Alberta’s Renewable Energy Conundrum in Charts and Numbers – Why Capacity Factors Matter

Over the holidays I have read a lot of commentary on Alberta’s energy future. I keep seeing individuals demanding that Alberta concentrate on wind and solar for its energy future. The people making these statements are mostly activists and journalists, rather than policy types. As a numbers person, I feel it is incumbent on me to inject some actual numbers into this discussion. This blog post will explain why solar and wind, alone, can’t address Alberta’s energy needs, but rather will serve as part of a larger energy mix.

To understand this topic let’s start with some simple statistics. In 2018, Alberta’s average internal load was 9714 megawatts (MW), its winter peak demand was 11,205 MW and its summer peak demand was 11,169 MW. As for the provinces generating capacity according to the Alberta Electric System Operator on January 1, 2019 their internal capacity was:

Capacity (MW)

For those wondering about the “other” it is mostly biomass with minimal solar. So currently 81% of Alberta’s capacity is made up by the combustion of fossil fuels.

Now for a quick proviso. These demand numbers are current and do not reflect any significant implementation of policies to reduce Alberta’s reliance on fossil fuels for other energy uses. If Alberta chooses to further encourage the use of electric vehicles and reduce the reliance on natural gas for heating and hot water then these demand numbers will necessarily increase substantially.

Another thing to understand about Alberta is that its electricity system is severely limited with respect to import/export capacity. It has interties in three directions: to BC, Montana and Saskatchewan. But these interties are severely limited. As described in a report from the University of Victoria:

Currently, BC and Alberta share a single transmission connection (called an intertie) with a design capacity of 1200 MW. However, due to constraints of the Alberta electricity grid, this intertie is limited to a maximum of 780 MW.

Meanwhile the intertie from from Montana is 300 MW and from Saskatchewan is only 153 MW. That means that at a maximum, Alberta can import 1250 MW. This represents less than 12% of the winter peak load (why I use winter peak will be come clear later in this article).

So here is the renewables challenge: Alberta needs to figure out how to generate nearly 11,000 MW of electricity using only renewables. Well Alberta’s geography doesn’t help it. It has a strictly limited hydro capacity, most of which has already been exploited. It has no access to tidal, wave or offshore wind which leaves: solar, wind and geothermal as its non-nuclear choices.

A further thing to understand about renewable energy generation: it is highly intermittent. There will be days when the wind blows and others when it won’t. The way to address this intermittency is two-fold: storage and redundancy. Storage is easy to understand. Energy can be stored in batteries or in facilities that rely on momentum, compression or gravity. Redundancy is the bigger consideration.

There are two critical features of redundancy: geographic and physical. With respect to physical redundancy you can overbuild solar facilities so they produce excess energy when the sun is shining to make up for the hours when the sun isn’t shining. Geographic redundancy involves building over a variety of areas with the assumption that the wind will always be blowing somewhere and it is always close to midday someplace on the planet. Unfortunately for Alberta geographic redundancy is not on their side. Consider this solar insolation map of Alberta:

As you can see, the only area where utility-grade solar makes sense is a limited geographic area south of Calgary. Unfortunately this essentially eliminates Alberta’s ability to build any significant geographic redundancy into their solar facilities.

Next let’s consider wind. Here is a map of wind capacity factors for Alberta:

Alberta has more geographic diversity for wind but most of the good spots are either in the mountains or in the windy south of the province. For cost-effective facilities it is hard to get the diversity necessary to provide good redundancy.

What does this mean from a practical perspective? Well let’s take a look at the performance of solar and wind facilities in Alberta from this past December. Here is a graph of the Alberta solar generation (next three graphs are courtesy of Reliable AB Energy)

That top line is the nameplate capacity of the facilities while the actual generation is the small peaks. As is evident from the graph, solar production this December was abysmal. As for annual numbers, the National Energy Board has calculated capacity for areas where Alberta has potential utility-scale solar and indicates the capacity factors range from 13% in Collin Lake to 18% at Peigan Timber. These capacity numbers are incredibly problematic. What they mean is that for Collin Lake if you wanted to generate 1000 MW of power you would need to build 7.7 – 1000 MW facilities. These would generate a lot of power during their good days and virtually none on their bad days.

Wind is better but still not ideal.

There are days when the wind does approach its capacity while others, where no power is generated. Overall, in 2018 the wind in Alberta operated at 32% of capacity so once again wind would only work if it was massively overbuilt.

