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Pelton turbine System Erlach: History

From the first application in 2004 to the first horizontal Pelton turbine with six nozzles in a power plant in 2022, eighteen years passed. Every step on this page rests on a document that can be produced.

This page is about System Erlach: the horizontal Pelton turbine with up to six nozzles designed by Josef Erlach. What holds for every Pelton turbine is marked “Pelton turbine” in the heading. The difference is explained in the overview Pelton turbine System Erlach.

Pelton turbine before System Erlach: horizontal with two nozzles, vertical with six

Lester Allan Pelton receives the patent for his turbine. The first machines are horizontal and have one or two nozzles.Viennahydro 2012, full paper, section 1
around 1960
Machines with up to six nozzles appear. For this, the shaft is set vertical.Viennahydro 2012, full paper, abstract

Why horizontal machines stopped at two nozzles is explained under Horizontal Pelton turbine.

System Erlach since 1955: apprenticeship, application, model, test, licence, power plant

Josef Erlach begins his apprenticeship at the Kaprun power plant.Frankfurter Allgemeine Zeitung, 13 September 2011
He joins Escher Wyss in Ravensburg and stays with the company, later Sulzer Escher Wyss, VA Tech and Andritz Hydro, for forty years.Viennahydro 2012, full paper, curriculum vitae
First application: the water drain system with guide rings, jointly with an institute of the University of Stuttgart. Priority 17 December 2004.Patent family WO 2006/066691, EP 1 828 596 B1
The first model with six nozzles on a horizontal shaft is built.Image data 18 June 2006, archive of Erlach & Erlach
Second application: the inlet system, inventors Josef Erlach and Thomas Staubli. Priority 3 July 2006.EP 2 035 689 B1
Voith Hydro becomes development partner.Viennahydro 2012, full paper, sections 2.5 and 5
from 2008
The machine runs as a model on the test rig of Lucerne University of Applied Sciences and Arts. It is the first model test according to the standard.Viennahydro 2012, full paper, sections 2.5 and 5
The patent for the water drain system is granted.EP 1 828 596 B1, granted 23 September 2009
Josef Erlach receives the IEC 1906 Award for his work in the standardisation of water turbines.Press release of the VDE, 29 November 2010
The Frankfurter Allgemeine Zeitung presents the machine. The patent for the inlet system is granted. Josef and Philipp Erlach found Erlach & Erlach GmbH.FAZ, 13 September 2011; EP 2 035 689 B1, granted 21 September 2011; commercial register Ulm
Voith becomes the first licensee for the Pelton turbine System Erlach.Viennahydro 2012, full paper, section 5
Presented to the professional community at Viennahydro in Laxenburg, 22 November 2012.J. M. Erlach, New Pelton Concept, full paper
Hidroenergia in Istanbul: presentation and Innovation Award of the European Small Hydropower Association.Conference paper Hidroenergia 2014
Article in the journal WasserWirtschaft.WasserWirtschaft 106 (2016), issue 10, pp. 18–24
The first machine of this design in a power plant goes into operation in Gerlos, built by Voith. In its own publication on it, Voith cites the presentation by Erlach from 2012.R. Mack, B. List, Viennahydro 2022
TU Wien publishes a study on distributors with axial inlet and names Erlach as the starting point.Hahn et al., Energies 16 (2023) 2737
Troyer AG presents the “Pelton Turbine System Erlach” in Flums.zek Hydro, October 2025, pp. 66–67
Paper by Josef and Philipp Erlach for Viennahydro, fourteen years after the system was presented at the same place.Viennahydro 2026, paper 157, presentation on 20 November 2026
Hall with a screen showing a slide of the presentation. In front of it, listeners and a photographer.
Viennahydro 2012 in Laxenburg, 22 November 2012: the presentation

System Erlach, the documented chain: origin and recognition rest on documents

The principle that allows a horizontal Pelton turbine to take six nozzles goes back to Josef Erlach. It was licensed, developed further and first built into a power plant in 2022.

How the principle works is explained under Pelton turbine System Erlach. The property rights in detail are listed under Pelton turbine patents, the works of others that refer to Erlach under Pelton turbine research.