Idrostoccaggio

Europe's largest pumped-storage plant; twelve sets split between a surface and an underground powerhouse on the Eau d'Olle

Europe's fastest-responding big store, inside Elidir mountain between Marchlyn Mawr and Llyn Peris

La Muela I (1989) and II (2013) share a plateau basin 500 m above the Cortes reservoir - Europe's largest pumping complex on one site

SSE's Great Glen scheme above Loch Lochy - the UK's first new large PSH in 40 years; FID hinges on the 2026 cap-and-floor award

SEO's eleven-set plant on the Our; the 200 MW eleventh machine arrived in 2015

Four of seven planned 324 MW sets run; the 2,268 MW build-out, due around 2028, would make it Europe's largest

Italy's largest hydro plant: the Chiotas (1,064 MW) and Rovina sections share the Piastra lower reservoir on the Gesso

Engie's three-basin plant above the Amblève a Coo, uprated past 1.1 GW in the 2020s

Germany's largest PSH and Europe's first big plant with variable-speed sets, on the Thuringian Schwarza

Six 175 MW sets in the Erzgebirge above the Große Mittweida; Germany's second-largest store

Four 250 MW sets between the Cesima hill basin and the Volturno plain north of Naples

Pumps from Lake Maggiore 740 m up to Lago Delio; the hall in the cliff holds eight sets

Studied since the 1980s above the Tarnița reservoir near Cluj; still lacks financing and a start date

Axpo's cavern plant lifts Limmernsee water 630 m to the dammed Muttsee, 2,474 m up - Europe's highest big reservoir

Soviet-era project on the Kaniv reservoir repeatedly restarted by Ukrhydroenergo; construction remains suspended

Eight sets on the Oglio a Edolo fed from Lago d'Avio; commonly rounded to a gigawatt

Four 227 MW sets underground on the Truyère; EDF's second-largest storage plant

The Hornberg basin sits 600 m above the Wehra valley - the biggest machine in the Black Forest group

Four 225 MW sets against the Kaunas reservoir on the Nemunas, built to firm the Baltic grid, with room for a fifth unit

Six variable-speed sets between the Emosson and Vieux Emosson lakes above the Rhône's Trient gorge; 20 GWh of storage

Pure pumping plant of Iberdrola's Tâmega 'giga-battery', working against the Daivões reservoir

The Balkans' largest PSH, below the Belmeken reservoir; offline after a March 2022 turbine failure, with unit 2 back a 210 MW in May 2025 and two more sets due through 2026

Six sets 400 m underground pump the vast Almendra reservoir on the Tormes against the Duero canyon

Upper basin on the plateau above the Meuse loop a Revin - lowland France's counterpart to the Alpine stores

Bissorte's reversible extension in the Maurienne, working the 1930s Bissorte dam against the Arc valley floor

Two 368 MW variable-speed sets - among Europe's largest such machines - on the same Rabagão-Cávado drop as Frades I

The largest power station in Slovakia of any kind; upper basin dug into the ridge above the Čierny Váh valley

Europe's highest-head pumped storage; the Rottau powerhouse in the Möll valley works 1,106 m below the Kölnbrein reservoir

Poland's largest PSH, on glacial Lake Żarnowiec - built to partner a nuclear plant that was never finished

Terna's twin upper basins (Agios Georgios 460 MW, Pyrgos 220 MW) share the Kastraki reservoir on the Acheloos; first units due 2027

Largest hydro plant in Czechia; twin 325 MW Francis sets under Mravenečník, with the upper basin dug into the Dlouhé stráně summit

Norway's largest pumped-storage plant; two of its four sets are reversible, cycling Blåsjø water in the Ulla-Førre scheme

Two 307 MW sets pump 600 m up from the Perućac reservoir on the Drina to Lake Zaovine on Tara mountain

Italy's highest head - 1,404 m from Lago d'Arno down to the Oglio a Sellero

Two twin-set reversible stations (2004 and 2012) on Iberia's largest reservoir, pumping against the Pedrógão pool of the Guadiana

Sicily's big storage plant, in caverns beside the Anapo gorge above Syracuse

Upper basin carved into the summit of Mt Żar, lower pool on the Soła cascade

Mixed pumped stage between the Campotosto and Provvidenza reservoirs under the Gran Sasso

Reversible cavern sets between the Mooserboden and Wasserfallboden reservoirs above Kaprun

