Grimsel 4
Energy You Cannot See — CHF 300 million, entirely underground, deep in the Swiss Alps.
The largest invisible construction project in the Swiss Alps — as a 360° experience.
In June 2026, Kraftwerke Oberhasli AG (KWO) begins construction of Grimsel 4 — a fully underground pumped storage power station between the Grimselsee and Räterichsbodensee reservoirs in the Swiss Alps. CHF 300 million. Completion 2032. Nothing of it will ever be seen from the outside.
That is precisely what makes it the perfect 360° film project: a structure being built while remaining entirely invisible. Tunnels deep in the rock. Underground caverns that the public will never enter. Two Voith pump turbines delivering 140 MW of balancing power — stabilising the Swiss grid when the wind drops and the sun goes down.
Grimselsee / Räterichsbodensee, Grimsel region — Canton of Bern, Switzerland Foto: Kraftwerke Oberhasli AG / David Birri .
Avocado360 is developing a 360° documentary that shows the construction from the inside — making tangible the energy transition story being written inside this mountain right now.
The full project page with details on content, team and partnership opportunities is coming soon. We have established initial contact with the KWO project team.
Interested in the project?
We welcome conversations at any stage.