I received an e-mail today from a concerned reader wondering at the lack of new posts.
I wish I'd been simply doing other things, but I have been doing the back-end data collection to further my arguments regarding Ontario's electricity system challenges/follies.
I noted a study that came out in the UK recently; “The Impact of Import Dependency and Wind Generation on UK Gas Demand and Security of Supply to 2025,” from The Oxford Institute for Energy Studies.
Chapter 6 of that study, "Wind Intermittency," was not only informative, it included a number of helpful graphs that I felt I would be capable of assembling, with Ontario data, to communicate a similar message in the context of Ontario.
The data base for much of the forecasting work is now built. I shared generation capacity figures in an earlier article showing why wind cannot replace our coal capacity, specifically during July. My assumptions, added to my understanding of the supply mix directive handed down to the Ontario Power Authority (OPA), to be used in producing an Integrated Power System Plan (IPSP), results in a supply mix that looks like this:

Looking at the past, and planned future, wind production, it is easy to see why. I developed the next graph (inspired by the Figure 36 on page 63 of the document from Oxford). For the forecasting, I used the most recent 365 days available, along with the annual wind generation figures I've illustrated in the last graph. Averages were not used despite wind data being available from 2006 on, because it is average for wind to disappear one day and reappear again in varying strengths. The IWT's functioning over the past 365 days operate from the Sault Ste. Marie area to Wolfe Island. The geographic disbursement doesn't help much.
It is apparent that wind will deliver over 6000MW within days of delivering less than 400MW. I'd conclude it is always extra supply capacity within a supply mix ready to meet demand. There is an argument made that wind output is only $X/MWh, on a levelized unit energy cost (LUEC) basis. The specific amount doesn't matter because it is, by itself, irrelevant. The relevant figure is what it costs the system as a whole.
In a future post I'll examine the supply mix and estimate the costs associated with producing more electricity than Ontario consumes.
Notes:
The graphs shown here are from data held in a spreadsheet here. Also in that location is a zip folder containing an MS Access 2007 database file containing, without any guarantee of accuracy, data I've collected from hourly reporting, and/or freely available data off of the IESO website.