Spain 'goes 50% wind powered' - in the small hours
Wind power: Ideal if you don't need the lights on
Comment The Spanish wind power industry has proudly claimed that it has "set a new record" in that it delivered more than half the electricity used in all of Spain for several hours.
The "record" is less impressive than it sounds, however. It was achieved during the small hours of a Sunday morning, when electricity demand is lowest. The Spanish electricity grid organisation, Red Eléctrica, says that wind met more than 50 per cent of demand from 0300 to 0830 on Sunday morning, peaking at 53.7 per cent.
According  to the Asociación Empresarial Eólica (the Spanish wind-biz alliance) this indicates that "wind energy is no longer marginal". Web-2.0 media commentator "diegocgteleline.es", writing  for Slashdot, goes further and interprets the matter thus:
One of the most frequently raised arguments against renewable power sources is that they can only supply a low percentage of the total power because their unpredictability can destabilize the grid. Spain seems to have disproved this assertion. In the last three days, the wind power generation records with respect to the total demand were beaten twice ... there was no instability. These milestones were accomplished with the help of a control centre that processes meteorologic data from the whole country.
In fact, some people have argued in the past that the surges and dips in supply from wind, solar etc can be much steeper than most "thermal" powerplants - fossil and nuclear - can match, meaning that such plants can't be used to successfully back up a big fraction of wind on a national grid as they can't respond quickly enough to changes in the windfarms' output.
Thus, detractors of wind have argued, use of a large amount of wind would require the building of a substantial amount of faster-responding backup plant - probably "pumped storage" facilities, in which water is pumped uphill using electricity when prices are low, then later allowed to flow downhill through generator turbines when prices are high. (The price differences need to be substantial for the pumped-storage plant to pay its way, as a lot of 'leccy is wasted doing this.) Pumped storage plants cope well with short-term, spiky variations in wind whether they are storing or generating at the time; one can throttle the pumps up and down as rapidly as one can the turbogenerators.
As one might expect, given that Spanish wind was able to cope with a big fraction of demand - albeit the low demand of night-time - a large amount of pumped storage was in play. Hydro stations were never less than 6 per cent of total "demand" during the 0300-0830 period trumpeted by the wind biz, and sometimes more than 10.
Given enough pumped storage in operation, there won't be any catastrophic grid problems when large amounts of wind power are used. Wind needs pumped storage in order to stop being marginal - the use of fancy meteorological networking is comparatively unimportant.
Unfortunately wind also needs thermal power too. Pumped storage facilities able to power a nation for days are physically possible - though you'd probably have to start building them out at sea  once the supply of mountain valleys ran out - but not economically possible.
Actually, spiky supply is the least of the objections to wind power
Inconveniently, though, days-long midwinter calms across continental areas - certainly across western Europe - are a fact of life . If there were nothing but windfarms and realistic amounts of pumped storage, the lights would go out for days at a time on a fairly regular basis. Thus the existing thermal sector - or something just as powerful - would need to exist too, in a wind-grid future world.
The trouble with that is expense. Wind electricity is very expensive to begin with: only government market-meddling  allows turbine farms to be built. In the UK, the costs are passed on to the consumer in the form of price rises - the Treasury pays nothing. As the government drives more wind into the market by cranking up the renewables-obligation scheme, pumped storage plant will need to appear alongside it - again, with the very large costs of the construction appearing on electricity or tax bills.
After a certain amount of renewables have been forced into the system, the thermal sector will decline to where it can no longer power the country reliably on its own - some would say we have already reached this point, in fact, as it requires only two big thermal plants to go offline unexpectedly to cause power cuts  at the moment. Then, if nothing is done, the next long midwinter calm will see the lights go out - and the fridges shut off, the gas boilers' electric thermostats stop working, the trains cancelled etc etc - for days, not just hours.
In order for this not to happen, even more government action will be required in order to keep economically unviable thermal plants sitting about ready to fire up at a day or so's notice once the pumped-storage reservoirs are emptied - costing, again, a fearsome amount. In effect we will have replaced one system of powerplants - the old-time almost-all-thermal one - triplefold: thermal + wind + pumped. That would be very expensive indeed, all the more so as we are also planning to use a lot more electricity so as to replace petrol in cars, gas in homes etc.
That, in fact, is what people tend to object to about renewables - not the fact that their supply chart is so spiky, as diegocgteleline.es fondly believes, but the facts that they will be cripplingly expensive to use on a large scale in real life and will mean that the human race is always starved for energy. Affordable energy is what makes modern Westernised life so nice - it means regular washing, clean clothes, enough to eat for all, lighting, jobs outside the agriculture sector. Energy is water , information, leisure time, education. Making energy a lot more expensive makes all those things into luxuries: probably luxuries only possible for a small number of rich people, as in the sustainably-biofuelled, hydro- and wind-powered past.
Fossil fuels may well result in damaging global warming, or alternatively they may run out inconveniently soon. They absolutely definitely require the free world to truckle to nasty resource-rich governments, with associated evil effects on on foreign countries and ourselves. But none of these issues are so threatening as to justify more or less destroying modern society and remaking all of humanity as medieval (or if we're really lucky, 18th-century) eco-peasants, even if it could actually be done. Better, frankly, to have floods in fifty years and enough resources to build dykes and move populations, than spend the next twenty thousand years as hapless energy-poor primitives before being wiped out by the next ice age or spontaneous global warming* or asteroid strike. Better still, probably, to move to other kinds of thermal power  and avoid all of this.
Better by far, ultimately, for the human race to strive to become independent of its mother planet for survival - to one day interact meaningfully with the vast universe around us, rather than staring into our own navels on the surface of one tiny dust-mote until some insignificant accident erases us all. Such aspirations are probably impossible even for a comparatively energy-rich fossil-burning society - something better will be needed. They are certainly impossible for a humanity powered by windmills.
Fortunately then, the Spanish wind biz are of course wrong when they say that they are now no longer marginal. Supplying 50 per cent of demand (possibly 50 per cent - this uses estimated figures, the actual metered wind output is significantly lower ) in the middle of the night means nothing. Over time, Spanish wind actually supplies no more than 11 per cent of demand.
And in fact the Spanish government seems to have realised that renewables past a certain point are an expensive luxury indeed. The weekend's meaningless wind "record" comes against a background of Madrid cutting back sharply  on its renewables subsidies. ®
*Yes, global warming has happened in the past without any human carbon emissions.