Having said that, I think it would be totally wrong to completely ignore renewables, given that they currently have the potential to service much of our current demand, particularly during hours of daylight, and are continuing to increase. Whilst there will obviously be occasional periods like you mention (over 8 years ago), when there is little wind and short days, things will more-often-than-not 'work out' reasonably well.
Indeed, and the renewables people made a big thing of the day when there was zero coal output for teh first time a couple of years ago. Yeah great - when you've got low demand, and good conditions for renewables ("the right sort of wind" and sunny), then things like coal will get shut down. And that is part of the problem - as I've mentioned before. When that coal (or gas, or ...) station is shut down, it's earning nothing yet many of the operating costs are still there. Not only that, but there's a significant cost is shutting down and starting up again (not least the thermal cycling of plant). So reduced income + static costs + additional costs = plant only economic with availability payments.
There was a period a few years ago when the BMReports site showed a forecast margin (excess of supply capacity over demand) that went negative - by a very significant amount. IIRC it coincided with announcements of some large coal plants shutting down for good. Those deficits disappeared after a while - I think when the plant operators were persuaded (with availability payments) to keep the plants available.
But "more-often-than-not 'work out' reasonably well" is not good enough unless we are happy to change to "non reliable" supplies as standard. IMO this is primarily what "smart" meters are about - getting the foundations for that in place. When "green tariffs" are interruptible supplies by default, AND people subscribe to them in significant numers - then I'll believe in the hype
We could, of course, never rely on only 'renewables', but they are coming to be an increasingly important contributor. Given the inevitable eventual exhaustion of fossil fuels, an ultimate future based on 'renewables' plus nuclear (ideally fission) would seem pretty inevitable (albeit beyond any of our lifespans).
Those two between them would not be sufficient. While nuclear is not inherently inflexible, the designs currently being built or thought about really do not suit variable output - especially trying to follow not just demand changes but also make up for variations in supply from renewables. Things like pumped storage help - but we have limited capacity and I think trying to significantly increase that would meet "considerable resistance" - I can imagine the reaction if you (for example) wanted to dam up Windermere (it's got a huge surface area so ideal as a PS lake) at Newby Bridge and raise it's level by (say) 10m
And realistically, that's about it as far as large scale storage goes.
As little as that. It's normal for a lot of plant to be unavailable during summer - there's enough margin to allow such shutdowns in a planned manner for routine maintenance. I recall looking at the graphs in the old BMReports and there was generally a distinct dip in forecast supply capacity during summer.
I get the impression grid connected storage is the future for electricity networks -it solves the issue of solar and wind renewables.
Yes indeed, in much the same way that transporter technology (c.f. Star Trek) solves transport problems
12GW is a meaningless figure. Rack up a few supercaps and you can probably generate multi-megawatt powers in your living room - for a few microseconds.
For example, just down the road from me, there's a
49MW battery that apparently went live just before Christmas. Yup, that's a large shed full of laptop batteries (no, not literally, but same chemistry) and electronics. And it can provide (if used in that way) just 24.5MWh. Note that it's part of a project refurbishing a CCGT and some fast reacting (I assume OCGT) units.
I have seen a figure for how much this plant cost, but at the moment all I can find is it being part of a bigger £180M project. I doubt that it works out at less than £1M/MW of rating or £2M/MWh of storage capacity - probably much more.
Now, a few years ago I recall reading an article in one of the IET journals where someone had analysed historical wind patterns (looking at wind turbine output records). There are indeed periods (albeit short) where there is no significant wind across huge areas - that's all the way from Scandinavia down to Spain. So the myth that "there's always wind somewhere" is just that - a myth. Just building bigger interconnects won't solve that problem.
In addition, I've read another article from further back, in an IEE journal, showing how one year we had a static high pressure system over the whole of southern Scandinavia and western Europe. More or less no wind across most of the continent for about 10 days. So what does that do for the storage requirements ?
Lets say we've become very reliant on renewables, we've imagined a significant amount of storage into existence which gets us along on a day to day basis - and as a result have failed to built any significant new nuclear capacity, and let a lot of old plant be scrapped. Lets say in a winter period like that 10 day one mentioned (and I suspect Dec 2010 was similar) we are (say) just 10GW short - not inconceivable. 10GW for one day is 240GWh - that's ten thousand of the above mentioned battery units. Over 10 days, it's one hundred thousand of them needed.
In practical terms, we probably wouldn't have the lithium to even make the batteries. That's ignoring the costs etc.
OK, we probably wouldn't have an average deficit of 10GW. But it does slightly show up the shear scale of storage required - hence my comment about having "imagined into existence" such a level of capacity. That is what many in the renewables lobby rely on, handwaving away intermittency problems with "will be solved by storage" - without actually coming up with actually viable and economic options for creating it.
