Capacity Factor of Ontario Wind Energy Generating Facilities

Capacity Factor (Efficiency) Given as a Percentage of the Nameplate Power Output: July 2009 – June 2010

Month Amar-anth Kings-bridge Port Alma Port Burwell Prince Ripley Under-wood Wolfe Island Overall
Name-plate (MW) 200 40 101 99 189 76 182 198 1085
Jul-09 16 11 18 14 15 12 14 14 14
Aug-09 18 21 21 17 19 21 21 16 19
Sep-09 16 18 21 17 16 17 16 20 18
Oct-09 25 35 39 34 29 30 33 32 31
Nov-09 23 32 35 25 34 29 28 22 27
Dec-09 31 43 41 36 29 37 39 35 35
Jan-10 27 39 48 36 28 39 38 27 33
Feb-10 24 25 31 23 21 25 24 23 24
Mar-10 28 27 37 26 26 28 26 37 29
Apr-10 34 38 47 30 31 36 34 29 33
May-10 24 24 37 27 25 24 22 20 25
June-10 19 18 27 18 19 18 18 17 19
Annual Average 24 28 34 25 24 26 26 24 26

The table shows the monthly capacity factor for the Ontario wind farms for the year July 2009 to June 2010.  The capacity factor is the actual power output divided by the nameplate power; it is given as a percentage.  The nameplate for each wind farm is given in the second row.  As an example, consider the July-09 entry for Amaranth:  The average hourly output for that month was 32 MW.  Dividing by the nameplate power of 200 MW, we get 16%.  The row labeled Annual Average is the 12-month average. 

The bottom line is that the Ontario wind energy system produced an average power output of 280 MW, about one third of one coal plant.  This is enough to power the needs of 200,000 homes.  This number is based upon Hydro One’s figures of 850 kWh per month for an Ontario home without electric heat and 1700 kWh for a home with electric heat.  I have assumed an average of 1000 kWh per month for an average home.  This 280 MW output is less than 1% of the electrical energy capacity available to Ontario (31.5 GW on December 30th, 2009 at noon) and about 1.5% of the typical demand (19 GW on December 30th, 2009 at noon, including 2 GW for export).

On the same date, December 30th  2009, that the above numbers for Ontario’s power generating capacity and power demand were recorded, the fraction of the Ontario energy supply that was “green” (nuclear, hydroelectric and wind) was 80%.  The European protestors at Copenhagen who awarded Canada the “fossil of the year” award can only dream about such a high fraction of ”green” electrical energy in their home countries!  Manitoba and Quebec have “green” electrical energy ratios similarly high because of their abundance of hydroelectricity.

It is instructive to consider the variation of the annual average capacity factor of the Ontario wind generating plants from year to year.  This can only be done for the complete years of operation of the plants.  Amaranth was brought on line in 2006 and enlarged during the 2008 – 2009 year.  It is clear from the capacity factors of plants operating back to 2006 that 2009 – 2010 was a poor year across Ontario.  It is not clear if this is a trend or a fluctuation.  If a trend, the reason could be wear and tear and down time for maintenance.  If a fluctuation, then the Ontario system could expect an annual average capacity factor close to 30%.

Annual Average Capacity Factor (Efficiency) Given as a Percentage of the Nameplate Power Output.

YearJuly to June Amaranth 1 Amaranth 1&2 Kings bridge Port Alma Port Burwell  Prince Ripley Under wood Wolfe Island 
2006 – 2007 30   33   29        
2007 – 2008 29   35   27 29      
2008 – 2009     33   28 27 33    
2009 – 2010   24 28 34 25 24 26 26 24


John Harrison – July 2010.

14 thoughts on “Capacity Factor of Ontario Wind Energy Generating Facilities

  1. Looks like OPA will have to dramatically raise the subsidies that they give to Wind Energy Companies and raise our energy rates to support the FAKE Green Energy Act….

  2. Amazing isn’t it?

    Everybody who analyzes these numbers ends up in the same place.

    Wind Turbines are not worth the ground they are sited on.

    Is it just the money? Is it all about the subsidies?


    Respectfully: The Green Energy Act is not FAKE it is REAL that is the problem.

  3. Since these figures are readily available to anyone, why is the media so silent on the implications?
    This is abysmal performance for millions of dollars invested, and most of the turbines are relatively new. What will the efficiency be once they get older?

