Black starts

A black start ensures minimal downtime of power supply for Canadians after a significant outage event by enabling timely restoration of power for grid operations.


In the event of an outage, a powerplant operator can typically still rely on the electric grid to keep internal systems like lights, data systems, telecommunication equipment, as well as other auxiliary equipment, to start a generating unit and keep it running.

However, in the event of a widespread outage caused by equipment failure or natural catastrophes, electric grids could go completely out of service, unable to supply any power. This situation drives the need for a powerplant to start a generator unit from a completely non-energized state, without the using external power from the grid. This provisioning is called a “black start.”

A black start occurs when capable plants/units provide the energy to jump start the electric system recovery. In other words, to provide the first minimum amount of electric power that is needed to activate the power grid (including other powerplants and the transmission and distribution system). An ideal black start unit needs minimal time, fuel, and equipment to restart. These characteristics have paved the way for several power generation technologies such as diesel generator sets, hydroelectric units, combustion turbine units, combined cycle units, utility-scale renewable energy power sources, etc.

Case studies

  • In October 1987, there was a regional black start in the wake of a powerful hurricane that hit Sussex, England. The storm damage left Kent and Sussex disconnected from the National grid – however, due to black start contingency plans, most people barely noticed. Kingsnorth Power Station restored power to the area, and it ran independently, cut off from the rest of the grid, until repairs enabled it to be connected again.
  • On August 14, 2003, Toronto experienced a blackout that paved the way for all regional reliability councils to re-evaluate their procedures and plans to ensure an effective black start and restoration capability within their region.

Did You Know?

    • For reliability to be maintained during a black start restoration process, plant operators in North America follow standards set by regulating bodies like the North American Electric Reliability Corporation (EOP-005-3,006-3,009-3) and Federal Energy Regulatory Commission.
    • Since 2019, the National Grid in the UK invested in several trials and pilot projects to develop generation capabilities from renewable sources to create a black start process. A similar initiative is also being discussed in Germany