◊ This is part of the ‘history’ series of articles ◊
Certain historical events and phenomenon are worthy of mention in any discussion of blackouts even though they haven’t directly caused one in Ontario – yet.
The Carrington event
On September 1, 1859 our sun experienced a solar Coronal Mass Ejection (CME) which hit the Earth’s magnetosphere and induced the largest geomagnetic storm on record.
An amateur astronomer, Richard Carrington, noticed a peculiar disturbance on the sun that day while using his observatory at his country estate outside of London England. A cluster of dark sun spots erupted with two bright white flashes lasting approximately 5 minutes before disappearing. In a matter of hours the impact of the sun’s burst would be felt world-wide.
In 1859 we did not have electrical grids, however we did have the telegraph. That night, telegraph communications began to fail with reports of sparks, operators experiencing shocks and even some fires. The aurora borealis was so bright in the middle of the night that people mistook it for dawn. It became known as ‘the Carrington event’ after the amateur astronomer who witnessed the solar event that caused it.
Why do we care about a CME or ‘Carrington event’?
If we were to experience the 1859 event in this century, parts of the electrical system, telecommunication, computer, electronic and satellite infrastructure would not survive. It would cause unimaginable social and economic damage which would take decades to recover from – if at all. We know from ice core samples and tree-ring carbon-14 analysis that Carrington events have happened in the past, so it’s just a matter of time until the next one. Electricity Reliability Organizations have been working on an action plan to mitigate damage should this happen in the future. Without a plan in place, the consequences could be catastrophic. It falls into one of many doomsday scenarios.
Fortunately, North American electricity reliability organizations have proactively put measures in place to safeguard against worst-case scenarios.
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A solar coronal mass ejection or CME is associated with solar flares. It releases large quantities of matter and electromagnetic radiation which are harmful to our planet. A CME may be considered one form of an electro-magnetic pulse (EMP)
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Geomagnetic Disturbance intensity scales – the Kp-index and NOAA G-scale
A standardized way to quantify disturbances to the earth’s magnetic field was introduced in 1939 by Julius Bartels and called the K-index. The Kp-index (the planetary K-index) is the calculated average K-index from 13 geomagnetic observatories at mid-latitude locations.
The National Oceanic and Atmospheric Administration (NOAA) has defined a geomagnetic storm scale that ranges from G-1 to G-5. The NOAA official space weather scales in pdf format are here.
The Kp-index and G-scale cross reference with characteristics (ref. SWPC):
| Kp Index Value | G Scale |
Term | Characteristics |
| 0 | G0* | Quiet | Aurora oval mostly to the north of Iceland. Faint aurorae visible in photographs, low in the northern sky |
| 1 | G0* | Quiet | Aurora oval over Iceland, faint and quiet aurorae visible to the unaided eye low in the northern sky |
| 2 | G0* | Quiet | Auroras readily visible and become brighter and more dynamic |
| 3 | G0* | Unsettled | Bright auroras visible at zenith. Pale green colour more obvious |
| 4 | G0* | Active | Bright, constant and dynamic northern lights visible. More colours start to appear |
| 5 | G1 | Minor Storm | Bright, constant and colourful aurora display, red and purple colours appear. Aurora coronae likely
Power systems: Weak power grid fluctuations can occur. |
| 6 | G2 | Moderate Storm | Moderate storm – Bright, dynamic and colourful aurora display. Aurora coronae likely. Memorable to those who witness them
Power systems: High-latitude power systems may experience voltage alarms, long-duration storms may cause transformer damage. |
| 7 | G3 | Strong Storm | Bright, dynamic and colourful aurorae. Visible in the southern sky. Aurora coronae very likely
Power systems: Voltage corrections may be required, false alarms triggered on some protection devices. |
| 8 | G4 | Severe Storm | Bright, dynamic and colourful aurorae. Aurora seen around 50° latitude
Power systems: Possible widespread voltage control problems and some protective systems will mistakenly trip out key assets from the grid. |
| 9 | G5 | Intense Storm | Intense storm – Aurorae seen around 40° latitude. Red aurorae and coronae very likely. Most often caused by powerful coronal mass ejections
Power systems: Widespread voltage control problems and protective system problems can occur, some grid systems may experience complete collapse or blackouts. Transformers may experience damage. |
*Note: G0 is not commonly used but cross references to Kp values less than 5
Hydro Quebec, 1989
In March of 1989 our Sun experienced severe to extreme solar storms. On March 13, the geomagnetic disturbance was sufficient to knock out power lines in Quebec and cause a 9 hour outage on their transmission system. Estimates put the intensity of the storm at Kp-9. The extremely long transmission lines from hydro plants near James Bay along with the high resistivity of the Canadian Shield increased Hydro Quebec’s vulnerability to the geomagnetically induced currents (GICs) that resulted from the solar event. Ontario routinely exchanges energy with Quebec, however the two systems are not operated in parallel and Ontario had minimal impact from the event. See the NASA article here.
