UK Wind Power "Debate" : Latest | 71 comments (71 topical, editorial, 0 hidden)

Just musing about storage (none / 0)

About those countries, notably Scandiwegians, which have considerable hydro capacity :

Can they retro-fit to provide pumped storage?

i.e. when wind would otherwise be spilled, dammed hydro is not running. Can it be "run backwards" to soak up the wind? Is this not a cheaper option than new pumped storage facilities?

_{It is rightly acknowledged that people of faith have no monopoly of virtue
- Queen Elizabeth II}

by eurogreen on Wed Oct 24th, 2012 at 08:11:21 AM EST

Re: Just musing about storage (none / 0)

Interesting question.
Wikipedia suggests 70% efficiency. Not bad.

by Number 6 on Wed Oct 24th, 2012 at 08:24:03 AM EST
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Re: Just musing about storage (none / 1)

Oooh, cool option: a giant underwater balloon!

by Number 6 on Wed Oct 24th, 2012 at 08:25:28 AM EST
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Re: Just musing about storage (4.00 / 5)

In many cases they could. But the economics aren't that great. The storage hydro already provides pseudeo-pumped storage, becase they're seasonal, and they meet primary domestic demand.

So, whenever, say, Denmark's got a surplus of energy (and that's almost always because they're running their thermal plant so high; it's only due to too much wind for a few dozen hours per year), they can export to Norway/Sweden, who then turn down the output from storage hydro a bit, and use Danish power instead.

So, let's say Norwegian demand is running at 15GW, and that's supplied by 15GW of hydro - some run-of-river, some storage hydro. If Denmark's exporting 1GW, they can just turn down the storage hydro by 1GW. That way, their storage hydro acts as a pseudo pumped-storage anyway, because it's time-shifting its output.

So, they'd only need to consider building actual pumping facilities, once their total power imports exceed domestic demand. They're not there yet. But if a dozen countries each fancied a few GW of interconnector with Norway, such that net imports to Norway might exceed domestic demand frequently, then the business case might start stacking up for retrofitting pumping facilities.

by LondonAnalytics (Andrew Smith) on Wed Oct 24th, 2012 at 12:03:34 PM EST
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Re: Just musing about storage (none / 1)

So 'reduce' before 'reuse'?

by Number 6 on Wed Oct 24th, 2012 at 12:06:57 PM EST
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So in theory (none / 0)

if the UK looked like routinely producing multiple-gigawatt power surpluses on windy days, then you would need to justify the cost of the interconnect and of the pumps. It could run the other way, of course, on cold windless days.

That cost might be a bit high if it's only a matter of extreme peaks and troughs, a few hundred hours a year? But if the Scandi hydro pumped storage benefited all Europe, that would mutualise the costs.

Would UK excess wind be characterised by season? Mostly in winter? In that case it wouldn't seem to be a good fit for longer-term smoothing: dams already full I suppose.

_{It is rightly acknowledged that people of faith have no monopoly of virtue
- Queen Elizabeth II}

by eurogreen on Thu Oct 25th, 2012 at 05:50:45 AM EST
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Re: So in theory (4.00 / 4)

Can I just point out that the Imperial College paper summarized above makes a good case for saying that over- and under-production (from wind) are not major problems, for the years to 2020 and looking immediately beyond?

The discussion (of what to do with excess wind output) seems posited on a vague future state first (I think) evoked in this thread by Thomas.

Not that the uses excess output could be put to is not a valid debate.

by afew (afew(a in a circle)eurotrib_dot_com) on Thu Oct 25th, 2012 at 06:13:59 AM EST
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Re: So in theory (none / 0)

if the Scandi hydro pumped storage benefited all Europe

As LondonAnalytics pointed out, it mostly isn't at present and doesn't have to be pumped storage.

That cost might be a bit high if it's only a matter of extreme peaks and troughs, a few hundred hours a year?

I think using interconnections for smoothing can be cost-effective in times of less extreme wind peaks and throughs, too: that would still mean less use of gas. This depends of course on how much of a phase shift there is between wind peaks and throughs passing the western shore of Ireland and the Netherlands (at least).

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Thu Oct 25th, 2012 at 07:25:11 AM EST
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Re: So in theory (none / 1)

Mostly in winter? In that case it wouldn't seem to be a good fit for longer-term smoothing: dams already full I suppose.

