Photo: Compact fluorescent bulbs: Shedding light on emission reductions

By Tyler Bryant, Energy Policy Analyst

B.C. is phasing out incandescent bulbs for home use, and that's raised some interesting questions about the environmental and health impacts of the bulbs that are replacing them. My colleague Lindsay Coulter outlined some of the ways to properly dispose of compact fluorescent bulbs. But some people are rightly questioning what the total greenhouse gas impact of the CFL phase-in will be if we account for the energy incandescents provide to heat our homes.

The Vancouver Sun reported BC Hydro's estimate that the new CFL bulbs will increase B.C.'s GHG emissions by 45 kilotonnes. I don't know how BC Hydro came up with this estimate, but I assume that the utility looked at the additional energy required to make up for the lost heat from incandescents and calculated the emissions split between homes heated by electricity and homes heated by natural gas. If all of the heat energy from incandescents went to heat homes, the electricity and GHG savings would be zero because just as much electricity would be required to replace that lost heat. Because incandescents and electrical element heaters have the same efficiency, there would be no net effect on energy and GHG savings. And so, the increase in provincial emissions would come from homes heated with natural gas as more natural gas would be needed in home furnaces to make up for the lost heat.

But there are a number of problems with this type of calculation. First, CFLs actually lead to a net energy savings even when accounting for the lost heat. In 2008, Natural Resources Canada and the CMHC studied the net energy savings when accounting for heat loss. They found that in all cases, CFL bulbs lead to total energy savings. Why? For a couple of reasons. First, not all of the heat from incandescent bulbs was used; bulbs close to windows or recessed in ceiling light holders do not provide useful heat. Second, the heat from incandescents is not helpful during warmer seasons and can lead to more energy consumed by air conditioners to cool homes. Because seasons are so variable across the country, the study looked at homes in a number of different locales. In Vancouver, for example, CFLs reduced energy by 318 kWh per year while the increase in heating energy required was 201 kWh for electric-heated homes and approximately 226 kWh for natural-gas-heated homes. Therefore, electricity emissions would drop while natural gas emissions would increase. Because the emissions footprint of B.C.'s electricity system is quite low because of its reliance on hydropower, the additional natural gas used for heat would result in an increase in emissions.

But, this is only looking at B.C. If we look at the total electricity system, the story gets more interesting. B.C. imports significant amounts of electricity annually from Alberta and the U.S. This imported electricity is more GHG-intensive as it is either coal fired (from Alberta) or natural gas fired (from the U.S.). To put it in perspective, B.C.'s average emissions from an additional kWh of electricity generated is about 28 grams of CO2. For coal-fired electricity it is 800 to 900 grams and for natural gas it is 200 grams. That means that if the electricity savings from CFL bulbs go, in part, to reducing imports, then the effect on total emissions will be positive.

And because natural-gas furnaces are anywhere from 80 to 97 per cent efficient in Canada, between 80 and 97 per cent of the energy in the combusted gas goes to useful heating. This is important to understand if we start replacing incandescent heat with natural gas furnace heat. Why? Because imported electricity used to power the incandescent light bulbs is much more inefficiently produced than a natural gas furnace. The best efficiency natural gas generating stations achieve 60 per cent efficiency, and coal plants are anywhere from 25 to 40 per cent efficient at producing electricity. So when you use incandescents for heat, you've already lost a significant amount of energy by the time the electricity reaches your light bulb. Significantly more energy is used than with a natural gas furnace.

As a result, if we look at system emissions, (which is what is really important for a global pollutant like CO2), total emissions from using CFL lights will be lower.

February 4, 2011

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Feb 09, 2013
1:34 PM

I really believe that with the LED technology the Compact Fluorescent bulbs should be phased out, the risk of hazard is not really worth the benefit anymore.

Mar 19, 2012
12:39 PM

As follow-up on CFL

Mar 11, 2012
6:04 AM

in my house, we have replaced all our incandescent with CFLs. Led bulbs are good too just a little bit expensive.

Renewable Energy News

Dec 20, 2011
8:02 AM

If a bulb gets broken, how do we clean it up?

