November 1973: hardly a car in sight on Germany’s motorways. Due to the conflict in the Middle East, the OPEC countries impose an oil boycott.

January 2009: the spectre of freezing living rooms is at large in Germany. The energy dispute in Eastern Europe escalates. Russia turns off the supply of gas to Ukraine and Belarus. Transit pipelines to Western Europe remain largely empty.

The oil crisis and gas dispute make it absolutely clear – the globalisation of the energy supply loses much of its appeal when dependencies on imports arise. Calls for long-term supply security follow hot on the heels of any first-hand experience of supply bottlenecks.

Stadtwerke Kiel has adopted a forward-looking approach by storing natural gas in caverns. The advantage here is that unexpected supply shortages can be absorbed and consumption peaks arising at short notice in the winter months can be offset. What’s more, procurement costs can also be optimised by purchasing the gas at times of low consumption, such as the summer months.

In Rönne, a district of Kiel, engineers have been digging deep to maintain a secure supply of natural gas for nearly 40 years now. The first gas storage facility was commissioned here in 1971 already and was followed in 1996 by a second larger cavern. A further large-scale storage facility capable of holding 70 million cubic metres of natural gas is due to be completed by 2013. Storing gas on this scale requires specific geological formations. At a depth of between 650 metres and
1 800 metres, solution mining creates a cavity of 500 000 cubic metres which is surrounded and sealed by fixed soil formations. Using high-pressure compressors, the natural gas is compressed many times over and then stored safely in the depths of the earth.