periods (of days or even weeks) when pv and wind won't generate, then surely we want something up our sleeves to avoid having to burn stuff just to keep the grid working? Which means storage of some or several sorts. We can't just rely on places at the other end of interconnectors to bail us out in these circumstances (even if there was enough capacity.)

I would be all for building loads of storage facilities (of various sorts) and then drawing from each storage facility in turn on a regular basis so that they get some income all the time and can be sure that their kit works without having to generate just to dump it.

[Stig]

I can see the case where curtailment is cheaper than adding storage. That's the case on a small scale, i.e. for me, where solar power isn't used locally during the summer (exported) but the cost of adding storage outweighs the cost of importing power overnight

I don't get this. If we acknowledge that there will inevitably be cold cloudy calm periods (of days or even weeks) when pv and wind won't generate, then surely we want something up our sleeves to avoid having to burn stuff just to keep the grid working? Which means storage of some or several sorts. We can't just rely on places at the other end of interconnectors to bail us out in these circumstances (even if there was enough capacity.)

I would be all for building loads of storage facilities (of various sorts) and then drawing from each storage facility in turn on a regular basis so that they get some income all the time and can be sure that their kit works without having to generate just to dump it.

Absolutely agree, storage is better than burning stuff. My point was that it's often more expensive than burning stuff.

[Mart]

The storage v's curtailment issue really isn't that complicated. It pretty much comes under the 'don't let the perfect be the enemy of the good'.

Storage has a cost, generation has a cost. If the cost and benefits of storage is less than the benefits of additional RE, after accepting greater curtailment, then that's the option.

Nothing wrong with subsidising storage, or alternating which one is used, say 1 out 3 taking turns, but that's still a cost, after all the 3 storage facilities are now seeing 1/3rd of the cycles, v's one facility. If the cost of that is less than additional RE (with curtailment), then that's great, if not, then the timing is still wrong.

Household PV'ers won't buy a battery for one day a year when they have excess, nor for say 100Wh of excess each day. Batts will be added when there's enough ecomoic excess, which will mean both volume and frequency. As that excess develops, so will an appropriate (economic) amount of storage.

And in these examples, 'economic' isn't a negative, where we hold on to monies/subsidies, it's about balance, v's spending the monies on more RE generation. It's purely a balancing act that will develop and deploy naturally.

That said, at the moment we are in a different phase of storage, as regardless of storage or curtailment, we will still be consuming a significant level of FF generation. Hence why more RE and interconnectors are the key at this stage, especially given that storage is still in its early days, with costs (and benefits) to improve. Again we can look to demand side PV for an example - one property with excess can help to decarbonize neighbours, but as more and more properties add PV, then there may be a problem (or a very low value) with that export, so storage becomes more economic.


With all the high penetration RE studies and reports that suggest economic curtailment, they are not claiming that curtailment itself is a good thing, but simply pointing out that the cheapest and fastest way to displace FF's, will always include an economic level of curtailment.

[Mart]

This news piece from yesterday may be of interest. It shows how storage is being deployed, or projects/plans without storage are now being considered for co-location with storage. And follows in the claims of both the PV and on-shore wind industry bodies, who've always claimed that storage will be added to new schemes, or retrospectively to older ones, once viable.

UK ROUNDUP: FRV, TagEnergy finance 366MWh, SSE acquires solar sites with co-location potential

[Joeboy]

This news piece from yesterday may be of interest. It shows how storage is being deployed, or projects/plans without storage are now being considered for co-location with storage. And follows in the claims of both the PV and on-shore wind industry bodies, who've always claimed that storage will be added to new schemes, or retrospectively to older ones, once viable.

UK ROUNDUP: FRV, TagEnergy finance 366MWh, SSE acquires solar sites with co-location potential

A good quick read, a few years back we were bemoaning the lack of speed in the uptake of grid battery storage and here it is now, nice.

[Mart]

This news piece from yesterday may be of interest. It shows how storage is being deployed, or projects/plans without storage are now being considered for co-location with storage. And follows in the claims of both the PV and on-shore wind industry bodies, who've always claimed that storage will be added to new schemes, or retrospectively to older ones, once viable.

UK ROUNDUP: FRV, TagEnergy finance 366MWh, SSE acquires solar sites with co-location potential

A good quick read, a few years back we were bemoaning the lack of speed in the uptake of grid battery storage and here it is now, nice.

Yep, I think we may have reached a tipping point. I don't pretend to understand the full details, nor economics, but in general I think the process is roughly, that you need to add RE, then you need some excess, then you need a large enough amount of excess, then on a regular enough basis, and finally cost effective storage. Once that happens, you roll out storage and rinse and repeat.

As RE gets cheaper, it helps with the scale and regularity of excess, and falling storage costs 'attack' the problem from the other direction.

But for now, interconnectors will mess this process up a bit, but all in a good way, eventually.

Incredible how interesting batteries have become, funny ole world.