Electrical power is perhaps the most essential raw material used by commerce and industry today. It is an unusual commodity because it is required as a continuous flow- it cannot be conveniently stored in quantity - and it cannot be subject to quality assurance checks before it is used. The reliability of the supply must be known and the resilience of the process to variations must be understood. In reality, of course, electricity is very different from any other product – it is generated far from the point of use, is fed to the grid together with the output of many other generators and arrives at the point of use via several transformers and many Kilometers of overhead and possibly underground cabling. Where the industry has been privatized, these network assets will be owned, managed and maintained by a number of different organizations.
Assuring the quality of delivered power at the point of use is no easy task – and there is no way that sub-standard electricity can be withdrawn from the supply chain or rejected by the customer. From the consumers’ point of view the problem is even more difficult. There are some limited statistics available on the quality of delivered power, but the acceptable quality level as