Renewables advocates have been claiming that solar and wind generation are now the least costly form of generation, and therefore, should replace all fossil fuel generation as quickly as possible.  Is this correct?  A number of energy analysts have reminded us that weather-dependent wind and solar generation are necessarily intermittent, requiring costly backup when the wind isn’t blowing and the sun isn’t shining.  However, few commentators have examined actual operating experience in as much detail as Parker Gallant, a retired international banker.  A large part of this blog post is based on Mr. Gallant’s analysis, for which I thank him. 

Using Ontario statistics, he has demonstrated in recent blog posts (such as this one) that these forms of generation, and particularly wind turbines, are extremely costly to both consumers and taxpayers, often inconveniently providing high output when not needed and providing next to none when needed.  This results in:

• paying these generators high prices even when their energy it isn’t needed;
• exporting surplus generation to neighbouring US states or Canadian provinces at low or zero prices; and
• importing electricity from neighbours at higher prices at peak times, when wind and solar often generate almost nothing.

Ontario’s Independent Electricity System Operator (IESO), which operates the electricity grid, provides daily statistics, for each hour of the day, e.g., on:

• how much electricity the province generated to meet hourly demand;
• by what methods it was generated;
• how much was imported or exported;
• at what prices. 

This permits us to examine the efficiency and cost to Ontario electricity customers and taxpayers of each method of generation, including wind and solar.  Although all Canadian provinces and territories will have different mixes of generation methods, all are committed to increasing the percent of wind and solar generation in their generation mix.  This is to try to reduce their CO2 emissions to net zero.  Therefore, the Ontario data can provide a useful base for examining the costs and benefits of renewables elsewhere, with necessary adjustments for the generation mix and the output of renewables in different geographic areas.

November 28, 2022, a Typical Late Fall Day in Ontario

As Ontario approaches its winter season its peak electricity demand will often be over 20,000 megawatts (MW).  On November 28th, 2022, Ontario’s peak demand for electricity was 19,360 MW at Hour 18 (the hour ending at 6 PM). But wind turbines generated almost nothing at that hour. At Hour 18, when the wind wasn’t blowing, wind turbines were able to deliver only 1% (200 MW) of that peak demand.  That is only 4% of the wind turbines’ total rated capacity!  (The rated capacity is the theoretical maximum output if the wind was blowing hard.)

On the other hand, during the early morning hours from 1 AM to 7 AM, when demand was as low as 12,990 MW, they generated 13,524 MW, more than was needed, on top of all the other generation that was then available. 

For the remaining 17 hours of the day, as demand was rising to the peak, wind turbines generated only 6,862 MW, an average of only 8.2% of their rated capacity.  As we can see, they generated twice as much electricity at the off-peak hours when it wasn’t needed and half as much when it was, as the system approached peak.