With that comes more pressure on electric companies to give an honest accounting of their preparedness. State regulators also are seeking answers. Y2K experts say some problems won't be found and fixed, and that some fixes won't work as designed. The extent of the fallout could vary, depending upon which companies and agencies experience failures, and precisely where those failures occur. Any failures at individual utilities could be magnified by the nature of the power grid.
Electricity is distributed through regional pools that buy and sell power from dozens of suppliers.
Any problem in the chain has the potential to adversely impact all. If a single utility had a problem, it probably would not be significant. You can have a series of problems that by themselves wouldn't pose a threat but when you put them together could represent a significant problem. Utility B may have a problem with a transmission line. Utility C has a problem with a transformer.