IESO to Carry Out Routine Voltage Reduction Tests on January 21, 2025

The Independent Electricity System Operator (IESO) has announced that it will carry out routine voltage reduction tests on Tuesday, January 21, as part of mandatory testing of the IESO’s emergency operating measures. The test is an important tool for ensuring the reliability of Ontario’s electricity grid.

The test schedule is as follows:

• 3% reduction between 9:00 AM and 10:00 AM
• 5% reduction between 1:00 PM and 2:00 PM

Voltage reduction tests have three key purposes:

• To determine how much power can be reduced through the two levels of reduction
• To identify equipment problems so they can be addressed
• To help keep IESO and market participant staff familiar with procedures to execute voltage reductions and identify any deficiencies in the procedures that may need to be corrected

Impact on Customers:

The voltage reduction tests are expected to have minimal or no noticeable impact on the public as the voltages are still expected to be within established industry standards for electrical equipment used by residential, commercial and industrial consumers.

Read the full IESO news release and find more information about voltage reductions on the IESO website.