Tis the season … for a ‘bomb cyclone’ in North America that stretches wholesale supplies of electricity (and leaves >1M customers off supply with localised network outages)

‘twas the day before Christmas (at least in Australia) and not any of my alerts were stirring with respect to the NEM operations. 

The same can’t be said for North America, with media and social media abuzz about the ‘bomb cyclone’ that’s caused havoc in North America through the same period (I’ve seen some news media report this as ‘once in a generation’ – though those sorts of superlatives are growing increasingly shaky in a climate changed world).

It’s made a number of the mainstream news media in Australia:

1)  The Australian ABC covered some of this in the video ‘Bomb cyclone brings wintery blast to United States’:


… with the news report finishing by noting ‘more than 1.5M homes are without power across the United States and Canada’.

2)  In the SMH, Heather Hollingsworth and Jill Bleed write ‘Bomb cyclone in North America wreaks havoc, causing power outages and travel chaos’.

3)  In the Australian, Alistair Dawber writes ‘Nation shivers at -45C as ‘bomb cyclone’ drops’ … and states this is ‘a once-in-40-years-event’.

4)  In the Guardian, Jon Henley, Edward Helmore and Maya Yang wrote ‘Gigantic US winter storm leaves millions without power and cancels holiday plans’, and notes that:

‘The storm, estimated to be 2,000 miles wide, has produced driving snow and plummeting temperatures, knocking out power from Texas to Maine.’

… and

‘Forecasters had said the scale of the weather pattern was nearly unprecedented in its scope, exposing than 200 million people – about 60% of the US population – to some sort of winter advisory or warning. The weather service’s map “depicts one of the greatest extents of winter weather warnings and advisories ever,” forecasters said.’

Our thoughts are with all of those affected in various ways – especially those without power through some very cold days, and the distribution crews working in deplorable conditions trying to reconnect.


(A)  Causes of power outages

With respect to the power outages, as in the many other places around the world (such as the NEM) these might be categorised into either of two broad buckets:

1)  Far more common (and likely to have contributed the lion’s share of the outages reported in stories like the above) would be localised network outages, with the most common being distribution lines down as a direct effect of the storm.

2)  Less common, but of more interest to a group of people (including us) who are more wholesale focused, would be the loss of supply attributed to stretched supply of electricity upstream in the wholesale market.


(B)  Stretched supplies in the wholesale market

So it’s been of interest to watch the pattern of ‘tight wholesale supply’ alerts through the day on social media coming from a variety of organisations …  including some of the RTOs that operate across Canada and the USA.  In the NEM the AEMO uses Lack of Reserve Market Notices – with their being three levels of three levels of LOR alert.

1)  It’s my understanding that there’s a similar approach used in these RTOs, though not exactly the same.

2)  I thought it would be useful to record some of the alerts I saw through the day…

To help provide some context to what follows, I’ve included a map of the Regional Transmission Organisations (RTOs) … which are share some of the roles of each of our TNSPs and the AEMO market operator in the NEM.


I’ve taken this image from the Wikipedia page on RTOs here, with the image attributed as ‘By BlckAssn – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=103539132 ’.

In taking a look at what’s been happening in the past 6-12 hours I came across this note by Kiera Zitelman of what NERC reported as the level of risk for ‘long-term’ reliability assessment:


… with the NERC December 2022 report ‘2022 Long-Term Reliability Assessment’ linked from that.

With respect to the RTOs above and the past ~12 hours, here’s some of what I could see:

Regional Transmission Organisation (RTO) Particular Alert we saw

Ontario’s Independent Electricity System Operator


We did not see any updates on the Twitter channels of the IESO

… but we did see:

1)  updates from Hydro One (the main TSO) such as this thread:


2)  the Ontario Energy Board did pre-emptively provide this warning;

3)  the Ontario Ministry of Energy did also pre-emptively provide this warning.

From my perspective, all of this (on brief scan) looks to be localised issues with the storm, not about stretched supplies.

New York Independent System Operator


On the NYISO twitter handle, I did not see anything specific to suggest stretched supplies.

… but I did see Jared Anderson from S&P report on power demand shooting past forecast as a result of the storm:


New England Independent System Operator


In the days leading up to the cold snap the ISO-NE reported the release of their 21-day assessment of New England’s energy supply forecasts (with that update linking to this added information from 19th December).

However there have been no Energy Alerts or Emergencies communicated via social media that I could see in a quick scan just now.

I did note on Twitter here that Meredith Angwin did comment on the relatively high use of oil-fired generation in the ISO-NE area:


Pennsylvania, New Jersey, and Maryland Interconnection


On the PJM twitter handle, there were a series of alerts issued that appear to be related to tight supply-demand balance:

1)  First notice ‘today’ (Brisbane time = UTC+10) was at 03:16AM:


… which linked to this ‘UPDATE:  Cold-Weather Alert expanded to all of PJM for Dec 24-25’.

