In the recent deep freeze, I used and was extremely grateful for every watt of heat in my home. I needed it. As I mentioned last post, when it is that cold I don’t really care where the thousands of watts I use came from. Gasoline, wood, coal… I really do not care. I just need the heat.
In my better moments though, I do care about how the heat is made. If I can get heat from a low- or zero-carbon source, I am more than happy to choose it over stuff like gasoline or wood. And because I know something about the carbon content of each watt of heat from the different things that make heat, and because I live in Ontario, I would choose Ontario grid electricity over every other source that is available to me.
This is why I shake my head when governments buy into the pseudo-green groupthink that produced the ban on incandescent lightbulbs in Canada. Incandescent lightbulbs convert most of the electricity running through them into heat; only a small percentage—as little as five percent, according to this Popular Mechanics article—goes into producing light. My take on that is: who cares.
In Toronto, Ontario’s capital and Canada’s biggest city, artificial heat is used pretty much from September 15 to June 1. (A city bylaw requires landlords to provide artificial heat to rented homes so that their indoor temperature is maintained at at least 21 °C.) That means that from Sept. 15 to June 1—i.e., in 259 days out of the year—the heat produced by an indandescent lightbulb is actually useful in Toronto residences. Who cares if an incandescent lightbulb turns most of the electricity running through it into heat.
Now, what is the environmental upshot of that electric heat? You can measure this very easily. Table 1 in the left-hand sidebar provides the hourly carbon content of Ontario electricity. This is given in the bottom row of the Table, and is called the CO2 intensity per kilowatt-hour (CIPK) of grid electricity. At eight a.m. today (January 16 2014), Ontario’s CIPK of grid electricity was 54.3 grams. The CIPK varies from hour to hour, depending on the generators that feed the grid in each hour. With the current mix of generation sources, Ontario’s CIPK averaged over a year is around 82 grams.
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.
- Go to the Total row in Table 1.
- Take the figure from the CO2, tons column.
- While still in the Total row, now take the figure in the MWh column.
- Divide the CO2, tons figure by the MWh figure.
- Multiply that result by 1,000. This converts tons-per-megawatt-hour into grams per kilowatt-hour.
Let’s use the 82 grams. Let’s say you run ten 100-watt incandescent lights for one hour; you use one kilowatt-hour’s worth of electricity (10 x 100 watts = 1,000 watts of 1 kilowatt, run for 1 hour = 1 kilowatt-hour). Well, incandescents turn only 5 percent of their electricity into light; the rest turns into heat. So that 1 kWh of electricity turns into 0.95 kWh of heat.
Using the Ontario average annual CIPK of 82 grams, that 0.95 kWh of electrically generated heat comes with 77.9 grams of CO2.
How does that compare with 0.95 kWh of heat from some other source, say natural gas?
- That 0.95 kWh works out to 3,242 British Thermal Units (BTU). (One BTU = 1055 Joules. A watt is defined as 1 Joule per second, so a kilowatt-hour is 1,000 Joules per second x 3,600 seconds in an hour = 3.6 million Joules. Therefore 95 percent of 3.6 million Joules = 3.42 million J; divide by 1055 = 3,242 BTU.
- 3,242 BTU of natural gas fits into a volume of 0.089 cubic meters; see this NETL calculator.
- According to Environment Canada, each cubic meter of natural gas turns into 1,879 grams of CO2 when reacted with oxygen (i.e., burned).
- Which means those 0.089 cubic meters of natural gas to make the 0.95 kWh of heat will turn into 167 grams of CO2 in the course of making 0.95 kWh of heat.
To give the stark comparison:
To make 0.95 kWh of heat, Ontario grid electricity comes with 77.9 grams of CO2.
Using a natural gas-fired heater to provide the 0.95 kWh of heat, assuming perfect efficiency (which in the case of a combustible heat source is thermodynamically impossible), you would produce 167 grams of CO2.
So here is a question for David Suzuki and all those applauding the ban on incandescent lights:
Is it better to put 77.9 grams or 167 grams of CO2 into the air?
It is pretty clear that for 259 days of the year in Toronto Ontario (and more than 259 days in points further north), the heat from an indandescent light is actually beneficial. And with Ontario grid electricity being as clean as it is today, that heat from the incandescent light is demonstrably and provably cleaner than that from the next-cleanest dedicated heat source.