Opened September 2025 on the same reservoir pair as Limberg II; both motor-generators failed within weeks, with repaired sets due back in September and December 2026

Four reversible sets between the Dalešice and Mohelno reservoirs; the same Jihlava pool cools the Dukovany nuclear plant

Two 240 MW reversible sets between the Flumet basin and the Isère's Grésivaudan valley

Two 240 MW cavern sets beside Waldeck I, pumping from the Eder's Affoldern pool

Pumps Lake Geneva water 880 m up to Lac de l'Hongrin; the 2016 Veytaux-2 cavern doubled it to 480 MW

Pure pumping plant in a cavern between the Sallente and Gento lakes of the Catalan Pyrenees

Three Pelton sets with separate pumps (525 MW pumping) between the Kops reservoir and the Rifa basin a Partenen

Underground plant near the Neretva delta; the karstic Trebišnjica, half canal by now, is its upper pool

The original 'Hollow Mountain' under Ben Cruachan, pumping from Loch Awe; Drax shelved its 600 MW expansion in 2025

Links the Reißeck and Malta groups, cycling water between the Mühldorfer See and Gößkar reservoirs

Two reversible sets inside the Duero canyon plant; the full Aldeadávila complex reaches 1,243 MW

France's first high-head pumped storage, above the Isère a Aigueblanche; an extra Pelton unit joined the four reversible sets in 2019

Greece's largest hydro plant, a reversible station on the Nestos gorge near the Bulgarian border

Post-war cavern plant in Trentino that can pump back up to Lake Molveno

Spain's south-coast store above the El Chorro gorge of the Guadalhorce

Top stage of the Belmeken-Sestrimo-Chaira cascade in the Rila mountains; two of its five sets are reversible

Second Zillertal stage; pumps from the Ziller headwaters back up to the 186 m Zillergründl arch dam

Cavern plant between the Silvretta and Vermunt reservoirs a the Ill's source; 360 MW in both turbine and pump mode

Cavern plant under the Eggberg with its basin on the Hotzenwald shoulder, tailing into the High Rhine

Pumps from the Alsa reservoir in Cantabria's Besaya basin; Repsol has an expansion to ~1 GW on the books

Britain's first major pumped storage, between Llyn Stwlan and the Tan-y-Grisiau reservoir

KWO's cavern plant between the Oberaarsee and Grimselsee a the Aare headwaters; four ~87 MW sets, one converter-fed

Three reversible groups on the Mondego above Coimbra

Two sets on the Suviana reservoir in the Apennines; offline since a fatal April 2024 machine-hall explosion, with repairs still running

Eight small sets on the Saale cascade's Hohenwarte reservoir - the GDR's flagship store

Three reversible sets on the middle Aliakmonas, regulating PPC's cascade below Mount Vermio

Mixed plant of the Sil system with pumping capability, downstream of the Conso group

Two of six planned 151 MW sets run beside the South Ukraine nuclear plant; unit 3 has crept forward for years

Two-stage Tamina scheme with pumping between the Gigerwald reservoir and the Mapragg basin

Pumps from Loch Ness up the fault scarp to Loch Mhòr, reusing the site of the 1896 aluminium-works hydro

Core of the San Agustín-Conso group in the Bibei headwaters of Galicia's Sil sistema

Single large reversible set beside Rodund I; rebuilt after a 2009 machine fire

Ireland's only pumped storage, between an artificial summit basin and the glacial Lough Nahanagan in the Wicklow mountains

Pumping stage of TIWAG's Sellrain-Silz group, cycling the Finstertal and Längental reservoirs above the Inn

Pumps from the Zrmanja up to the Opsenica basin on the Velebit karst plateau

Reversible stage of the Aurland mountain cascade above the Sognefjord

Dam on the lower Tua whose reversible sets pump against the Douro backwater

Three reversible sets a the Valdecañas dam on the middle Tajo

Sardinia's pumped storage, between the Cucchinadorza and Benzone reservoirs on the Taloro

The USSR's first big pumped storage (1970-72), on the shore of the Kyiv reservoir

Zemm valley plant pumping against the Schlegeis reservoir in the Zillertal group

Five sets between the Lünersee and the Latschau basin; illwerke's planned Lünerseewerk II would add 1,000 MW on the same lake

Lower Saxony's only large PSH, with its basin on the Selter ridge above the Leine

Middle stage of the Schluchsee cascade, on the Schlücht between the Häusern and Waldshut steps

