Ontario electricity carbon spikes past 100 grams per kilowatt-hour: the environmental cost of the Perfect Storm of 2009

On days like today, when it is below minus 20 °C across most of Ontario, nobody cares about the environmental cost of staying warm. You gotta do what you gotta do. When I get into my gasoline-powered car and turn the key, I, just like the next guy, impatiently wait for the first signs that the ice-cold engine is warming up. Well, like I said my car is gasoline-powered. That means it produces two major things:

  1. Carbon dioxide (CO2), the principal man-made greenhouse gas. Every litre of gasoline that my car’s engine burns combines with oxygen in the air to produce 2.3 kilograms of CO2.
  2. Heat. When gasoline combines with oxygen to make CO2, it also releases a significant amount of heat. The heat increases the pressure in my engine’s cylinders and drives the pistons in those cylinders. The resulting mechanical power is what makes my car move.

On minus-20 days like today, the fact that each litre of gasoline, when burned, turns into 2.3 kilograms of CO2, is of secondary—perhaps even tertiary—concern. What I really only care about is the heat that is produced in the transformation of each litre of gasoline into 2.3 kilograms of CO2. That heat is what makes me relatively comfortable and capable of functioning on minus-20 days like today.

There is nothing, absolutely nothing, wrong with staying warm by burning whatever is available. If that fuel happens to be wood, which is, from the point of view of the environment and public health probably the dirtiest fuel there is, so be it. It is cold and dark in Ontario this time of year. We need energy to stay warm and well lit. Those hundreds of thousands of people in and around Toronto who very recently experienced days without electricity know this only too well.

So it is with compassion and understanding that I point out that every kilowatt-hour (kWh) of Ontario electricity is coming at this moment with more than 125 grams of CO2. This figure, roughly 125 grams per kWh at nine-thirty on Friday January 3 2014, is called the carbon intensity per kWh, or CIPK, of grid electricity.

Together with the retail price of electricity, the CIPK is a fundamental performance metric of the sustainability of our society. The lower the CIPK and the lower the price, the more sustainable our society is, environmentally and economically. Pure and simple.

[stextbox id=”info” caption=”What is the CIPK, and how is it calculated?”]CIPK stands for CO2 Intensity Per Kilowatt-hour. It is a measure of the carbon content of a kilowatt hour of grid electricity.

The CIPK of a given grid is simply the amount of CO2 emitted by the generating plants that feed the grid with electricity, divided by the total amount of electricity fed into that grid, over a given hour. Of course, in order to calculate CIPK you have to know both of these figures.

So here is how to calculate Ontario’s grid CIPK. You need to refer to Table 1, in the upper left-hand sidebar on this page. Table 1 gives the current Ontario grid generation mix (it draws from data published at www.ieso.ca), and the CO2 emissions associated with the emitting fuel types.

  1. Go to the Total row in Table 1.
  2. Take the figure from the CO2, tons column.
  3. While still in the Total row, now take the figure in the MWh column.
  4. Divide the CO2, tons figure by the MWh figure.
  5. Multiply that result by 1,000. This converts tons-per-megawatt-hour into grams per kilowatt-hour.

Try it!


Now, is Ontario’s CIPK high? Is it low? Is it about average? The only way you can know this is to compare it with the CIPKs of other electricity grids. That is what makes CIPK such a powerful metric: it allows direct comparison of the carbon content of one grid with that of another.

Germany vs Ontario CIPK

Click on image to enlarge

Here is how the CIPK of Ontario grid electricity compared with that of Germany in 2011 and 2013.

As you can see, Ontario’s is far, far cleaner than Germany’s. Even in 2011 when the CIPK spread between the two grid was narrower, Ontario’s CIPK was not even one-quarter Germany’s.

The chart illustrates another very interesting thing: Ontario’s CIPK dropped since 2011, Germany’s went up.

  • Ontario’s CIPK of roughly 113 grams in 2011 dropped to roughly 80 in 2013.
  • Germany’s CIPK, on the other hand, actually increased—from 540 grams in 2011 to an estimated 570 grams in 2013.

Why did Ontario’s CIPK drop from 2011 to 2013 while Germany’s went up?

The answer is simple: nuclear power. Ontario added roughly 1,500 megawatts of nuclear capacity at the Bruce nuclear site after 2011. (See Bruce Power’s very interesting year-end statistical summary, and Scott Luft’s excellent analysis of the entire Ontario system.) Germany removed nuclear capacity between 2011 and now.

As a result, Ontario dumped comparatively little CO2 into the air from power generation. Germany dumped a huge amount: by my estimation nearly 350 million tons of it in 2013. That is enough to fill up Rogers Centre more than 121,000 times. (Rogers Centre with its roof closed holds roughly 2,877 metric tons of CO2 at 25 °C. It would hold a bit more at today’s temperature. To figure out how much more, use the calculations given in the expandable information box below.)