I read that if we use a vacuum that we will need to pay to dispose of the vacuum cleaner as it is now considered contaminated.

Dec 16, 2011
7:01 PM

I have a visual structure dysfunction. CFL's give me headaches just like florescent tubes do. I have a house that has some lovely shades of creams and yellows on the wall and insulating curtains. CFL's turn them some horrid shades of green. THAT makes me very cranky.

We have 38 windows in our house. Lots of different sizes. My art studio is in the house. We hardly ever turn the lights on until it is really dark out.

I have several strands of LED lights, coloured and warm white. They work really well for general lighting, mood lighting. And I have several strands that I keep with batteries for the times when the power goes out. We are usually the last ones in the area to get our power back.

We use regular light bulbs for task lighting and doing artwork because CFL's do not let me see what I am doing three dimensionally.

I saw a French documentary about the people who live near a CFL bulb manufacturing plant. Their water is polluted with industrial waste and mercury runoff. Their food crops were ruined and there was no compensation or health care for those who were ill.

Having studied the effects of mercury poisoning in Japan , called Minimata Disease, there were people in the doc that were exhibiting early signs of permanent damage. China's regulations for these environmental toxins are tissue paper thin.

I cannot in all good conscience use something that causes me illness and other people such needless suffering.

I will wait until LED's are really filling the market.

reeni Pardy

Nov 25, 2011
5:38 PM

I’m keeping an eye on light emitting diode technology. I have been experimenting with some of the more recent ones and they show a lot of promise without the mercury content of cfl’s. When using these the location and type of fixture is important for best result but anyway you look at it being green means getting by with lower overall illumination levels and that’s not necessarily a bad thing.

We should all be looking at ways of getting off the grid which is truly a wasteful thing. The facts of electrical power transmission are that you get maximum power transfer from source to load when the load receives a mere 50% of the generated power no matter what the generator efficiency. The rest is lost as heat and in Ontario we get to pay for these losses on our bill. If you can get off grid you can tailor a system that does not have to work at mpt because your goal isn’t maxing out the dollars earned from a grid and generator located miles from the load. The other benefit to getting off grid is not paying the fee that’s added to your bill just for being connected to it even when you use 0 Kwh ! Being minus one utility bill would be a nice thing.

Getting off the grid is feasible even without solar or wind by generating both heat, cooling and electricity from natural gas at the point of use. Of course you can augment this co-generation with solar or wind and other technologies with a bit more expense and this would reduce carbon footprints even more. Getting by without any natural gas is expensive and a bit tricky but also possible at present.

Sep 20, 2011
8:22 PM

I just saw a "Power Saver" by, which says it will reduce our energy consumption on washing machines, refrigerators, etc by 15%. Sounds too good to be true. Is it?

Sep 14, 2011
11:38 PM

Compare the weight of the glass in both bulbs, not even close the cfl bulbs use far more. Compare the ceramic base to the thin aluminium base, the ceramic uses far more energy to produce. I removed the base on one and found a circuit board including a small transformer. Please dont tell me that took very little energy to produce. Cfl's also use rare earth elements found in very few places in the world. Special disposal uses extensive energy. There really is no comparison, regular bulbs use far less energy when everything is taken into consideration. But light bulbs use so little energy to begin with that the whole issue is a red herring. Industry wastes massive amounts of energy. I should know I am one of the electricians in charge of keeping things running. A few counterweights and flywheels would easily power up every light bulb in the country with the energy savings by switching from kinetic to potential energy then back when it is needed. Why dosn't Mr. Suzuki ever mention this? Every time I need to shut off then restart one of the many 300 HP motors I think of this. There are many simple ways to cut back just ask the people that work with energy on a daily basis. Unfortunately we get stuck in these silly arguments about the most simplistic energy saving devices.I have yet to find any enviromental group willing to listen to reason or ideas. It's akin to fiddling while the whole earth burns.

Sep 12, 2011
8:42 AM

An electrician just showed me the 6" retrofit LED unit and says that (contrary to how I interpreted above the manufacturers' elaborate technical argument for superior light distribution compensating for much less lumens than CFL's), the 6" units do provide a good quantity of light.

