Visualization software packs a large amount of information into a single computer-generated image, enabling viewers to interpret the data more rapidly and more accurately than ever before. This kind of software will become still more useful, even indispensable, as electricity grids are integrated over ever-larger areas, as transmission and generation become competitive markets, and as transactions grow in number and complexity.

Tracking and managing these burgeoning transaction flows puts operating authorities on their mettle. While the electric power system was designed as the ultimate in plug-and-play convenience, the humble wall outlet has become a gateway to one of the largest and most complex of man-made objects. For example, barring a few islands and other small isolated systems, the grid in most of North America is just one big electric circuit. It encompasses billions of components, tens of millions of kilometers of transmission line, and thousands of generators with power outputs ranging from less than 100 kW to 1000 MW and beyond. Grids on other continents are similarly interconnected.

In recent years, a further complicating factor has emerged. Along with the broadening integration of power systems has come the increased transfer of of large blocks of power from one region to another. In the United States, because of varying local power loads and availability, utilities purchase electricity from distant counterparts and independent suppliers, exploiting price differentials to economize on costs. For one, the Tennessee Valley Authority, which provides power to more than 8 million residents in seven states using over 27 000 km of transmission lines, handled a mere 20 000 transaction requests through its service territory in 1996, compared to the 300 000 in 1999.

The net effect is that data once of interest mainly to small cadres of utilities now must be communicated to the new entities being established to manage restructured grids. In the United States, that means independent system operators (ISOs) and regional transmission organizations (RTOs), which have to be able to grasp fast-changing situations instantaneously and evaluate corrective strategies nearly as fast.

Power marketers' needs, too, be-come more urgent, as access to the grid is opened and competition among generators is introduced across the United States and elsewhere. They must be able to see just how much existing and proposed transactions will cost, and the availability of electricity at any time and any point in the system.

Finally, concepts like power flow, loop flow, and reactive power, which once mattered only to the engineers directly involved in grid operations, now must be made intuitive. This is because they must be communicated to public service commissions and the consumer-voters to whom such boards are answerable.

In short, whether the client/user is a power marketer, a grid operator or manager, a public authority, or a member of the public, power system visualization tools can aid their comprehension by lifting the truly significant above background noise. Such tools can expedite decision-making for congestion management, power trading, market organization, and investment planning for the long term.

The visualization tools illustrated here are available from PowerWorld Corp., Urbana, Ill. Visualization tools offered by others rely on updated text. ABB, Alstom ESCA, GE Harris, and Siemens, for example, offer tools that are part of larger energy management systems packages.