An iron rule exists in electric power generation systems. It is quite simple. It goes like this: if you take a source of 24/7 electricity out of a system, you must replace it with another source of 24/7 electricity. Put another way: only a 24/7 source can replace a 24/7 source. By “24/7 source” I mean a type of generator that can produce a large amount of electricity—enough to power at least an entire small- or medium-size town—24 hours a day, 7 days a week. If such a generator could run hundreds of days at a time, all the better.
My real-time power generator output tables, Tables 1 and 2 in the left sidebar, contain rows indicating coal-fired output. You will notice that coal’s output in the last hour and so far today is zero. It has been that way for a few weeks. And, barring a serious event affecting our power grid, it will stay zero for the rest of today; in fact it will stay zero for the foreseeable future. I will eventually remove the row. We officially do not make electricity in Ontario with coal. Coal has been phased out of the system.
We in Ontario used to make a lot of our electricity with coal. In the year 2000, we made over 38 billion kilowatt-hours with coal (see table A13-7 in Environment Canada, National Inventory Report 1990-2009, Greenhouse Gas Sources and Sinks, Part 3, p. 50). That was out of a total of 148 billion kWh generated by all fuel types that year.
Because coal-fired output made up such a large portion of our total generation in 2000, the total carbon dioxide (CO2) emissions associated with power generation were 41.4 million metric tons.
Last year, 2013, Ontario generated 151 billion kWh. The total CO2 emissions that came with that output were barely more than 12.4 million metric tons.
To repeat: Ontario made 148 billion kWh and emitted 41.4 million tons in 2000; it made 151 billion kWh and emitted 12.4 million tons. We made 3 billion kWh more power in 2013 and emitted not even one-third the CO2 of 2000.
How is this possible? It was possible because we replaced most of the 2000 coal-fired output with nuclear output. In 2000, according to the same Environment Canada document, Ontario’s nuclear generator fleet made 59.8 billion kWh; the coal fleet made 38.8 billion. In 2013, according to my data (I go from the near realtime tables published by the Independent Electricity System Operator), Ontario’s nuclear fleet made 90.1 billion kWh; coal made just over 3 billion. That means coal made 35 billion less kWh in 2013 than it did in 2000. Well, the nuclear fleet replaced 30 billion of those kWh; the remainder were replaced by gas-fired generators.
Aside from large-scale hydropower, there are only three sources you can use to make 24/7 electricity. These are:
- Natural gas.
In Ontario, coal has been legislated out of our electricity generation mix. So for 24/7 sources, we now have only two alternatives:
- Natural gas.
If we are looking at it from an environmental point of view, keeping our eye on the concentration of CO2 in the global atmosphere—which as I write this is 401.05 parts per million (see the bottom rows in Tables 1 and 2 for the latest near-realtime readings from the Mauna Loa CO2 observatory in Hawaii)—then we ought to choose the source that emits no CO2.
Twenty-four-hour-a-day, seven days a week power that emits no CO2?
That leaves exactly one alternative.
And which one is that? I’ll give you a hint. It’s the one that is contributing by far the most electricity right now to Ontario’s grid. Again, have a look at Tables 1 and 2. What source is that?