1856
First gasworks in Zurich put into operation in Platzspitz park next to the main station. Concessionaire was the engineer L. A. Riedinger from Bayreuth. The gasworks was designed for wood distillation only. 436 public and 3,000 private ‘flames’ were connected when the works opened.

1864
Enge gasworks put into operation, built by Basel-based engineering office Gruner.

1867
First works relocated to Limmatstrasse and put into operation. Cost: CHF 620,000; city of Zurich’s share: CHF 250,000.

1873
Branch works established in Hornbachstrasse in the district of Riesbach.

1886
City of Zurich takes over gasworks. The 30-year concession agreement with engineer L. A. Riedinger had expired, so the city acquired the gasworks in Limmatstrasse and the one in Riesbach for CHF 1,332,784.

1898
Gasworks in Schlieren put into operation. After a loan was granted, the works in Schlieren were built at a cost of CHF 7.8 million, constructed in record time of two years. Works inaugurated on 20 November 1898 with daily output of 501,000 m³.

1904–1908
Gasworks expanded to provide extra daily output of 105,000 m³. Second construction stage: Oven Building 2 and expansion of gas purifying systems.

1930–1934
Gasworks expanded to provide extra daily output of 205,000 m³. Third construction stage: chamber furnace facility, coal and coke preparation facility and expansion of gas purifying systems.

1942–1948
A gas wood preparation facility, including transmission systems, was built as coal supplies came to a halt during the Second World War.

1966
Gasverbund Ostschweiz AG (GVO) founded.

1968
Petroleum oil cracking plant built to overcome supply bottleneck. Gas network expanded in eastern Switzerland and supply to 12 partner works.

1969
Larger supply volumes to partner works required greater capacities. The spherical gas tanks with pressure of 16 bar were built.

1972–1974
Coal gasworks shut down in Schlieren. A variety of modifications and new buildings were undertaken before the shutdown, such as a gas detoxification system, a sulphur removal unit and the machine hall. Changeover from town gas to natural gas.

1974
Conversion to natural gas throughout GVO’s supply region, and cracking plant closed down.

1974
The Staffelbach-Schlieren supply pipeline connected Erdgas Ostschweiz AG to the Netherlands-Italy transit gas pipeline and thus to the integrated European system.

1993
Founded as Gasverbund Ostschweiz AG in 1966 and renamed Erdgas Ostschweiz AG, the regional company has a share capital of CHF 30 million, held by nine municipalities and three private natural gas suppliers.

2000
Demolition of three of the four gas holders.

2003
Renovation work on the last remaining gas holder.

2008
As proof of its high quality awareness, Erdgas Ostschweiz AG is certified to ISO standards 9001:2001, 14001:2004 and PIMS.

2009
Conversion of former oil pipeline in St Galler Rheintal – a complex, one-of-a-kind project in Switzerland – is completed on schedule within business year 2009 thanks to great effort. High-pressure pipeline is put into operation along the section between St Margrethen and Bad Ragaz. Now that this section is operating, Erdgas Ostschweiz AG is able to improve supply reliability in eastern Switzerland and the Rhine Valley significantly and further promote market development in this region. The project to take over and convert the crude oil pipeline decommissioned some ten years before takes several years to complete.

2014
Erdgas Ostschweiz AG unbundled network operation and procurement and founded a new company, Open Energy Platform AG. This means that Erdgas Ostschweiz AG has met key requirements of a deregulated natural gas market at an early stage.