Failures in medium-voltage power cables and their components cause a large proportion of annual power service interruptions, especially in high-density urban areas. Locating and repairing weak...
The nation's critical electric infrastructure is still too vulnerable to outages.
The Sept. 12, 2005, electricity blackout of most of the city of Los Angeles demonstrates the continuing vulnerability of the nation's electric infrastructure. It also reinforces the fact that the main protection of our vast network comes from the ability of the local utility company to rapidly locate, analyze, and repair breaks in the network, as occurred in Los Angeles, where service was restored quickly after the outage.
Although the cause of the Los Angeles outage was accidental, it exposed a glaring weakness: cable line breaks are an attractive, easy target for terrorists, because the U.S. electric network has thousands of miles of unguarded transmission and distribution lines. The first line of protection for our electric infrastructure comes from a highly trained workforce dispatched quickly with sufficient knowledge, equipment, and spare parts to handle multiple occurrences at the same time.
A second line of protection should come from an analysis and strengthening of the weaker points in the electric grid. Local electric grids will need additional investment at key points to minimize the possibility of a breach at a single location, which, as the Los Angeles case shows, can bring down an entire city or region.
The Need for Backup Systems
The Los Angeles outage also reminds us that facilities such as hospitals, police, and fire departments must have on-site backup power units capable of handling all of their critical functions. In the future, units that were "back-up" generation could become part of a network of distributed generators adding reliability to the grid. This development may, in many states, be dependent upon new regulatory policies with respect to the connection rules and tariff consideration of distributed generation.
Regardless of the root cause of the Los Angeles outage, the fact that a cut cable at a single location could bring down the entire city grid is reason for concern. Yet it is comforting to know that electric utility employees brought most of the system back up in two hours because the necessary materials were available and nearby.
That may not be the case everywhere in the United States. Maintaining a reserve of spare parts sufficient to meet all contingencies carries a cost, especially with today's higher demands in light of the threat of terrorism.
Our electric infrastructure should be more resilient, and not so vulnerable at a single point. Engineers must identify critical points in need of reinforcement on each distribution and transmission system. Historically, the nation's engineers have not been reluctant to design redundancy and resilience for improved reliability into the electric grid. They can and are willing to do so. However, as long-time participants in regulation are aware, the problem has been, and will continue to be, convincing the ratepaying public that additional investment is required to fund these improvements. Such an investment may result in the increased electric rates.
Infrastructure Security: Who Pays?
Electric rates are increasing in many parts of the country because of the rising cost of natural gas and coal, the