8 ignominious Ontario electricity records

Some numbers I’ve compiled for the most recent periods of Ontario electricity consumption.

IESO weekly reports run from Wednesday to Tuesday – presumably because the market opened on Wednesday May 1st, 2002.

1 The week beginning on the 20th Wednesday of 2017, May 17-23, 2017, is the first one where the average Hourly Ontario Energy Price (HOEP), weighted to the system operator’s “Ontario Demand”, was negative.


On average, it cost money to give away electricity

I’ve highlighted recent weeks in yellow – as the records aren’t big departures from recent weeks.

2  It wasn’t a weekly record low “Ontario Demand” – which I’ve put in quotes because it is really the demand for generation from the system operator’s (IESO) generators, and one reason it’s low is increasing generation from other generators embedded within distribution networks. The lowest was 5 weeks ago; last week was 3rd lowest since the 2002 market opening, and the past 7 weeks are all in the lowest 18 demand weeks in the markets history.

Three other IESO data records from the past week (I previously noted these on Facebook):

3. the average electricity price was negative for five consecutive days (18th-22nd)

4. May now has 10 days with a negative average weighted HOEP, a record

5. 2017 now has 18 days with a negative average weighted HOEP, a record (2016 had 17 days)


Those 5 records are all ones easily found with data available on the IESO site.

6. The IESO banned negative priced exports years ago, but slightly altering IESO data to limit the HOEP to $0/MWh on exports indicates they have never been worth less than they were over the past 7 days – and the past 5 weeks are in the list of the bottom 15 export value weeks (per megawatt-hour):


7.  My estimates indicate 2017’s week 20 had by far the greatest curtailment (contracted supply paid not to generate), and again each of the past 6 weeks is in the worst 15 by this metric:


8. My estimates of hourly supply costs and consumption show the past week to be, by a significant margin, the most expensive yet for the province’s “Class B” consumer (regulated price plans are basically forecasts of Class B costs). I’ve labelled the combination of the average HOEP and the global adjustment rate the “commodity cost”. Again the past 7 weeks are in the top 13.


I’ll finish with a graphic that ends my weekly data reporting page, which may be of use to people wishing to see the drivers of the higher unit costs. In brief, excess supply can’t be accepted by the grid at any price even after dumping it on exporters, at no cost – the low HOEP causes most costs to be in the global adjustment mechanism which effectively transfers costs from larger “Class A” consumers to smaller Class B consumers.





9. I had noted Saturday May 20th was almost certainly the most expensive day ever for Class B consumers – with high wind, bright sun, big curtailment and negative pricing.


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