How Spain's electricity storage is evolving
Electricity storage is not a single technology. It combines hydraulic pumping and batteries with very different roles.
This piece shows how the charging and discharging of stored electricity has evolved and what share it accounts for of peninsular demand.
In 2024, hydraulic pumping delivered 5.458 TWh of electricity and batteries 0.009 TWh.
Together, storage represented 2.21% of peninsular demand in 2024.
Delivery of stored electricity
Pumped hydro turbining is the main delivery source. Batteries are still very small in absolute terms, but have grown rapidly in recent years.
Storage delivery by technology (TWh)
Source: REE - REData API
Storage charging
Charging (consumption) for pumping exceeds discharging because the cycle efficiency is below 100%. This cost is the price of the flexibility service.
Storage charging by technology (TWh)
Source: REE - REData API
Net storage balance
The negative balance shows that storage always consumes more than it delivers (cycle losses). The absolute value indicates the energy cost of flexibility.
Net storage balance (TWh)
Source: REE - REData API
Delivery breakdown in 2024
Hydraulic pumping dominates storage delivery. Batteries represent a very small fraction, despite recent growth.
Storage delivery breakdown (2024)
Source: REE - REData API
2024 operational summary
| Concept | Value |
|---|---|
| Pumped hydro turbining (delivery) | 5.458 TWh |
| Batteries (delivery) | 0.009 TWh |
| Pumping (charge) | 8.664 TWh |
| Batteries (charge) | 0.012 TWh |
| Net balance | -3.208 TWh |
| Peninsular demand | 247.42 TWh |
| Delivery / demand share | 2.21% |
What the data tells us
1 Hydraulic pumping delivered 5.458 TWh in 2024, far above batteries (0.009 TWh).
2 Storage accounts for 2.21% of peninsular demand — a modest but growing role.
3 A net negative balance is normal: storage always loses energy in the cycle, but provides system flexibility.