The underground gas storage facility Bernburg (Saxony-Anhalt) of VNG Gasspeicher GmbH (VGS) celebrates its 40th anniversary these days. The biggest and most flexible storage of the VGS was put into operation in 1974 with the initial injection of natural gas into the cavern 101. Today the cavern consists of 33 caverns with a total volume of one billion cubic meter (m³) natural gas. For comparison: The total capacity of all 6 underground storage facilities is 2.7 billion m³. With that amount of gas it is possible to provide gas for one whole year for approximately one million households.
The underground storage Bernburg is a cavernous storage. These are manmade, hollow spaces which have been created in vast underground salt deposits. The salt is dissolved with the help of water and transported above ground. “Our storage facility in Bernburg was enlarged steadily since the 70s, in cooperation with the local salt industry. The salt industry and their long term ensured ability to use our salt was always guarantor for us to develop the storage location Bernburg and to enlarge our capacities”, explains Dr. Volker Busack, technical executive director of VGS on occasion of the anniversary. He adds: “We also have to thank the city of Bernburg, the surrounding communities and our technical service providers for the good and fair collaboration. We look forward to a future trustful cooperation.
Steady enlargement of the storage capacities
1968 the first plans to build the underground storage facility Bernburg were made. It was created to compensate the seasonal fluctuations of gas from the beginning of the first gas supplies from Russia in 1973 and also to have a reserve for possible interruptions of supply caused by technical accidents. Furthermore the storage was kind of a pilot project, in which German and Russian gas experts gathered new experiences in the storage of natural gas within caverns.
In the 1970s and 1980s the Storage in Bernburg was used exclusively to store natural gas and besides enlarged steadily. Started with two caverns in 1973, there were six caverns, with a total volume of 400 million m³, in the mid-80s already.
In 1990 the complex modernization of the above-ground and underground facilities in Bernburg started. This modernization included the automatization of the existing compressor facility, new construction of the gas control lines, renewal of the gas drying plant, renewal of the measuring facility and a new heating house. The above-ground facilities were renewed as well: From 2010 to 2011 two new ejector units were put into operation. These facilities increase the injection rate while they decrease the energy consumption. In the last year the gas quality measuring facility was renewed successfully. “The new technical facilities made our storage in Bernburg not only one of the most modern storage facilities in Germany but also one of the fastest”, says Dr. Busack. By now, it is possible to inject 12 million m³ and to withdraw 35 million m³ of natural gas every day. For comparison the storage only had maximal injection rate of 7.2 million m³ in 1973.
40 years of safety and security of supply
“For 40 years now, our employees have proven how a safe and at the same time efficient operation of an underground storage works. That are at the same moment 40 years in which they had a significant contribution to the security of gas supply in Germany”, explains Hans-Joachim Polk, chairman for infrastructure and technical affairs of the VNG – Verbundnetz Gas AG (VNG). Polk, among other things, takes the responsibility for the business area of gas storage within the VNG-Group. Meanwhile the employees are supported by modern methods for long-distance distribution and by an integrated quality- and safety management-system. “In the past 40 years we have proven, that the VGS with its infrastructure –including Bernburg- is in a very good position and due to that the security of supply can always be ensured”, says Polk.
With a view on the prospective 40 years, Polk sees the storage facility in Bernburg and the other storage locations of the VGS in a good position. “Natural gas is, especially because of its infrastructure the ideal partner for the energy turnaround. In our gas storages, climate neutral bio natural gets stored already. Prospectively the storages are also able to store synthetical natural gas, gained from wind- or solar power”, he says.
Long tradition of gas storage
The VGS respectively VNG looks back on a long tradition of gas storage. Already in 1964 the first underground storage facility in Brandenburg, today however closed, was put into operation. 1973 the gas storage in Kirchheilingen in Thuringia started, one year later Bernburg followed. Two more storages in Buchholz (Brandenburg) and Bad Lauchstädt (Saxony-Anhalt) were put into operation in 1975. The latest storage project of the VGS is located in Etzel (Lower Saxony). Together with Gazprom the VGS also erects the underground storage facility Katharina. Till 2025 gradually twelve caverns will be put into operation. The total volume will be approximately 600 million m³.
Till 2012 the VNG was responsible for the marketing, operation, maintenance and development of their underground storage facilities. In the course of the changed legal parameters the VNG Gasspeicher GmbH was founded in 2012.
Background: Underground Storage Facility Bernburg
The storage facility consists of a cavern field with 33 salt caverns. The above-ground facilities are equipped with a compressor system with four piston compressors, five gas dehydration plants, eleven measurement facilities and ultrasonic measuring equipment. The underground gas storage Bernburg is connected to three gas pipelines. The network operator is the ONTRAS Gas Transport GmbH, connecting the storage to the GASPOOL market area. The caverns of the storage facility Bernburg are located at a depth (mining depth) of 500 - 700 meters. The 33 caverns are operated at a maximum pressure of 96.4 bar. They provideabout 1.03 billion cubic meters of working gas volume.