The reason I was skeptical is that my earlier client had serious vision loss and needs more than normal light levels, and a friend in the fluorescent lighting business recommended staying with fluorescent or even halogen in that particular case. On my current job the electrician is installing LED lights, and this particular retrofit unit is quite a good deal at $120/unit, as a competing company's non-retrofit 6" LED pot runs $200/unit. This Lithonia retrofit unit he showed me has a medium base at the top of a massive aluminum heat sink that fills an existing can quite snugly.

Some people also just like lots of light and a high colour rendering index. When I moved in with my wife and began turning off lights I thought unnecessary her rejoiner was "I am not a mushroom!" , so for LED's I'll first try replacing my existing 26 W Daylight Helical 26W FLE26HT3/2/D CFL (CRI 82) that hangs proud via socket extension from my study ceiling pot. Plus this CFL feels quite hot (but no where near an incandescent bulb's temperature) as I take it down from the pot-light, which may be a sign it's best not used upsidedown despite the maker's assurances to the contrary. While the Electrical Safety Authority says that pin-holes and scorching of the fire-resistant plastic base of CFL bulbs is a "normal failure mode" for CFL's, I'm not sure I want to see many repeats of this failure I saw in an earlier CFL bulb of a different brand, or shorter bulb life from non upright use.

Aug 07, 2011
6:58 AM

While LED’s certainly look to be the way of the future, for the next couple of years I’d stick with fluorescent in residential applications. LED manufacturers upsell efficiency over inadequate light (at least for 6” pots; 8” would look massive in a house, but could work if cost similar) from their existing potlight designs, as the total lumens are about half what you get from fluorescent pots, giving a ghost-like effect in both quality & quantity of light.

I don’t know why they just don’t put more LED’s per bulb on them, one person said they don’t to avoid losing market share as bulbs last too long, however this sounds a little too pat.

This Green Building forum thread also recommended fluorescent over LED for now.

Jun 13, 2011
10:33 AM

Hydro paid for a study and have not published the results . Why not ask them for the data.Hey I just had a brilliant idea, why not do your own research? Have you considered the carbon footprint of this technology in a cradle to grave analysis? If you calculate the enormous amount of energy required to mine the minerals, manufacture the components, get them all to the assembly plant in China,take into account the coal fired power they consume, the human rights violations in China and their atrocious environmental record, rivers running black with lethal mercury and other toxic agents, then there is the enormous cost of the plastic packaging to make and dispose of, the shipping in oil powered freighters the retail stream,the consumer stream, the disposal stream,the 50,000 tons of mercury in landfills, into our water, into our fish ,into our bodies permanently, every year, the poisoning of our natural environment and our children and loved ones, how do put death and destruction into a carbon footprint analysis? Incandescent lights are not without their own environmental footprint but the two technologies just do not compare on the destruction gage. Walter Patrick McGinnis

Mar 18, 2011
7:29 PM

The amount of mercury in a CFL is as low as 1 milligram. Since coal-fired electrical generating plants contribute significantly higher amounts of mercury in daily operations, use of CFL’s actually reduces the amount of mercury introduced into the environment. If you use regular fluorescent bulbs, you’re already involved in the issue, because all fluorescent lighting involves the use of mercury.

Personally, I much prefer fluorescent over incandescent in terms of colour and intensity; but that’s just personal preference.

Feb 26, 2011
11:50 AM

with the evidence about cfls and the risks associated with them i am surprised that they are being endorsed on the site….mercury… i hardly expect most consumers are going to handle these cfl’s efficiently due to time constraints, access to recycling centres (hmm i have little faith that people wil take time in their lives to make a special trip to dispose of cfls. and the risks of storing them before ridding them are hazardous. this is something that the advocates and the the cfl pushers have failed to take into consideration. these bulbs are banned in europe. i have stocked up on the traditional incandescent bulbs until i can find a more efficient way to light up my life.