Following the 1989 solar event, Hydro Quebec made several modifications to their system to avoid it happening again.
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Solar disturbances occur in cycles called the solar magnetic activity cycles. Each cycle takes approximately 11 years where solar flare activity goes from minimum to maximum. Cycles have been observed as short as 9 years and as long as 14. The visual effect of solar flare activity is seen on earth as the aurora borealis or Northern Lights. Very high intensity solar storms can impact electrical grids and cause power outages. In the worst case geomagnetically induced ground currents can saturate transformer cores causing catastrophic power equipment failures.
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Hydro One preventative measures, 2012
With growing concerns about the impact of solar activity, Hydro One installed GIC detection devices in 2012 at strategic locations across Ontario’s transmission system. The preparedness plan was presented at the Critical Infrastructure Protection and Space Weather Workshop in Ottawa in 2012 by Luis Marti and available from NERC.
North American Reliability Organization measures
In 2013, the Federal Energy Regulatory Commission (FERC) Order No. 779 directed the North American Electric Reliability Corporation (NERC) to develop reliability standards for geomagnetic disturbances. Since Ontario recognizes NERC as a Standards Authority, compliance with their standards is mandatory.
In 2014, FERC approved approved Reliability NERC Standard EOP-010-1 “Geomagnetic Disturbance Operations“. The purpose of EOP-010-1 is to mitigate the effects of geomagnetic disturbance (GMD) events by implementing Operating Plans, Processes, and Procedures.
In 2016, FERC approved Reliability Standard TPL-007-1, Transmission System Planned Performance for Geomagnetic Disturbance Events. The purpose of TPL-007 is to establish requirements for Transmission system planned performance during geomagnetic disturbance (GMD) events. The standard is continuing to evolve and is currently at version 4.
In Ontario, the Northeast Power Coordinating Council (NPCC) is the reliability organization responsible for developing reliability standards. NPCC Document C-15 “Procedures for Geomagnetic Disturbances Which Affect Electric Power Systems” applies. The purpose of Document C-15 is to set out the operational procedures for control area organizations (i.e. Hydro One) during GMDs. It also provides a detailed description of how geomagnetic phenomenon impact various types of electrical utility equipment.
Ontario must comply with NPCC Document C-15 for handling geomagnetic disturbances. It is the Independent Electricity System Operator (the IESO) who coordinates with equipment owner/operators such as Hydro One to manage the required response.
Space weather forecasting
Space weather conditions are forecasted by the U.S. Government Space Weather Prediction Center (SWPC–Boulder, Colorado) which is part of the National Oceanic and Atmospheric Administration (NOAA).
Natural Resources Canada (NRCAN) located in Ottawa, Ontario provides space weather forecasts which are available here.
The Solar Terrestrial Dispatch Geomagnetic Storm Mitigation System (GSMS) provides real time forecasts and alerts to all NPCC reliability coordinators as the primary method of GMD monitoring. As secondary forecasting methods, reliability coordinators receive Solar Alerts Issued by NRCAN and the Space Weather Prediction Center for two and three days ahead respectively. Secondary communication protocols are defined in NPCC Document C-15.
The takeaway
The Electricity Reliability organizations in North America have plans in place to avoid the catastrophic damage which could occur to the grid in the event of an extreme geomagnetic disturbance.
Ontario has all of the elements in place to forecast, measure and respond to GMD events to mitigate grid impact. While we have not yet experienced an extreme GMD, we are much better prepared to deal with one today than we were before 2012.
Derek
