Burlington homes and businesses will see their electricity voltage dip for two short periods on Thursday, July 23, 2026, as the province runs routine tests of its emergency operating measures. The IESO is holding the grid-wide drill with local utility Burlington Hydro to make sure the system can quickly reduce demand if it ever runs short of supply.
The first test happens from 9 a.m. to 10 a.m. Eastern Time, with a 3 per cent cut in voltage. A second, larger cut of 5 per cent is planned from 1 p.m. to 2 p.m. If bad weather or other problems make the grid unstable that day, the tests will shift to July 30.
The IESO says most people will not notice anything. Voltage will stay within the normal range for everything from fridges to factory machines. The tests have been run every 18 months for more than 20 years, except for a pause during the pandemic. The last ones were in January 2025, when the 3 per cent cut lowered Ontario demand by about 1.4 per cent and the 5 per cent cut by about 2.1 per cent.
These drills let the grid operator check equipment and keep staff sharp on how to roll out the emergency measure. The test is not a sign that the lights are about to go out — Ontario added more than 1,000 megawatts of new power since last summer, enough to handle peak days.
For the roughly 68,500 Burlington customers served by Burlington Hydro, the short voltage dip is just a behind-the-scenes safety check.
