Avoided Blackouts! Is IESO a Great Weather Forecaster or Simply Using Historical Climate Cycles?

In case you missed it, Ontario was without almost 5,000 MW of “baseload” power over the past month and to the best of my knowledge we didn’t suffer from even one blackout, nor did we receive appeals from our local distribution company to reduce our use of electricity!

As the headline implies; IESO (Independent Electricity Supply Operator) is either a superlative weather forecaster OR they examined Ontario’s climate cycles to determine when Ontario’s electricity demand is at its lowest levels over the year?  Did they also examine when those “intermittent and unreliable” renewable energy sources such as IWT (industrial wind turbines) generate power at higher levels than they commonly do on hot summer days?

Coincidently, IWT grid connected capacity is about 4,900 MW so very close to what the nuclear capacity shut down was. The shutdown included the capacity of all of Pickering Nuclear (3,100 MW) plus a Bruce unit (830 MW) and a Darlington unit (870 MW).

Reviewing the Past Four Weeks

It has now been 28 days since Pickering Nuclear was shut down for the VBO (vacuum building outage); a process done every 12 years and requiring approximately four weeks to complete.  The Pickering units have commenced coming back online and most should be up and running by the start of next week.  The Bruce unit has also restarted and is ramping up as I write this article.

Looking back over the 28 days (October 6^th to November 2^nd) at data is an interesting exercise and demonstrates IESO chose an excellent time to allow the nuclear shutdowns as Ontario’s peak demand only occasionally was more than 16,500 MW and far below (5,000 MW) what we often see during summer months.  As examples; the 10^th highest Ontario peak demand day in 2022 (so far) was 21,379 MW at Hour 17 on July 21st and the highest was Hour 18 on July 19^th  at 22,607 MW!

The other interesting fact about IESO’s choice of when to bless the shutdown is related to when IWT mainly generate their intermittent power and in Ontario it is during the spring and fall months. A quick review of the power generated over the 28 days demonstrates their highs and lows.  As examples IWT generation on October 10^th and November 1^st was only about 10,000 MWh representing a meagre 8.5% of their capacity but on October 12^th they generated 80,000 MWh (68% of capacity) and on the 21^st they produced 82,000 MWh or 70% of their capacity. Over the entire 28 days they generated approximately 1.2 TWh (terawatt hours) which represented about 37% of their capacity and 7% higher than their average annual capacity normally in the 29/30% range.  

During those 28 days our natural gas generation sources ramped up and down as required to ensure we avoided blackouts. As just two examples; related to those very low IWT generation days, of October 10^th and November 1^st, gas plants generated 42,000 MWh and 76,000 MWh respectively!  At the same time IESO also appeared to ramp up hydro generation and that may well be the reason the US Army Corp of Engineers report, as of yesterday stated; “Lake Ontario is below its long-term November monthly average level by 7 inches”. As noted in the preceding paragraph when those IWT were only generating 8.5% of their capacity on the two days hydro delivered 97,000 MWh on October 10^th and 112,000 MWh on November 1^st!  Additionally, IESO were also importing power from Quebec, Michigan and New York and on November 2^nd IWT only generated 11,000 MWh and for 23 of those 24 hours we imported more than we exported due to Ontario peak demand reaching 16,636 MW at Hour 19!

Looking Ahead

As I pen this article my inclination is to visit IESO data and in doing so one discovers today (November 5, 2022) is apparently a great day for the IWT owners as they are reaping the benefits of lots of wind together with the fact over 2300 MW of nuclear base load power is back and generating at levels we haven’t seen for a month. With the wind blowing hard those IWT could have delivered about 65,000 MWh (including the 8,500 MW curtailed) in the first 18 hours of today, but they clearly weren’t needed. That fact reflected itself in the HOEP (hourly Ontario electricity price) market price which averaged only $6/MWh in those 18 hours.  Over those hours net exports were 33,500 MWh (51% of IWT curtailed and accepted generation) so income from the sale of those was a piddly $201K but if we assume the exports were all IWT generated we paid the operators $5.1 million so it cost us ratepayers/taxpayers $4.9 million! 

The foregoing suggests the good news evident from the nuclear baseload outage is the HOEP was generally in the $40/$50 range so by IESO scheduling the VBO for Pickering and the refurbishment for the other two units it appeared to save us ratepayers and taxpayers tens of millions of dollars over the 28 days.  Had they been scheduled for the summer or the winter when demand is higher, and IWT generation is frequently absent we would surely have had numerous blackouts or requests to stop or reduce our consumption from our local distribution company.

Conclusion

It seems obvious IESO simply looked back at their data and determined IWT have habitually generated unneeded power in the fall due to what are apparently normal repetitive climate characteristics in Ontario.