Feb 14, 2011
6:17 PM

We are trying to understand this whole issue of CFL light bulbs and we are having a difficult time. We have always believed we export hydro energy to California not the other way around. Remember the issue of how much to charge our friends to the south? We agree we need to find ways to cut back on emissions and David Suzuki suggests this is an important step. It is, if our citizens in North America are responsible recyclers. Some are, most aren’t.
Our concern is, even if the mercury emissions are low with one bulb, what about millions and millions of them? We are told these new bulbs will last 7 years. Try one week. We save our receipts because not one bulb has lived up to the promise. And, for now, what about choice? If we believe that everyone could be responsible recyclers (back to the retailer) and we had a responsible disposable system in place, then maybe. We want the best for our planet…and don’t know how this could be the correct answer. We will get there but not yet.

Feb 14, 2011
3:25 PM

Thanks for your feedback everyone. Many of you have highlighted concerns regarding the mercury content of CFL bulbs. We should be trying to limit our exposure to toxic substances in all consumer products including lighting. Environment Canada is in the process of regulating the mercury content of CFL bulbs LEDs also need to be a part of the solution due to their greater efficiency and not being reliant on mercury to operate.

In terms of the impact that mercury from discarded CFLs will have on the environment, the EPA estimates that if all 290 million CFLs sold in the US in 2007 were sent to a landfill instead of being properly recycled that it would amount to 0.1 per cent of their total mercury emissions The majority of US mercury emissions come from coal fired power. Energy efficiency measures including lighting can put a dent in the amount of power needed from these sources. Even in Canada where our electricity is cleaner overall than in the US, coal fired power is still a major source of environmental mercury contamination. A net-reduction in mercury emissions will benefit the environment and also benefit humans because our main exposure to mercury is through the fish we eat. Emissions from industry find their way into waterways and the mercury bioaccumulates as it works its way up the food chain, eventually reaching higher than advisable concentrations in larger fish such as tuna.

-Ryan (DSF)

Feb 09, 2011
4:43 PM

Why are we not looking at total embodied energy when trying to determine efficiency or net impact on GHG? Cost to manufacture,import resources for manufacturing,distribution of the product and disposal. I hope the CFL still comes out on top.

Feb 07, 2011
4:08 PM

Mr. Suzuki, CFLs are a can of worms you shouldn’t be condoning. Peter Kent, Conservative environment Minister state last week there isn’t any recycling program in place for these polluting light bulbs. I’ve been in the lighting biz for 30 years and can honestly say these bulbs give off the most horrible quality of light as anything I’ve seen I’ve had numerous complaints that people get headaches when n a room illuminated by CFL’s.

If people want to save energy, put all your lights on dimmers, dimming a incandescent bulb 10% extends their life by 45%. Incandescent bulbs don’t have Mercury in them, you don’t have to wear a respirator if you smash one. Not in the calculations of energy used by CFLs, the energy used to so called recycle them.

The only thing green about them is the sickly greenish hue that they emit!!

Feb 07, 2011
2:37 PM

“if the electricity savings from CFL bulbs go, in part, to reducing imports…”

That’s a BIG if.

Feb 05, 2011
10:04 PM

Great article. I’ve enjoyed this contributions. Its nice to see every questions answered in a blog post like this.

Feb 05, 2011
5:02 PM

So, Dr, Suzuki…now because of you and all the Greeners , we no longer have incandescent light, what happens when the mercury bulb explodes in an oven or a refrigerator…we poison our ovens and fridges because you advocate these mercury light bulbs,,and where do you think they will land?? the landfill of course..because those citizens of BC will not know the extreme dangers of the mercury in these bulbs..what a piece of work you have advocatd for these toxic bulbs..thank you for incouraging mercuring filled bulbs….really smart…for a Doctor

Feb 05, 2011
3:22 PM

LIfe isn’t as simple as the total GHG emmisions, even when including how electricty is produced. What about the cost to manufacture and dispose of CFLs? And because of its toxicity,handling a broken CFL is not simple ( No way will I buy them!

I’m biting the bullet and replacing bulbs in use for >4 hrs a day (kitchen, hallway) with LEDs from a Canadian supplier who provides a 2 year warranty. The payback period, when factoring in the cost of replacing PAR20 halogens that never get anywhere near their stated life of 1000 or 2000 hours, even when on a dimmer circuit — is about 4 years.

As for the other bulbs, I’ll hold off replacing them until the ESL bulbs become available.

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