  4. “The average capacity value of the wind resource in Ontario during the
    summer (peak load) months is approximately 17%. The capacity value ranges
    from 38% to 42% during the winter months (November to February) and from
    16% to 19% during the summer months (June to August). Since 87% of the
    hits (periods within 10% of the load peak) occur during the summer months,
    the overall yearly capacity value is expected to be heavily weighted toward
    the summer. The overall yearly capacity value is approximately 20% for all
    wind penetration scenarios. In other words, 10,000 MW of installed nameplate
    wind capacity is equivalent to approximately 2,000 MW of firm generation

    Page 7 of this 2006 report to the Provincial Government:

  5. David, that characteristic does follow the demand curve. This shows in my figures as the MID peak being lower (mornings being MID PEAK periods).
    But we didn’t need stats to know the wind comes up in the afternoon here.

    I suggest it is unhelpful to invent more problems with wind generation — it isn’t healthy, it doesn’t reduce GHG emissions, or emissions of other pollutants, much, if anything, and it is a source of generation which is both unrelated to demand, and unrelated to reliability.

    Shouldn’t that be enough to discourage it?

    There is another interesting thing about wind stats for the period in this article. The wind was below expected productivity from Sept – March. If you look at figures 7.2.1 and 7.2.2 in the IESO 18 month outlook, there appears to be a stong correlation between reduced wind and reduced precipitation.
    If my math is correct, last year’s hydro output (38.1 TWh) averaged 4349 MW each hour. The max the past couple of days is a little over 4100MW. If the wind disappears for an extended period, the hydro likely drops too.

  6. Why is Port Alma so high? From what I understand they are 4%higher than what the industry expects from Ontario.
    I think it’s the proximity to Detroit so they sell it across the border.

  7. Sam:

    Some sites are going to better than average, and, some sites will be worse.

    If you mean “What is it about the geography that contributes to the better performance?” I don’t know.

    Perhaps looking at google maps satellite or TOPO view could give some hints. However, you would have to couple that with local knowledge of wind patterns and weather system movements. Put another way, maybe they got lucky!

  8. Sam, it could be the site selection … but it is worth noting that Port Alma is owned by a company that does genuinely seems to be attempting to be a green energy company – Kruger Energy
    Most aren’t.

    TransAlta has 398 MW (Wolfe and Amaranth), Epcor, 40 (Kingsbridge), Enbridge 181.5 (Underwood), and Suncor owns part of 76 (Ripley South).
    They make a little off of the wind, but it isn’t their real business. The wind is a hedge protecting future coal operations from potential cap-and-trade schemes. For the natural gas guys its a beautiful way to bump nuclear.

  9. FYI…maybe be relative, may be not…may be this belongs on another post on this website.

    The transformer which blew in Etobicoke on Monday caused hundreds of diesel generators across the city to kick in releasing diesel fumes into the atmosphere. At the TelcoHotel for example (the main telephone building for our company and the likes of others such as Bell Canada, Rogers, Telus, AT&T, Verizon and an host of others), the power went out and the generators kicked in. Each generator is the size of a full sized van and there are at least a dozen there, all running. When the power goes out hotels and hospitals run on diesel too.

    The writing is on the wall. With aging and failing infrastructure, this will occur more and more frequently as time goes on.

    What was the point of the McGuinty/Smitherman plan? Oh, right, reduce our GHG output. How did that work for them on Monday? The smell of diesel out back of the Telco hotel was sickening. My guess is, it wasn’t environmentally (green) friendly.

    Ontario needs to quit wasting our $$$$ with their ideological wind generators, build the grid properly and get back to producing real electricty.

  10. Well said AAW!
    “Ontario needs to quit wasting our $$$$ with their ideological wind generators, build the grid properly and get back to producing real electricty.”
    This government fails at governing.

  11. This is great data!

    What was the source for these July – June Capacity Factor numbers? Can anybody forward me a link to where i can get more data like this?

    I’d like to do an analysis of wind energy CF in Ontario. Thanks.

  12. P.L., you can also get the raw hourly data for output directly from the ieso site – both for all wind and by wind farm in general:

    The links for the .csv files are on the right and are updated weekly.

    The trickier part for the initial periods of a wind farm’s existence is the start date- the one .csv file has output data for farms before they fully come online.
    I’d probably throw out the initial months of data for each grouping of IWTs if I went further with it – but Tom Adams data is good as is David Robinson’s Watts With the Wind

  13. Thanks a lot for the links. The sygration website is great. As is the ieso site.

    I’ll look into Robinson’s report also.


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