The Netherlands’ aim is for 14% of the energy consumption to come from sustainable sources by 2020. This energy consumption covers transport, industry and electricity. For the last category this means that, as we approach 2020, around one-third of the electricity in the Netherlands must be generated using sustainable practices. Given that the wind is not always blowing and the sun only shines during the day, a supplementary electricity source is necessary which can be switched on and off easily and is economically viable. Natural gas can be used like this as a source for electricity, but only if the gas is flexibly available, for which gas storage is essential. Gas storage therefore helps in this way in the transition to sustainable energy.