Quote:
Originally Posted by nomadking
If gas powered plants are still needed overnight, then there are no savings. All it can do is reduce the daytime requirements for gas powered plants, leaving the spare capacity available for surges in demand or generation problems elsewhere. Still doesn't explain why the pumped storage generation is zero.
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Pumped storage hydro is exactly what it says it is - a store of energy. A great big battery, in effect. It uses excess base load generation overnight to run the pumps that push water uphill and releases the water back down through the generator during the day. Hydro can spin up very quickly so it is used to satisfy demand spikes especially at peak times.
The overnight electricity comes from sources that can’t easily be stopped, like nuclear, coal/biomass and, to a limited extent, gas, though a gas plant can actually be started and stopped quite quickly at the cost of reduced efficiency. As we can’t control when the wind blows I believe a fair amount of wind power may also end up being used to run the pumps, if the wind is blowing.
There are various reasons why pumped storage may presently be showing zero generation. It might be that in summer the load spikes aren’t there. It might also be that a balance must be maintained with the amount of water flowing naturally in the highlands where most of these systems are. There is reduced rainfall in Scotland this summer, albeit not as bad as in England.