September 9, 2015

Climate Change Vulnerability Assessment of Ontario’s Electrical Transmission Sector


It is generally accepted that modern economies are fundamentally dependent on reliable and secure electricity systems.  Electricity supply interruptions can impact the delivery of other critical infrastructure and services, supporting public health and safety, and disrupt economic activity.  Understanding the critical importance of reliable electrical supply, and the need to prevent unsustainable investment in related assets and systems, Ontario’s Expert Panel on Climate Change Adaptation recommended a climate change risk assessment of the Province-wide electricity grid.  In March of 2012 the Environmental Commissioner of Ontario reiterated this recommendation.


Over the 2013-2015 time period, a study was overseen by the Power System Planning staff of the Ontario Power Authority — since amalgamated with Ontario’s Independent Electricity Systems Operator (IESO) — which made use of the PIEVC Protocol, an Engineers Canada-developed engineering vulnerability assessment tool, and related modules. The study included:

  • A screening-level climate change and engineering vulnerability assessment of a major electrical transmission station in southern Ontario, including high voltage electrical transmission components within the station and major high-voltage circuits into and out of the station.
  • A first order evaluation of the types of adaptation measures that could be used to help manage severe weather and climate change-related risks across a broader set of transmission system segments.


This paper contributes to a better understanding of the implications of climate change for the electrical transmission system in Ontario, with a focus on the high-voltage transmission system, by reporting on the study described above.