December 4, 2025: European energy group Vattenfall said on December 1 it had signed a landmark 100MW/400Wh battery storage capacity deal for a facility under construction in the Netherlands.

Under a contract starting in January 2028, Sweden-based Vattenfall will have full operational control of capacity from the Leopard BESS project being developed by Giga Storage — helping mitigate imbalances in power generated by renewables such as wind and solar.

Giga Storage has already reached a final investment decision for the Leopard battery, which is under construction in the northern Netherlands and will have a maximum output of 300MW.

Vattenfall said it will be able to store up to 400MWh of energy in the battery and charge or discharge at a maximum capacity of 100MW.

This is Vattenfall’s third flexibility contract agreed in a short period. Earlier this year, the company contracted 50MW in the Netherlands and 55MW in Germany.

Erik Suichies, head of wholesale customers at Vattenfall, said: “As renewables take an increasingly prominent role in our energy system, the need for flexible capacity continues to grow.

“Batteries can respond rapidly to constant fluctuations, stepping in during shortages or storing energy when supply exceeds demand. This makes them a critical component of the energy system of the future.”