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Corporate IESO > Media > About Public Appeals > IESO Declares Power Warning with Expected Loss of Nanticoke Generation

IESO Declares Power Warning with Expected Loss of Nanticoke Generation

June 24, 2005

The Independent Electricity System Operator (IESO) is asking consumers to reduce their use of electricity with the expected loss of almost 4,000 megawatts (MW) of generation from the Nanticoke Generating Station.

Consumers and industries are being asked to immediately reduce their electricity consumption. This warning is in effect until 10:00 p.m. EDT.

Power Warnings are issued by the IESO during periods of high demand for electricity, when supplies of reserve power are low. Any further reduction in transmission or generation availability or any increase in demand could create shortfalls of electricity. If all sources of supply are exhausted, the IESO will take protective actions such as a system voltage reduction, or rotating cuts to supply. In these circumstances, no additional public notice may be possible.

The need to reduce electricity use is particularly significant in the Greater Toronto Area (GTA) and areas west of the GTA due to high loads on transmission lines in the Niagara Region and southwestern Ontario.

Consumers and businesses can reduce the demands on the electricity system by immediately:

* Turning off all but essential internal and external lights;

* Set air conditioners to 26 degrees Celsius or higher, or use fans as an alternative;

* Close curtains and blinds to keep out the sun and retain cooler air inside; and

* Delay the use of major power-consuming equipment such as dishwashers, washers and dryers and swimming pool pumps until after 10:00 p.m.

The IESO is responsible for managing Ontario's bulk electricity system and operating the wholesale electricity market. For more information, visit