Basic data

Capacity: 400 MWh – 6.400 MWh
Power: 100 MW – 800 MW
Efficiency: 80%+
CAPEX: €140/KWh – €500/KWh (depends on size and geology)
Lifetime: 100+ years, with unchanged performance


Often the cost/kWh is compared with that of batteries, which are now cheaper than in previous years. The CAPEX for batteries listed in the latest Lazard LCOS report* is $225-$469, which is quite similar to the manufacturing cost of Gravity Energy AG’s Gravity Power Pump Storage (GPPS).

But the CAPEX is a poor comparison. Batteries do not scale well. GPPS become cheaper/kWh the bigger they get. Batteries do not do this! Batteries also wear out much faster than GPPS and have a lower efficiency.

The LCOS tries to consider all life cycle costs of a storage system, not only the capital costs, and thus illustrates the cost advantage of GPPS much better. The LCOS for batteries is $165-$305/MWh of released energy or 16.5 to 30.5 $cents/kWh (depending on assumptions). The LCOS model for our GPPS shows 17.3 $cents/kWh on the smallest scale (400 MWh) and 2.6 $cents/kWh on the largest scale (6400 MWh), so large GPPS are about 6-12 times better than batteries in terms of storage costs.

* Lazard’s Levelized Cost of Storage Analysis, ver.5.0 from Nov. 2019