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Corporate IESO > Media > About Public Appeals > IESO Issues Power Warning for Tuesday, August 9th

IESO Issues Power Warning for Tuesday, August 9th

August 8, 2005

The Independent Electricity System Operator (IESO) has issued a Power Warning asking consumers to reduce their use of electricity on Tuesday, August 9th as sustained hot weather continues to put a strain on Ontario's electricity system.

Increasing temperature and humidity levels expected for tomorrow combined with continued limitations on supply, both from domestic generation and imports, are presenting a number of challenges for the IESO in managing the reliability of the electricity system.

As a result, consumers and businesses are being asked to reduce their electricity consumption between the hours of 8:00 a.m. and 8:00 p.m. tomorrow to reduce the strain on Ontario's power system.

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 and require proactive actions such as emergency purchases from other jurisdictions or voltage reduction on the Ontario system.

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

- Turning off all but essential internal and external lights;
- Setting air conditioners to 26 degrees Celsius or higher, or using fans as an alternative;
- Closing curtains and blinds to keep out the sun and retain cooler air inside; and 
- Delaying the use of major power-consuming equipment such as dishwashers, washers and dryers and swimming pool pumps until after 8:00 p.m.

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