Vandezande was responsible for the design, construction and start-up of 2 x 220 kW VDZ Hydropower screws on the river Alz in Höllthal (Germany).

Two large screws capable of turbining the available river flow of 21 m³/s at a high efficiency rate and in an extremely fish-friendly way was the best possible technical/economical solution for this site.

The screws each have a diameter of 4300 mm, are equipped with 5 helices and weigh 35 tonnes assembled in the steel screw trough.