Wow, Peak Demand of Electricity in Ontario on May 21st hit 20,229 MW at Hour 17

The warm/hot summer weather had an early visit to Ontario yesterday as the headline suggests and we should wonder, what power source(s) came to the rescue?

While the day started with demand in the 12/13K MW range it climbed quickly as we Ontarians enjoyed the hot summer like weather and even though demand hit that high mark of 20,229 MW no power outages seem to have appeared! 

Peak Hour Generation

At Hour 17 when Ontario demand reached the above mentioned high, nuclear provided 38.9%, Hydro 27.1% and our natural gas plants provided 26.7%! Those three sources of generation gave us a total of 18,745 MWh (92.7%) of that hour’s demand! The balance needed, came from IWT generation of 694 MWh (3.4% of demand or 14.1% of their capacity), net imports from Quebec of 1,189 MWh and solar at that hour provided 132 MWh.

IESO Forecasting

The very interesting IESO data from May 21^st was in respect to their forecast of wind generation versus what was actually accepted!  It leads one to suspect either the forecasts were way off or the wind itself was blowing on and off causing the differences. In examining the IESO data it is noteworthy they forecast 750 MWh that didn’t make it for the first three hours of the day and for the last 3 hours they accepted 1,229 MWh they had failed to forecast would be generated. It appears however, neither of those missed forecasts had any affect on the market prices.

Hydro Quebec’s Role

It is also worth noting Hydro-Quebec has been a major importer of Ontario’s surplus electricity generation purchasing around 1,200 MWh of Ontario’s generation on a fairly consistent basis since the start of the late fall in 2023. Presumably this helps them to save some hydro generation for high demand periods when they supply U.S. purchasers under long term contracts. Yesterday they were purchasing surplus power from Ontario for the first eight hours but were actually supplying power to Ontario from hour 9 to hour 22!

Without Natural Gas

Now, let us Ontarians contemplate how we would have been yesterday without natural gas generation? It is incredible that both the OCAA (Ontario Clean Air Alliance) and Environmental Defence have both pushed for closure of those natural gas plants as they emit those greenhouse gases, they and other eco-warrior groups believe are causing “global warming”. What that would have meant yesterday was; no air conditioning, no cooking on your natural gas stove and no charging of that EV the government helped you purchase with a grant unless your roof was loaded with solar panels and your garage was full of batteries that were fully charged.

Conclusion

It should seem obvious to our politicians, our energy regulator (OEB) and IESO that without our natural gas plants generation of 90,850 MWh for the day we would have needed an incredible amount of BESS (battery energy storage systems) to replace them. A BESS unit has the reputed ability to generate their rated capacity for four hours meaning we would have needed 23,000 MW of capacity had they been fully charged to deliver the power when needed. Currently IESO have contracted about 2,000 MW of BESS suggesting without the other 18,000 MW capacity we definitely would have experienced blackouts throughout the province without natural gas generation!

Hmm, we should wonder, what would those BESS units cost us ratepayers?

Stay tuned as you will find out in my next post and the needs may well exceed the 23,000 MW capacity for just the one day!