All electricity and gas supplying systems provide a certain level of security. Whether this level of security is adequate or not is however not easy to assess. There is a trade-off between security and costs as higher levels of security can only be reached with greater investments, while a less secure system is also less costly. Achieving an adequate level of security of supply needs the balancing between the benefits of increased security and the additional costs needed to realize it.

This paper aims to mitigate this problem by providing details and information on the demand side of security making calculations on the value of lost load for consumers in the natural gas market. The results of the paper could be used to evaluate investments and/or regulatory decisions that affect the level of security of supply, directing it closer to the theoretical optimal.