Incandescent ban illuminates urgent need for public carbon education

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.

The much maligned incandescent light bulb. Most days of the year in Ontario, the heat produced by this device is useful. And it is, today anyway, much cleaner than the heat produced by natural gas.

The much maligned incandescent light bulb. Most days of the year in Ontario, the heat produced by this device is useful. And it is, today anyway, much cleaner than the heat produced by natural gas.

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.

[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, 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!


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.

Click to enlarge

If it’s cold outside and you need all the heat you can get, then it makes sense to use incandescent lights: most of the electricity they use is turned into heat. This chart shows how much carbon dioxide (CO2) comes with using natural gas versus Ontario grid electricity to get 0.95 kilowatt-hours of heat. As you can see, Ontario electricity contains less than half as much CO2 as natural gas. Click to enlarge

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.

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James Greenidge
9 years ago

Amen. When you have a near inexhaustible power source, who cares how much or how you use it as long as its clean and cheap? A home thermostat includes the heat of humans and light bulbs in its thermal budget, so if bulbs take a little load off a furnace that’s great too! The big laugh here in NYC three winters ago was the big freeze which caused mucho traffic snarls because snow completely covered and masked the new LED traffic lights — forcing the city to send out crews in the night to clean them off! They were thinking of “fixing” the problem — with LED heaters! (These green decisions must be secretly made by the same German courts who close perfectly sound nuclear plants sheerly out of wild fear..)

James Greenidge
Queens NY

9 years ago


Snow on LEDs can definitely be a problem.

In my town of Hartford, VT, we decided to switch street lights over to LED and wait on the traffic light switch. Street lights face down, and they don’t accumulate snow. That decision was made during the time when I was on the town energy commission a few years ago. They might be considering a traffic light switch now–I don’t know.


peter dublin
9 years ago

Nat Resource Gov Ministry own research showed the heat usefulness
— seemingly then ignored in the supposed proposal savings!

peter dublin
9 years ago

comments in moderation!

peter dublin
9 years ago

There is a still bigger issue about why light bulb energy savings don’t meaningfully hold up – even ignoring the heat factor

Light bulbs don’t burn coal or release CO2 gas.
Power plants might – and might not.
If there’s a problem – deal with the problem.
In Canada, hardly a problem, given Canada 86% emission-free electricity, and of course coal itself can be treated in various ways.

Unlike cars, light bulbs don’t burn fossil fuel or release CO2 gas
Power plants might, and might not.
If there’s a problem – Deal with the problem.
Incandescent use is mainly off-peak evening surplus electricity –
which is why those rates are cheaper on time based pricing – hardly
“saving power plants” even on supposed savings.
In particular coal plants, the main worry, effectively burn the same
coal anyway on minimum night cycle for operational reasons (cost in wear and tear, and slow stoking up to daytime levels), again referenced, DEFRA, APTECH and power plant commission references

So, little if any society energy/emission savings
– especially adding life cycle (mining to recycling, and extra
transport in all stages) of complex CFL-LED replacements, remembering
that simple patent-free generic bulbs are much easier to make locally
by small/new outfits. thereby also sparing the dirty bunker oil
powered China ships bringing in CFLs and LEDs.

So it’s understandable why major manufacturers don’t voluntarily stop making them, but lobby for ban to stop any competition to their own more profitable expensive patented CFL/LEDs (as they admit).

9 years ago

I’ve got a correction and a disagreement.

First, the correction:  the 1.00 kWh of electricity turns into very close to 1.00 kWh of heat, because surfaces do not reflect perfectly and very little light is lost to the environment through windows and such.

Second, the disagreement:  the incandescent light is a half-assed solution to the “heat problem”.  (A) it’s seasonally wrong:  you use it more in the dark but warmer late autumn than in the brighter but colder late winter.  (B) it’s wrong for time of day:  you need more heat overnight when it’s colder, but the lights are on in the evening.

If you need light but not heat, an efficient light is the best thing to use.  If you need heat but not light, a heater is the best thing to use.  Something with a large undesired byproduct can be a hindrance as much as a help.

My suggestion?  Go with the efficient lights, build more nuclear plants, and use electric central and baseboard/radiant heat to run those nuclear plants at 100.0% through the whole heating season.  Use combustion heat only for backup.  If you can heat just the bedrooms and upstairs baths overnight (almost trivial with electric heat), gas furnaces can shut down with no loss of comfort.  Best of all, you’re not dumping heat into living spaces on hot summer nights!

6 years ago
Reply to  Engineer-Poet

Missing the point altogether in this post. The heat from the light bulb is not the primary heat source. It is not wasted heat because it will reduce the heating demand.

The point is the green group go “Hot light bad”, “Kill bad light”, and the government says “get rid of incandescent lamps and we reduce the need for expansion of the grid. For the utilities and government it has little to do with going green and a lot to do with managing growth of demand on the electrical grid.

Jaro Franta
9 years ago

What is a HEATBALL®?
A HEATBALL® is not a light bulb, but fits into the same socket!
The most original invention since the electric light bulb! Although a heatball is technically very similar to a light bulb, it is a heater rather than a source of light.
Heatballs fit into commonly found E27 and E14 sockets. Its efficiency [more…] is unprecedented.

9 years ago
Reply to  Jaro Franta

They briefly sold something like this a long time ago, looking like a infra-red light bulb, but they went out of style when space heaters became more conveienent and controllable.

Phil Hamm
9 years ago

Let’s think holistically here. How much energy went into the material and manufacture of the two light bulbs? I’m willing to bet if you take that into account the CFL looks even worse than you’ve presented here.

Also, CFLs tend to work poorly unless they are on for an extended period of time. Bathrooms, closets, garages, laundry rooms, any place when you walk in, turn on the light, then walk out, is a very poor match for CFL bulbs. They will fail quickly, sometimes in less time than incandescants would.