Power supply shortages possible, MIT researchers say


The move toward deregulation in the electric power industry may one day result in lower prices to users, but in New England the incipient competition may exacerbate an existing short-term energy supply problem, resulting in summer "brownouts" (reductions in voltage) due to high demand from air-conditioning usage. Researchers at the Energy Laboratory, who have been studying the complex control aspects of a deregulated system, have identified some specific tools that may help power grid managers minimize the extent of brownouts and maximize efficiency.

The researchers also say that the prospect of brownouts, which can cause damage to some appliances, demonstrates a largely ignored problem with designing a competitive power system on a network built for regulated operation.

Even under regulation, New England utilities can't bring in cheap replacement power from the Midwest during peak demand periods because of inadequate transmission capacity. Obtaining power from nearby Quebec is not an option either, the researchers say, because technical incompatibilities could have an adverse affect on power system reliability.

The utilities will not be any more able to acquire outside power when they are unregulated, and the industry is moving rapidly in that direction, because the technical constraints will remain in the system. Improving the system is viewed as costly.

This underscores what Marija D. Ilic, a senior research scientist in the Department of Electrical Engineering and Computer Science, calls a "particularly relevant problem which is barely paid attention to in the present debate"-and that is the development of economic incentives for the use of high-technology systems that can provide flexibility in managing available supply when demand peaks.

Dr. Ilic is leading the Energy Lab project with funding from the Department of Energy. The work is relevant for New England, where brownouts are virtually assured unless the region's transmission grid is enhanced so that power can be brought in during periods of peak demand.

The fact that three major nuclear plants in Connecticut were recently ordered out of service by the Nuclear Regulatory Commission because of safety concerns makes the region's problem even more acute. The plants produced as much as 45 percent of the electricity used in the state on a typical day last summer, and some of the power was used by other states in the region.

Partial improvements in the grid's operational flexibility can be achieved without building new lines by using what the MIT researchers call "3C" technologies-computers, controls and communications.

Further enhancements can be achieved by longer-term investments in devices that can act as "valves" capable of re-routing power flows from one path on the grid to another. These are costly devices, called flexible AC transmission systems (FACTS).

However, 3C's vital role in the transition from a fully regulated industry to one largely unregulated has been underestimated, both by the industry and government regulators, the MIT researchers have found. They suggest that Canadian or midwestern power could provide a reserve for New England, if the grid is enhanced using 3C tools.

"If we could import 3,000 megawatts of power to Connecticut from Canada or the Midwest, the Connecticut problem could be resolved," Dr. Ilic said. "A flexible transmission grid could play an enormous role under competition, given the right incentives, and it is potentially less expensive to enhance the New England grid than to rely on expensive local generation from nuclear plants, for example."

Transferring electric power across a large geographical area is an enormous technological challenge. A major system blackout that started with an unplanned outage of a transmission line recently affected seven western states.

The research points out the need for the industry to explore "the possibilities offered by enhancing the grid and eliminating transfer limitations" and for regulators to devise economic incentives "based on the value of the technologies to the system, which will encourage their development," Dr. Ilic said.

The researchers also hope their work will prove to be an impetus to the industry to make better use of older power plants as backup units, providing a way for the recovery of what are called "stranded costs," the expenses related to older plants and equipment whose usefulness has become minimal because of their outdated technology or because of a change in consumer demand.

"We hope our work will play a role in helping the industry achieve the advantages of competition while maintaining high reliability economically," she said.

Dr. Ilic is the author of a paper entitled "A Summer of Shortage: Benefits of Deregulation, But Who Pays For Reliability?" It will appear in Public Utilities Fortnightly this month. She and her former PhD student Shell Liu are co-authors of a recent monograph, "Hierarchical Power Systems Control:Its Value In A Changing Industry," published by Springer-Verlag in a series on advances in industrial control.

A version of this article appeared in MIT Tech Talk on July 24, 1996.


Topics: Energy

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