Acceptable Black-Outs? Four Strategies for a Secure Electric Power System

This project aimed at constructing and describing security and preparedness strategies for the Swedish electric power supply. The work was conducted with experts with knowledge of the power system, preparedness and critical power consumers. In the study power board customers critical to society were identified. For each customer category the expert group has agreed on unacceptable durations for black-outs depending on type of disturbance in the power system and geographic area affected. The expert group also agreed that it is the responsibility of each function in society to be able to handle power disturbances up to six hours long. Four strategies of different character are presented: Increased power reserves at consumers;increased capability to prioritize consumers through technical control measures;increased robustness in the electric power system;faster recovery of the electric power system. The strategies cover different alternatives for handling power disturbances and their implications regarding measures and costs. Consequences of disturbances must have a serious impact on society to be considered. The work relates to the "HEL-project" at the Swedish Energy/Agency,the purpose of which is to create a mutual overall view and a public/private cooperation for all stakeholders on safety and preparedness in electricity supply.