The title of this article alludes to the decision by the Ontario government to shelf the process to buy nuclear reactors from Atomic Energy of Canada Limited (AECL), the federal crown corporation that invented the nuclear reactors that are currently providing more than half Ontario’s electricity. That process would have led to an additional 2,000 megawatts of nuclear capacity in our province.

If Ontario had an additional 2,000 MW of nuclear capacity right this minute, our CIPK of grid electricity would be literally half what it is right now. (Ontario’s CIPK went up in the hour since I started writing this article: it is now, at ten-thirty a.m. on January 3, over 132 grams per kWh.) That is because we would be burning half the natural gas we are burning now. The CO2 from gas-fired power generation in the last hour was more than enough to fill the Rogers Centre with its roof closed. (To see how I arrived at that conclusion, click on the green information box below.)

[stextbox id=”info” caption=”How to calculate how much CO2 fits into Rogers Centre”]At 25 °C, Rogers Centre with its roof closed holds 2,877 metric tons of CO2. Here is how I got that number:

  1. The mass of one mole of CO2 is 44.01 grams. (Most versions of the Periodic Table, including this one, give the mass of each element. Look up carbon and oxygen—the constituent atoms in a molecule of CO2—and note their mass. Don’t confuse the atomic mass of an element with its atomic number! Add the mass of one atom of carbon, ~12.01 atomic mass units or AMU, to that of two atoms of oxygen, ~32 AMU. The result: a molecule of CO2 has a mass of 44.01 AMU. A mole of CO2 is therefore 44.01 grams.)
  2. One mole of any gas, at 25 °C and one atmosphere pressure, occupies 24.47 litres of volume. (One mole of any gas at standard temperature and pressure occupies 22.414 litres. To calculate molar volume at another temperature, let’s call it T2, with the same pressure, convert temperature to Kelvins and then multiply the ratio of the STP volume to temperature by T2; this is Charles’s Law. In this case, your T2 is 25 °C, which is 298 Kelvins: 25 + 273 = 298. Your ratio of STP volume to temperature is 22.414/273 = 0.0821. Multiply 0.0821 x 298 = 24.466 litres.)
  3. One metric tonne, or one million grams, of CO2 contains 22,727 moles: divide one million by 44.
  4. Multiply those 22,727 moles in a tonne of  CO2 by the molar volume of a gas at 25 °C, which from point 3 is 24.47 litres.
  5. Therefore one metric tonne of CO2 at the above-mentioned temperature and pressure occupies 556,136 litres.
  6. One cubic meter is 1,000 litres, so a metric tonne of CO2 occupies 556.14 cubic meters (divide the 556,136 litres of CO2 that make up a metric tonne by 1,000).
  7. Now you need to know the volume of Rogers Centre. According to Rogers, Rogers Centre’s volume is 1,600,000 m3. So divide that by 556.14 to get 2,877.[/stextbox]

That is to say, the energy that is keeping us Ontarians warm, well lit, and functioning (not to mention sane) on this deep-cold day, could be literally twice as clean as it is now.

The Ontario government scrapped the nuclear process in 2009 because it was unable to work a deal with the federal government over the price of AECL’s reactors. I won’t get into blaming either the feds or Ontario for that; that would be crying over spilt milk. As a fed-prov policy storm that could not have been better planned to keep nuclear from cleaning up our electricity, and preventing a massive amount of revenue to the cash-starved federal government and jobs for jobs-starved Ontario, it was what it was.

But I will point out that those kinds of decisions have consequences. Ontario needs energy, and on days like today we will take whatever is available. The essence of responsible planning is to make sure clean sources are available in the future.

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9 years ago

As a fed-prov policy storm that could not have been better planned to keep nuclear from cleaning up our electricity, and preventing a massive amount of revenue to the cash-starved federal government and jobs for jobs-starved Ontario

Do you believe that when governments hobble nuclear energy, they lose revenue?

The resulting increased gas use must tend to, at the very least, substantially offset any such loss.

First-world governments are in a unique position: when the prevention of the use of a dollar’s worth of uranium causes multiple dollars in fossil fuel use instead, they typically get more than a dollar in fossil fuel revenue, without any government-funded person having to spend any extra time at a fossil fuel mine.

9 years ago
Reply to  G.R.L. Cowan

Er … an almost unique position. Private fossil fuel rentiers also, of course, don’t have to do the work.

9 years ago

The lifecycle emissions of nuclear, hydro & wind are very low but not zero. It would be more realistic to use the estimates from one of the studies that have tried to quantify them, Oxford, Sovacool, IPCC, van Leeuwen.


9 years ago
Reply to  Steve Aplin

Sorry but I have to disagree with that outlook.
If CO2 emissions matter, then lifecycle emissions matter.

Either they’re real or they’re not; suspicions or obtuseness aren’t relevant.