How about the two together? On December 19th, at midday, wind and solar would have done a pretty reasonable job, but for much of December 13th Alberta essentially no electricity from its solar and wind facilities. For a more comprehensive picture lets look at February 2019 (one of the coldest Februaries on record.)

For much of the month, wind and solar capacity were near zero. No reasonable combination of wind, solar, storage and imports would have allowed Alberta to function during that month.

What this data shows is that if Alberta is going to forge a fossil fuel-free path to energy independence, wind, water and sun will simply not do the job in Alberta.

Alberta needs to look at regionally-appropriate energy alternatives. It needs to modernize its transmission system and massively upgrade its system of inter-provincial interties. While Alberta couldn’t reasonably design and build energy storage facilities capable of meeting its demand it doesn’t have to, because British Columbia has already done so through its large-reservoir hydro network.

If British Columbia and Alberta worked together they could create a system that took advantage of Alberta’s abundant wind and reasonable solar resources along with BC’s hydro and wind. The problem with BC is that it needs its hydro to operate, but if it could import from Alberta when the wind was blowing, then it could save that water behind its dams for when the wind was not blowing to sell back to Alberta.

Additionally, Alberta needs to come up with dispatcheable, fossil fuel-free power in the form of geothermal and/or nuclear power plants. I know the latter will be divisive but the alternative (letting Albertans freeze in the dark) would be more divisive. Any activist who is serious about breaking Alberta’s fossil fuel addiction needs to be working towards upgrading Alberta’s transmission system; improving its inter-provincial interties; and developing geothermal and nuclear alternatives to fossil fuels. Water, wind and sun alone will not do the job in Alberta no matter what the activists tell you.

This entry was posted in Environmentalism and Ecomodernism, Fossil Fuel Free Future, Renewable Energy, Uncategorized. Bookmark the permalink.

22 Responses to Alberta’s Renewable Energy Conundrum in Charts and Numbers – Why Capacity Factors Matter

  1. Jeremy Campbell says:

    Thank you for another excellent article. 25 years ago I would have shot myself in the foot if I said I thought we needed nuclear energy. I am very pro-modern nuclear energy now. When was the last time you heard somebody say,” I won’t go to France because they have 59 nuclear reactors!? “

    Liked by 2 people

  2. davidwalters66 says:

    What is clear is that 2 x 1000MW nuclear plants would solve this problem of congestion and load for the Province.

    Liked by 1 person

  3. Chris Lashmar says:

    Interesting article. I have a few comments and questions.

    Re: “As you can see, the only area where utility-grade solar makes sense is a limited geographic area south of Calgary. ” – I would, instead, draw the conclusion from this chart that the cost of solar needs to be about 4%-8% cheaper to be cost effective in the orange and yellow regions than it does in the red region. Do you have other information that makes it obvious that the orange areas will not be suitable for utility scale solar in the next 10-20 years?

    Re: “It has a strictly limited hydro capacity, most of which has already been exploited.” – Can you provide a source for this? According to this ( Alberta has about 900 MW of installed capacity of a technical potential 11,800 MW. I do not know how difficult it would be to develop that remaining potential.

    Re: “These capacity numbers are incredibly problematic. What they mean is that for Collin Lake if you wanted to generate 1000 MW of power you would need to build 7.7 – 1000 MW facilities. These would generate a lot of power during their good days and virtually none on their bad days.” – I think the capacity factors you cite are based on an annual period. While I understand there is a significant problem with solar and wind power not being available to dispatch as needed, and that their generation profiles cannot be relied upon to match the load profile, I don’t see why the capacity numbers are “incredibly problematic” on their own. Maybe as a proxy for the mismatch between load and generation profiles? If we want to consider energy storage solutions to complement wind and solar, then perhaps it is useful to determine capacity factors for each month or season and compare the capacity factor changes to the expected load changes.

    In a 2017 proposal for a capacity market, AESO calculates the capacity factor using “the 250 tightest supply cushion hours per year for the past five years” rather than the entire year. ( I think this would make it tough for solar to compete in this market on its own. But the proposal also allows for aggregated assets so that might provide a few more options. Regardless, on July 24, 2019 the AB government announced AB would not transition to a capacity market. I thought it still worth drawing attention to this document and method of analyzing capacity.

