There are a number of factors in pricing, but the neglected one is consideration of the other regions Ontario is connected to (and the ones those regions are connected to, and ...)
The highest weighted average prices in Ontario thus far in 2013 are January 23, 24 and 25, and July 3rd.
The January highs correspond with a cold snap that did see the highest demand of the winter (and thus far the year) in Ontario, but Ontario had plentiful supply and net exports averaged over 2000MW an hour. [1]
Quebec didn't just have the highest demand periods of the year - Quebec is a winter peaking jurisdiction, and it experienced the highest demand periods ever.
On July 3rd three major transmission lines failed in Quebec as a result of forest fires. The impact in Ontario must have been complex as the Hourly Ontario Energy Price ended the day much higher, but Ontario also experienced it's first hours as a net importer since April.
Indications are the grid is a complex environment we don't often consider.
Endnote:
[1] Which I noted in Ontario's Electricity Exports Surge: Are they killing us? - a column with a comment section where Claude Boucher rewarded my writing with an education in trade.
Not to ignore my normal villains ...
I did also write about how poor wind forecasting was at crunchtime in January - and wind output was feeble on July 3rd too.