See page 29:

http://webby.nve.no/publikasjoner/rapport/2012/rapport2012_19.pdf

Actually winter/spring seems OK for sending electricity over there.

by mustakissa on Thu Oct 25th, 2012 at 10:45:47 AM EST
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Re: So in theory (none / 0)

Actually, looking at the amount of water (which they conveniently measure in gWH per week!) which the dams absorb in May and June (graph page 28), I guess that means that they can be used for soaking up any amount of excess wind -- through production and/or reverse pumping -- for ten months of the year!

And as the graph on page 29 shows, they never get more than 90% full...

A gold mine.

_{It is rightly acknowledged that people of faith have no monopoly of virtue
- Queen Elizabeth II}

by eurogreen on Fri Oct 26th, 2012 at 04:10:00 AM EST
[ Parent ]

Re: So in theory (none / 0)

It should be noted that under the current system for organizing international electricity trade, a gold mine is exactly what this is - Denmark does exactly what is proposed here already, and while the net trade in kwh sums to near zero, the net trade in kroner favors the storage vendors. A lot.

.. Which actually causes me a good deal of puzzlement. Selling timeshifting is currently a heck of a lot more profitable than selling intermittent electricity is, yet investment in intermittent generation capacity appears to be running ahead of investment in grid and storage quite badly.

by Thomas on Fri Oct 26th, 2012 at 04:31:15 AM EST
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Re: So in theory (none / 1)

It should be noted that under the current system for organizing international electricity trade, a gold mine is exactly what this is - Denmark does exactly what is proposed here already, and while the net trade in kwh sums to near zero, the net trade in kroner favors the storage vendors. A lot.

It should. They're taking lower-quality electricity and selling higher-quality electricity.

Selling timeshifting is currently a heck of a lot more profitable than selling intermittent electricity is,

That's not obvious from your example: Since there's no net trade in MWh in that example, you can't get a relative price from it.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Fri Oct 26th, 2012 at 05:26:01 AM EST
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Re: So in theory (none / 0)

You can, if you buy at a lower price and sell at a higher price. But indeed I'd like figures on that.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Fri Oct 26th, 2012 at 03:08:35 PM EST
[ Parent ]

Re: So in theory (none / 1)

Thomas wrote:

the net trade in kroner favors the storage vendors. A lot.

And there's typically a profit-sharing arrangement in place between both nations

investment in intermittent generation capacity appears to be running ahead of investment in grid and storage quite badly

Errrm, no. Investment in grid storage was there decades before the investment in wind and solar.

by LondonAnalytics (Andrew Smith) on Sat Oct 27th, 2012 at 01:42:40 AM EST
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Re: So in theory (4.00 / 2)

eurogreen:

And as the graph on page 29 shows, they never get more than 90% full...

That might be a safety feature. Since inflow from rain is not safely predictable on a longer time frame then about a week it might be prudent to keep some space clear for controlling downstreams conditions. Spilling water at times of massive rain is simple enough for the dam operator but has more externalities then spilling wind.

Sweden's finest (and perhaps only) collaborative, leftist e-newspaper Synapze.se

by A swedish kind of death on Fri Oct 26th, 2012 at 10:02:09 AM EST
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Re: Just musing about storage (none / 1)

Here I read that the Norwegians could find an extra 20 GW generating capacity, without spoiling their nature too much. Sweden would be less than that. About storage capacity (TWh), I understand that it would be "plenty" :-)

http://www.cedren.no/Portals/Cedren/Pdf/HydroBalance/1_HarbyA_Balancing%20power%20from%20Norwegian%2 0hydro.pdf

This is a slide show. There was a real report by CEDREN somewhere but I cannot find it now.

by mustakissa on Thu Oct 25th, 2012 at 10:33:46 AM EST
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Cedren Hydrobalance project reports (none / 1)

Was it one of these Cedren Hydrobalance project reports?

by LondonAnalytics (Andrew Smith) on Sat Oct 27th, 2012 at 02:26:28 AM EST
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Re: Cedren Hydrobalance project reports (none / 0)

Yep, this looks familiar. This one:

http://www.cedren.no/LinkClick.aspx?fileticket=3awZ0x991Gg%3d&tabid=4552&portalid=48&mid =5869

by mustakissa on Mon Oct 29th, 2012 at 07:08:50 AM EST
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UK Wind Power "Debate" : Latest | 71 comments (71 topical, 0 editorial, 0 hidden)