    Re: “Percentage of Capacity by Generation Source” chart. As mentioned in one of my replies to you on Twitter, the graph may have some data issues for the solar capacity from Feb 13-28. I understand your graph uses @ReliableAB data which gets its data from AESO. As far as I can tell, there is only one solar plant (Brooks 15 MW) tracked there and microgeneration (appx 40 MW as of February 2019) is not tracked. (See for list of assets tracked)

    According to the weather data from, there was a complete gap in weather data from Feb 13-22. After that, a normal solar radiation profile resumes. So the zero power production from Feb 13-28 might represent a production problem at the Brooks plant, or it might be a data collection issue. It is weird that it coincides for a period with weather data issues. I don’t think it represents a likely scenario whereby there is zero solar power production for two weeks if we scaled up solar beyond one plant. However, your main point still remains valid that the capacity factor during winter is much lower than spring to fall. You might find this app very interesting to see the Brooks Solar production for any period.



    • paulrenaud says:

      Chris is spot on, if you look at other solar generation locations in Canada you will see plenty of facilities successfully operating in the orange zone.

      As for wind, it is a truism that the higher the tower, the more wind it catches. The wind map does not assess the potential for wind on the mountains of Alberta.

      Geothermal is a significant unexplored opportunity for Alberta. The Geothermal association estimates that 10% of oil wells have bottom temperatures exploitable by geothermal, including many abandoned wells. These are easily exploited and means that additional facilities are also possible.

      Finally, the priority for the world is eliminating the use of coal for electrical generation. That is only a 6MW goal for AB. Once this is accomplished, improved storage solutions may be available given the significant amount of research being done on this right now. Any discussion of energy transition cannot realistically omit timelines and the potential for change in assumptions over time.

      So looking further down the road, nuclear fusion (not fission) is likely to be commercialized within a decade along with class 4 breeder reactors that avoid ,(in the case of fusion) or consume radioactive waste (in the case of breeder reactors).


      • Chester Draws says:

        Once this is accomplished, improved storage solutions may be available given the significant amount of research being done on this right now.

        So looking further down the road, nuclear fusion (not fission) is likely to be commercialized within a decade

        How about we use a technology that we know works — nuclear fission — rather than pretend some miracle is going to happen.

        Fusion has been promising it is just around the corner for fifty years now. At what point do people slowly begin to realise that it probably will never happen?

        Regarding the “improved storage solutions”, I always think: if wishes were horses beggars would ride.

        We have over the years learned about a few storage solutions that are relatively concentrated and relatively safe — the best is, um, fossil fuels. That’s why we use them.

        We have others that are already commercially viable — we could electrolyse water to get hydrogen. But that’s quite dangerous. We can store water in dams, but that’s massively inefficient.

        We’ve been trying to come up with storage solutions for a long time. The easy picking is already gone. The remainder is difficult, or we would have worked it out a long time ago.


    • Rob Harlan says:

      The solar insolation map shown in the article is overly dramatic and lacking in perspective. A wider frame of reference would reveal that the variance in production from south to north is not that significant. From the perspective of Germany (848kWh/kW/yr.), Japan (885kWh/kW/yr.) or England (728kWh/kW/yr.) a project at Alberta’s norther border (1200kWh/kW/yr.) looks quite do-able.


  4. DMacKenzie says:

    Blair, you made the common inference that if you have 15% capacity factor that “maybe” overbuilding by a factor of 7 might accomplish something, which I know you didn’t mean literally but could be taken that way by some. But fact is if the wind isn’t blowing, you can be overbuilt by a factor of 1000 and still have no electricity. When the the wind isn’t blowing the economics favour 100% standby natural gas generation. Then the next logical step, unfortunately for eco warriors is “if you have to have 100% NG generation capacity, why bother with paying for weather dependent wind and solar to start with?” Other than concern about CO2 emissions, which are a lot lower for NG generation anyway, plus Canada, overall, has such large hydro and nuclear generation in the East and BC, that our CO2 footprint for electricity generation is pretty low.

    Liked by 1 person

    • Ikemeister says:

      “if you have to have 100% NG generation capacity, why bother with paying for weather dependent wind and solar to start with?”

      Because of the fuel savings.

      “… the wind plants and the solar plants are gas plants” – famously spoken by Robert F. Kennedy Jr..


      • Chris Morris says:

        It isn’t as simple as that. The capital cost of the wind and solar, plus the transmission system to support it, may well have a capital and operating cost (this is significant for wind units) greater than the cost of GT fuel. Numbers are tossed around with gay abandon by both sides of the argument, but it does seem the capital cost is significantly higher than the fuel, especially where gas can be supplied from fracced wells


      • Neodymigo says:

        Well, the mortgage payments on the real estate for solar is less than the cost of the natural gas for turbines, so you might as well consider natural gas to be free on that basis, same as sunshine….


