ISO New England forecasts adequate electricity supply for summer 2003

Outlook remains cautious for areas affected by transmission constraints

HOLYOKE, Mass., May 7, 2003 — ISO New England Inc., the operator of the region’s bulk power system and wholesale power exchange, has released its summer capacity outlook for New England.

ISO New England forecasts that the projected installed generating capacity of 31,000 megawatts (MW) of supply should be sufficient to meet regional demand this summer. However, localized problems in Southwest Connecticut and Northwest Vermont may require steps to balance supply and demand in those areas.

“Significant efforts have been made across New England to increase energy supplies and keep pace with growing demand,” said Stephen G. Whitley, ISO New England Inc.’s senior vice president and chief operating officer. “As a result of this continued development, we expect to have adequate supply to meet demand this summer. Barring any unforeseen transmission or generation outages, we do not anticipate any region-wide public appeals for conservation.”

Summer peak demand for New England is forecasted to reach 25,120 MW on at least one day this summer under normal weather conditions, around 91 degrees Fahrenheit. Extreme weather conditions, such as an extended heat wave of approximately 95 degrees Fahrenheit, could drive peak electrical demand to 26,630 MW. New England’s summer electricity use typically ranges between 19,000 MW and 23,000 MW under normal weather conditions. The current record for electricity usage is 25,348 MW, which was set on August 14, 2002.

“Despite the adequate supply forecasted for the region as a whole, the outlook for Southwest Connecticut and Northwest Vermont remains cautious due to the inability of transmission lines in those areas to carry enough power to meet local demand and transmission line outages,” noted Whitley. ISO New England forecasts that capacity deficiencies could occur in Southwest Connecticut up to six times this summer. In Northwest Vermont, no capacity deficiencies are forecasted currently, but ISO New England is monitoring system conditions in that area because of localized transmission problems.

On days of a capacity deficiency, a series of actions is implemented, known as the New England Power Pool’s “Operating Procedure No. 4” (OP 4), to help balance supply and demand and maintain the reliability of the bulk power system. For example, one measure allows the ISO to utilize mutual assistance agreements with neighboring power systems to purchase emergency power if the bulk power grid’s operating reserve falls below required levels. Another measure calls upon the public to help by temporarily conserving its use of electricity. Last year, ISO New England implemented OP 4 on six occasions.

For the seventh straight year, ISO New England will be using its public appeal program when issuing conservation requests to reduce demand on the power grid. Modeled on the National Weather Service’s storm advisory system, the emergency warning system has two levels of public appeal: Power Watch and Power Warning.

A Power Watch is invoked to request that customers voluntarily reduce electricity use, in ways consistent with health and safety, when the region’s electricity supplies are expected to be tight. A Power Warning is a more urgent appeal issued when there is a concern that utility companies may have to disconnect customers to reduce local demand on the power grid so that the integrity of the entire power grid is maintained. In the past, these public appeals have been extremely effective in reducing electricity demand.

For more than five years, ISO New England Inc. has been the not-for-profit corporation responsible for the day-to-day reliable operation of New England’s bulk generation and transmission systems with an installed capacity of approximately 31,000 megawatts. In addition to operating the bulk power grid, ISO New England is the administrator of the region’s wholesale electricity marketplace and the Open Access Transmission Tariff on behalf of the New England Power Pool.