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}