TRIMET is overcoming the dogma that aluminium production must be based on a constant supply of energy. Their “Virtual battery” project aims to make the energy-intensive electrolysis process more flexible.

The electrolysis furnaces in TRIMET’s Essen plant would be used as a huge energy store, facilitating the integration of variable renewables into the power grid. The plant’s overall storage capacity is approximately 1,120 megawatt hours, comparable to a medium-sized pumped storage power plant.

If fully implemented, TRIMET’s four aluminium smelters could increase Germany’s pumped storage capacity of 40 gigawatt hours by a third.

TRIMET has already developed a controllable heat exchanger to allow flexibility, together with the University of Wuppertall. They are now investing €36 million for industrial-scale tests.