Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
Demand varies by a factor of 3 between the lowest point and the maximum. So when you say 30%, it's 30% of what? GW, GWh, average GW, max. GW, something else?

Wind power
by Jerome a Paris (etg@eurotrib.com) on Mon Oct 22nd, 2012 at 09:26:50 AM EST
[ Parent ]
GWH. It being the only measure that means a damn.

Diurnal variation is an additional problem any clean grid has to address somehow. I am optimistic about the potential to shove consumption around within the day-night cycle - particularly if the shift is consistent.

That is, I do not think either a "All our electricity comes from desertec" or "All our electricity comes from  reactors that do not have throttles at all"  grid would face insurmountable problems. Ask people to charge at a given hour every day and that is not going to be a difficult habit to follow  
 But asking people to not go to work today because it has been a quiet week? That is not going to fly. So large variations in daily supply either require storage that can hold weeks of electricity, or the grid has to get bigger until the variations go the frack away.

by Thomas on Mon Oct 22nd, 2012 at 12:07:20 PM EST
[ Parent ]
I am optimistic about the potential to shove consumption around within the day-night cycle - particularly if the shift is consistent.

So am I. Chargeable hybrid cars can do most of that.

About the longer term (synoptic) variations, what's left of those after the European supergrid, can be taken care of by gas turbines, but burning electrolytically produced hydrogen from excess wind. Yes, an inefficient solution, but if we're talking about 10% of production we can live with that.

I see you didn't mention the annual cycle: it's a biggie, and nuclear isn't very good at following it. Wind -- or rather, a suitable mix of wind and solar -- is much better. And I'll say again what I said before: most of our energy use that produces CO2, like 3/4, does not involve electricity. Like space heating, where there is a huge savings potential through better building, heat pumps etc. Also, process industry and metallurgy. Bringing down these uses will involve electrification, which will raise electricity consumption, something I do not see in most plans. Something to be aware of.

by mustakissa on Tue Oct 23rd, 2012 at 03:07:37 AM EST
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Annual cycle: do you mean more work/energy use in 'winter'? More solar available in 'summer'? Or something else completely?
by Number 6 on Wed Oct 24th, 2012 at 09:52:15 AM EST
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That's an awfully long supply line. You better hope none of the countries providing transport have energy shortages (think : Ukraine)

It is rightly acknowledged that people of faith have no monopoly of virtue - Queen Elizabeth II
by eurogreen on Tue Oct 23rd, 2012 at 04:05:05 AM EST
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It isn't really that long, in HVDC terms... but anyway, I don't expect it will be needed. Before long the Sahara will come to us.
by mustakissa on Tue Oct 23rd, 2012 at 05:04:05 AM EST
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Or have a problem with local read-the-Koran-too-much rebels. Not that this happens quite regularly in the region.

Now I understand why the Saudians are happy about funding AQMI, obvious self interest against solar...

Un roi sans divertissement est un homme plein de misères

by linca (antonin POINT lucas AROBASE gmail.com) on Sun Oct 28th, 2012 at 12:14:26 PM EST
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Yes. Real time cost, or cost published in advance: charge at this time of night at this cost.

('Real time' feels like it would lead to Enron-style scenarios, so perhaps monthly or so updates would be better.)

by Number 6 on Wed Oct 24th, 2012 at 09:50:33 AM EST
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