One of the appealing things about pumped hydro storage is the responsiveness - that same source notes that as a spinning reserve, powered by the conventional hydro facility using the same upper reservoir, as able to come online in 15 seconds. And AFAIR there is a pumped hydro installation somewhere in the UK that can reverse from storage to power generation in a handful of minutes. I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
That form of storage on a grid will be especially useful when volatile energy sources in the portfolio are running below average demand, as they allow energy to be brought in over the grid to grid HVDC links in off-peak periods and stored for use during peak demands.
The Wikipedia mentions that it, too, was originally planned for use with shifting nuclear generated electricity from off-peak to on-peak, and with the switch in nuclear plans a sister plant at Exmoor was never built. I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
