
Despite their high construction costs, pipelines are imperative for the transportation of huge quantities of natural gas and are considerably more efficient than delivery by tank ship or road tanker, which requires the natural gas to be liquefied prior to transportation.
An extensive European pipeline network (over 360,000 kilometres in Germany alone) enables the delivery of natural gas to the end customers in their homes.
Pipelines of different diameters run through different corridors from Siberia, through Eastern Europe, to the Western European natural gas trading companies and German utilities.
It is also possible to transport gas, for example that produced by offshore platforms, by tank ship. For this purpose, the gas is cooled down to between –162 °C and –164°C. At this temperature, gas turns to liquid (LNG) and takes up only 1/600 of its original volume. When unloading the cargo, for example, 125,000 m3 of natural gas in its liquid state is regasified into 75 Mm3 of natural gas in its gaseous state – enough to supply a city of 300,000 inhabitants for a year.
On the spot, gas is not always passed on to the end customer immediately. This is especially due to the fact that the average daily and annual natural gas consumption is subject to great fluctuation. Particularly because there is no need for heating in the summer season, natural gas consumption is less than during the winter. Differences in natural gas consumption also occur between day and night. As natural gas is, however, regularly delivered through the pipelines, it is required to store it in underground storage facilities. The quantities so stored are available in the winter season. At depths between 1,000 and 3,000 meters, gas is stored either in depleted reservoirs or in salt caverns. The latter are created by drilling and leaching out cavities in salt formations which is a challenging procedure.