Do CFLs Make Sense for BC?

A Compact Fluorescent Bulb (Wikipedia)

I recently noticed that BC has banned 75W and 100W incandescent light bulbs.  I was just wondering whether BC actually needs to legislate a more efficient light bulb, or whether it is even more efficient for many applications.  I'm not going to go into the aesthetics of the light from CFLs versus incandescents.  Frankly I doesn't bother me but I do appreciate that it bothers lots of people.  Rather I would like to look at the energetics.  

The basic assumption is that the heat produced by light bulbs is an inefficiency.   This is clear if you have lighting in a space that is air conditioned, but it isn't so clear in a space that you heat (at least not to me).  BC is not nearly as cold as other portions of Canada but it isn't Arizona either.  The times that we use lighting happened to coincide with the times when we use the heating, so the heat generated by the light bulbs actually slightly reduces the energy required by our boiler to heat the house.

I'm not the first to point this out.  I would suggest that you look at the CBC report http://www.cbc.ca/news/canada/manitoba/story/2009/03/04/mb-light-bulbs.html
and the comments that it generated.

Much of the question in a cool place like BC comes down to the efficiency of producing heat with your boiler (about 85-95%) versus electrically.   If the electricity is produced hydroelectrically the efficiency is similar (about 80%), but no greenhouse emissions are produced.   However, if the electricity is produced by burning fossil fuels the efficiency is typically 40%, so you in net end up burning about twice as much fuel if you heat electrically versus with your own boiler or furnace.   One might argue that since BC produces a lot of electricity with hydro, electric heating is 80% efficient and produces no greenhouse gases.   It isn't that simple, because not all of BC electricity is produced with hydro and some electricity is sent to regions with fossil fuel electricity, so using electric heat will cause more fossil fuels to be consumed.

Using the 40% efficiency rate, the 60W light bulb gives about 15W of light and 45W of electric heat (the latter required about 100W worth of fossil fuels to be consumed) but only displaces 45W of fossil fuel in your how furnace.  Let's look at the total energy used by both bulbs.

• Incandescent uses 60W at 40% efficiency, so 150W of fossil fuels.
• CFL uses 15W (40W of fossil fuels at the electric plant) for light plus 50W (to make up the extra heating), totalling 90W, so the CFL uses about 40% less fossil fuel for the same amount of light and heat.  (Not the 75% that you get from comparing the wattages).

If you assumed that the electricity production is more than 90% efficient, the traditional light bulbs and CFLs are neck in neck.

• Incandescent uses 60W at 90% efficiency, so 67W of energy.
• CFL uses 15W (17W of energy at the electric plant) for light plus 50W (to make up the extra heating), totalling 67W, so the CFL uses about same amounts of energy for the same amount of light and heat.

If one argues that hydro-power is clean (and more power generation doesn't cause fossil fuels to be consumed) and we aren't worried about energy consumption but rather greenhouse gases, then the incandescent light comes on top.

This doesn't take into account how much energy it takes to make and dispose of a light bulb.  This complicates matters a bit because CFLs are costly but last a longer time and incandescents don't require much energy to produce but don't last as long.

However, all these arguments are turned on their head as soon as you turn off the heat and turn on the A/C or even crack a window.   In the first case the heat produced causes more energy to be consumed to move it outside, or in the second case it is simply lost to the environment.

I looks like CFLs make sense for BC and make even more sense in places with A/C, but if you live off of the grid and have a clean electric source (how about your own solar panels or hydro dam), then you can happily use incandescent bulbs and help the Earth because you won't have to use as much energy to heat your house.