A major factor in the planning of a country’s electricity system is the cost of the non supply of electricity. This cost can change over time and depends inter alia on the existing back-up system and the economic cost of the damages that are caused due to the non supply of the energy. A study conducted in 1993 showed that the cost of one KWH of non supplied electricity to the Israeli market is $6.50-7.20. In August 2007 an external consultant calculated this cost to be $25 per KWH not supplied