Abstract :
WITH BUT few exceptions, the requirements for extreme reliability and the economical use of resources in any electric system are diametrically opposed. It is not particularly difficult to design and operate a system to give any practicable degree of reliability of customer service if no consideration need be given to the price the customer must pay. On the other hand, if the service standards were lowered sufficiently, a system could be designed and operated with an over-all economy exceeding present values. The real problem is to obtain the required reliability with the maximum operating economy and the minimum of investment.