2)  This was then followed twelve hours later with this call to conserve power:


… which linked to this News Release ’PJM asks consumers to conserve electricity’ published for this event, noting:

‘PJM is asking consumers to reduce their use of electricity, if health permits, between the hours of 4 a.m. on December 24, 2022 and 10 a.m. on December 25, 2022.’

3)  Under four hours later, PJM also shared this:


… which linked to the same Media Release and call for energy conservation.

With respect to PJM, I noted Antony Stace (from SwissRE) posted this update on LinkedIn earlier:


… including the link to the Bloomberg Article ‘Eastern US Power Grid Orders Cuts Amid System-Wide Emergency’.

Mid-Continent Independent System Operator


On the MISO twitter handle, there was even this ‘Maximum Generation Warning’ issued at almost exactly the same time as the first warning from PJM above:


… but this Maximum Generation Warning was terminated ~4 hours later, whilst they noted MISO ‘remains in Conservative Operations for the South Region’.  However that Maximum Generation Warning resurfaced ~2.5 hours later‘Due to tight conditions and unplanned generation outages’:


… and under 2 hours after that had declared a ‘Maximum Generation Emergency Event Step 2a’ with the same two causes noted:


… with further information provided in this MCS Notification about the Alert Level at NERC EEA Level 2.

(1)  Load management procedures in effect

Quickly skimming this NERC Operating Procedure for Emergency Operations, I see that EEA 2 (on p12/17) is described as follows:

‘EEA 2 — Load management procedures in effect.


(a)  The Balancing Authority is no longer able to provide its expected energy requirements and is an energy deficient Balancing Authority. 

(b)  An energy deficient Balancing Authority has implemented its Operating Plan(s) to mitigate Emergencies.

(c)  An energy deficient Balancing Authority is still able to maintain minimum Contingency Reserve requirements.’

… so sounds a little bit like our LOR2 Lack of Reserve Notices in the NEM?

(2)  Wind generation underperforming?

Approx 2.5 hours after that PJM update, I saw Kelsey Johnson ask a question about how wind performance was ~6,000MW (approx 25%) below the day-ahead forecast:


but I did not see a response.

Then ~3 hours after the prior notice, the PJM ended its Maximum Generation Emergency (again):


That’s the last update from MISO, to this point.

The tight supply-demand balance in MISO drove up prices, as Michael Caravaggio (from EPRI) noted via LinkedIn here:


In terms of the fuel mix, I saw that Tom Butz (from Minnesota Power) asked some questions via LinkedIn here:


South-West Power Pool


On the SPP  twitter handle, there have been a series of alerts:

1)  The first two published early this morning (Brisbane time),  arrived around the same time as the first alerts in PJM and MISO:


… and notes a new record for wintertime electricity consumption on 22nd December (at 47,000MW – more information here) and contains a useful graphical indicator of the progression of alert level.

2)  Then ~7 hours later the organisation declared an Energy Emergency Alert Level 1 for its entire Balancing Authority’


>> Reference to the NERC document referenced above shows that an EEA Alert Level 1 to be:

‘EEA 1 — All available generation resources in use.


(a)  The Balancing Authority is experiencing conditions where all available generation resources are committed to meet firm Load, firm transactions, and reserve commitments, and is concerned about sustaining its required Contingency Reserves. 

(b)  Non-firm wholesale energy sales (other than those that are recallable to meet reserve requirements) have been curtailed’

This alert level was ceased ~2.5 hours later:


… and that’s the last update from them at this point.

Electric Reliability Council of Texas


On the ERCOT  twitter handle, the only note today suggests that supply-demand is tight, but no EEA level alerts:

re have been a series of alerts:


… though note is made of localised (distribution level) network outages, with the helpful link to these Storm Resources from the Public Utilities Commission of Texas.

Alberta Electricity System Operator


Up north in Alberta, the AESO twitter handle contained a number of updates over the past couple of days:

Approximately 60 hours ago from writing this article (so 2 days before alerts in PJM, MISO and SPP), the AESO declared a grid alert beginning 16:24 local time on 21st December as follows:


The AESO reported system returned to normal at 18:29 local time the same day, with demand reaching an all-time hourly peak (12,193MW).


I’ve not seen any alerts in the ~2 day since (but there had been several in the days prior to that time).

California Independent System Operator


In California on the CAISO twitter handle,  I could not see any alerts specifically for that west coast grid.

Like many others (especially those directly affected) I’ll be watching with interest to see what unfolds.


PS1 – rotating Load Shedding underway in various locations

Within ~12-24 hours of posting the above, we see rotating load shedding underway in various locations.  Our thoughts are with all affected at this time.









About the Author

Paul McArdle
One of three founders of Global-Roam back in 2000, Paul has been CEO of the company since that time. As an author on WattClarity, Paul's focus has been to help make the electricity market more understandable.

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