Wind Turbines Less Productive than Expected

Having looked at the ability of Ontario's system operator to forecast near-term wind productivity in my previous post, I put some data together to show a similar inability to forecast "Capability at Winter Peak".

The IESO presents the anticipated "capability" during peak demand in it's 18-Month Outlooks, as part of it's resource adequacy assessment: for this winter it noted 507MW (of 1511MW capacity), while their summer assessment noted a forecast capability of 202MW (of 1511)

The data shows this is wrong.


I've looked at the highest 5 daily demand hours, for both winter and summer, since shortly after the data begins on wind output in Ontario.  This year, only once did wind perform above the IESO's predicted capability, while during the highest peak the production was 1/5th of the stated winter peak capability.

The summer figures can be seen in this Google spreadsheet.

Wind turbines produce at roughly half the efficiency in the hottest, and in Ontario highest demand months, as they do in winter's cold - but the turbines are still frequently unproductive in the winter, including during peak demand hours.