Spain is a leader in Hydro. Why they don’t use their dams for storage ?

Because you'd have to have engineered the whole thing for that purpose right from the get go. In theory you can run the generators in reverse and push water up the hill into the basin. In practice this may not work for a multitude of reasons (priming, encasement, rotation reversal, cavitation, impeller and impeller housing design).

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elmolino89 2 days ago | parent [-]

Also missing in vast majority of the dams is a lower reservoir. Pumping up the water from a river/canal below the dam would result in a dry river bed just below the dam rather quickly

*edit* spell

	▲	jacquesm 2 days ago \| parent [-]
		Yes, excellent point. Cruachan dam is a nice example of such a double storage setup. https://www.visitcruachan.co.uk/

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elmolino89 2 days ago | parent | prev | next [-]

Spain does have few (probably 4 according to ESP Wikipedia) pumped-storage hydroelectricity plants. Supposedly these are being used nowadays to store excess of energy produced by fotovoltaic plants. No idea how fast these can switch from storing energy to producing it and if these were used to help during the blackout.

	▲	gwbas1c 2 days ago \| parent [-]
		> No idea how fast these can switch from storing energy to producing it and if these were used to help during the blackout. Typically ~10 seconds. The bigger issue is if these have blackstart capability. (IE, if they can switch to generation when there is a blackout, or if they need power from the grid to start.)

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KaiserPro 2 days ago | parent | prev | next [-]

Reconfiguring dams for storage isn't easy, quick or possible.

Non-storage dams don't have lower lakes to pull from, and the surrounding area might not be able to support it.

plus they also need water when there are droughts, which spain is also prone to.

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marcoalopez a day ago | parent | prev [-]

they do it all the time