The Toronto Sun had an editorial this morning on “Clean electricity’s dirty secret”. It must have generated a buzz about the negative pricing, and dumping of hydro supply, because it was followed this afternoon with an article, by Antonella Artuso, which told us of the Premier’s responses to reporters’ questions regarding exporting power cheaply; “McGuinty said he appreciates that many Ontarians struggle with his energy program — including the requirement that municipalities take wind turbines — but the goal is to bring green manufacturing jobs to the province and supply greenhouse gas-free electricity.”
If that is the goal, perhaps our Premier isn't getting great information from his underlings regarding his programs success. I've heard he's a real detail guy, so I've assembled some details to help out.
I recently started looking at hourly production data from the IESO, and bringing it alongside some longer term data also from the IESO. I've been surprised to discover the largest hours of net exports are quite deliberate - and the production figures are enormous. Three days containing some of the largest net exports since IESO tracking began were in 2011 between January 31st - February 2nd. During these 3 days Ontario demand was high, peaking at 22045MW at 7pm on the 31st. That was near the anticipated high for the month in IESO forecasts. Production at that time was 25776MW – the second highest production, since the IESO records begin in 2002, during the 2410th highest demand hour (demand hasn’t been above 25776MW since 2006).
This graph shows the supply during this 3 day period. The wind is not particularly notable. The natural gas output is. The light blue line is Ontario Demand, so supply above that line represents exports.
This has been a frequent occurrence in Ontario during the last winter. 19 of the top 20 highest net exporting hours, since 2002, have occurred since December 16th, 2010, and only 2 of those hours were due to exceptionally low demand (on New Years’ Day).
The plan, requiring 3500MW of generation from burning natural gas for export at around 4 cents/kWh, isn't likely a plan to supply GHG-free electricity. I’d say that’s a plan to hide the reckless procurement of unnecessary natural gas supply behind a screen of wind.
In the shoulder seasons, that isn’t to say wind can’t be a problem. In stark contrast to the oversupply during the peak demand hours of the above days, April 11th is an example of huge oversupply at night. It is worse. The winter’s deliberate excess is sold at 3-4 cents/kWh, which is likely around, or maybe over, the incremental cost of its production (the nature of the natural gas contracts is speculated upon – because they are private, but indications are we pay the largest plants a flat rate for the capacity - for production we pay only for the fuel). In the spring, we run into situations, such as we encountered overnight on both the 10th and the 11th of April, where we simply have too much supply even without any intermediate or peaking production, and the need to dump power causes the downward spike in the price (the red line measured on the right axis):