Mixed plant of the Piave-Santa Croce cascade, pumping between Lago Morto and Lago di Santa Croce

Companion pumping plant to Conso in the Bibei headwaters

Three reversible sets north of Seville - Andalusia's counterweight to the Pyrenean stores

Single large reversible set in a cavern beside the 1953 Salamonde dam on the Cávado

Two reversible sets a the top of the Sira-Kvina system, between the Svartevatn and Gravatn reservoirs

Two of the four sets a Poland's tallest dam are reversible against the Myczkowce pool of the San; modernised 2003

Four reversible sets lift Tagus water 240 m to La Bujeda, the head pond of the Tagus-Segura transfer

Pumps from the Baserca reservoir up to Llauset, under the Pyrenean main ridge

Workhorse of the Obere Ill-Lünersee group, between the Latschau basin and the Ill a Vandans

Mixed plant on the Váh: two Kaplan sets work natural inflow, two reversible Dériaz sets pump from the Bešeňová pool

First reversible extension of the Venda Nova scheme, from the Rabagão reservoir down to Salamonde

Two 95 MW pump-turbines and a new Kühtai reservoir; test operation began August 2026, regular service planned late 2027

Two-step reversible scheme on the Sabor, the Douro's last wild tributary before it was dammed

Slovenia's only pumped storage, a variable-speed set above the Soča a Avče

Kraftwerke Hinterrhein's pumping stage between the Valle di Lei reservoir and the Sufers pool on the Hinterrhein

Energie AG shaft plant pumping out of the Traunsee; completion planned for 2027

ÖBB's 16.7 Hz railway plant between the Weißsee and Tauernmoossee in the Stubach valley; misfabricated turbine spirals pushed commissioning to summer 2028

Ofima's pumping hub in the Maggia system, cycling water between the Robiei and San Carlo basins in Val Bavona

The 1950s Kaprun Oberstufe between Mooserboden and Wasserfallboden; its generators are under repair through 2026 alongside Limberg III's

Offline since 2011 when the upper basin floor failed; Uniper is rebuilding it for a return around 2028

Runs on the 16.7 Hz railway grid for DB Energie, above the Sinn in the Spessart

Early lake-to-lake plant between Kamienne and Kwiecko lakes in Pomerania

Replaced Arthur Koepchen's landmark 1930 machine hall on the Hengstey lake of the Ruhr

Bottom stage of the Schluchsee cascade, pumping straight out of the High Rhine

High-head Susa valley scheme with pumping between Val Clarea basins on the Dora Riparia

Reversible plant a the Tâmega mouth, pumping from the Douro's Crestuma pool

Sits on Belgium's largest artificial lakes, built to compensate Sambre water taken for cooling

Kelag's two-set plant in the Fragant group of the Möll basin, between the Feldsee and the Wurten reservoir

Twin basins above the Lenne valley a Finnentrop, on the little Glinge stream

The 1930s pioneer above the Edersee, gutted and rebuilt with modern sets in 2010

Pumps between Lake Valvestino and Lake Garda from a shoreline hall on the west bank

Mixed plant pumping between the twin Torrejón pools on the Tajo and the Tiétar

Draws down the Homem valley reservoir - famous for the drowned village it covers - and pumps back from Salamonde

Reversible sets between the Tanes and Rioseco reservoirs on the upper Nalón in Asturias

SBB's 16.7 Hz railway plant between the Sihlsee and Lake Zurich a Altendorf

Two sets a Galgenbichl lift Malta water up to Kölnbrein; rebuilt for variable-speed operation 2019-2024

Vattenfall's circular basin on the Geest bluff, pumping straight out of the tidal Elbe

Pumps between Lake Matese, high on the massif, and the Volturno valley

Top stage of the Schluchsee cascade, working the Black Forest's Schluchsee against the Schwarza basin

Slovakia's first reversible-turbine plant, between the Ružín and Ružín II pools of the Hornád above Košice

Upper basin on Homole hill above the Vltava cascade; rebuilt with a single 45 MW reversible set in 1996

Transfers Hnilec water from Palcmanská Maša across the ridge into the Slaná basin - a 1953 inter-basin plant

The 1963 experimental unit where the reversible turbines for Ružín and Liptovská Mara were proven

The first pumped-storage plant in Czechia (1930), between the glacial Černé jezero and a small basin on the Úhlava