  5. davidwalters66 says:

    We call this the “cost of intermittency”. The cost to build, maintain and fuel GTs when the sun isn’t shining and the wind isn’t blowing. It’s never calculated into the costs of wind and solar. One can also translate this into the “CARBON cost of intermittency”.


    • paulrenaud says:

      One of the aspects overlooked in your analysis is the potential for onsite solar generation. The huge advantage of solar is that it doesn’t have to be provided by massive power plants and can be generated onsite without the need for transmission facilities. When you factor in the fact that solar generates power during the day when demand is highest, this cannot be ignored out of hand.

      Using Ontario’s IESO data and forecasts, roughly 10% of Ontario’s power need is met by onsite solutions today (much of which is orange zone generation). This could be higher if the recent Ontario gov had not been so shortsighted to discourage onsite solar via Microfit cancellation.

      Instead of starting with a premise that renewables are infeasible, your analysis would be better served by a more balanced look at what is possible and proved elsewhere.


      • Blair says:

        Except demand is not highest during the day, rather every analysis (look for duck curve) shows demand is greatest in the early evening. Daytime demand is relatively low with peaks before work and the big peak (duck head) in the early evening (when solar provides no help)


      • davidwalters66 says:

        What is the cost for all the backup for solar? Alberta’s solar time is around 5 hours mid day. Zero during spring and winter storms. In most places peak usage is early evening. In the winter time that 5 hours is reduced a few more hours. Outside that 5 hours or so, what is to produce the generation? It’s hugely bad investment from either an general energy perspective or one that would that would reduce carbon.


  6. Chris Morris says:

    Blair – you are right and that duck curve is a very big cost. Having to ramp GTs up in a hurry shortens their life, making maintenance costs a lot higher. Running them at part load is also a lot less efficient than full load. All adds to the cost of operation which is the cost of intermittency. That is why the power bills go up.


  7. Ron Myers says:

    Alberta does not have a fossil fuel addiction. Like every other jurisdiction in Canada and around the world it has an energy use addiction. Energy to heat homes, heat water, cook food, power transportation, etc. The same energy that drives our economy and standard of living again like everywhere else in the world.
    The wind and solar analysis is informative and finally the author stated that power generation and use should not be restricted by artificial provincial boundaries. We need to rationalize power generation by utilizing all forms of generation and transmitting it as required. However there is no free lunch – hydro power floods valleys and destroys habitat, nuclear power generation has its own perceived and real warts and storage batteries have their own significant footprint. Unless we are all ready to move to the cave energy needs will continue to grow and we need to collectively rationalize its use and generation.


  8. G. Barry Stewart says:

    Conservation is the first thing that should be looked at.

    If you can save 10, 20, or 30% of the load by stringent new building codes and retrofitting older, less efficient infrastructure: you avoid having to build new generating capacity. If it helps hold off new power generation for even a few years, that allows time for improved generating technology to come along.

    You’d think a “Conservative” party should be all about conserving…


  9. AlbertahPowah says:

    Alberta has a massive potential for hydroelectric and geothermal development.
    “While many of the province’s best hydro locations have already been developed, the Canadian Hydro Association estimates that Alberta still has more than 11,500 MW of remaining economic hydro potential including both reservoir and run-of-the-river projects.”

    “120 GW of potential demonstrated geothermal power (Canadian Wind Energy Association,
    2013; Alberta Utilities Commission, 2010; Canadian Geothermal Energy Association, 2013)” Page 4 of

    Bruce Nuclear Generating Station is 6,430 MW. If AB built ONE station that size, we could meet approximately 64.3% of our province’s electricity needs (average load at a given time is 10 GW). Of course, AB could build a bigger power plant or one of that size and a couple smaller ones. Or, AB could combine nuclear with hydroelectric, geothermal (crucial), wind, and solar.


  10. Pingback: Debunking common anti-nuclear talking points Part 1 – Nuclear takes too long to build | A Chemist in Langley

  11. Chris Popoff says:

    I cannot wait to see nuclear in Alberta. The SMR roll out plan could not be more exciting as it has potential to address the decarbonization of Alberta’s other much larger grid – thermal energy demand. Cannot wait to hear more about why Alberta signed onto this and how they’re going to participate.


  12. Chris Popoff says:

    More important reading, Blair. Would love to hear your thoughts on this work.


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