HOW MUCH CO2 DOES A LIGHT BULB CREATE?

You might well be confused by all this talk about Carbon Dioxide (CO2) and light bulbs. Why do the government and environmental authorities say that the move to energy saving light bulbs is so important and why has legislation been put in place to progressively ban the incandescent light bulb. Some people say, a light bulbs is a sealed glass unit so how can it produce any CO2 anyway?

Well it is not the light bulb itself but it is the CO2 created in the generation of the electricity that the light bulb consumes. Now clearly the amount of C02 created will depend on the type and the efficiency of the power station which is worst for coal power stations but if your electricity is generated by wind power then your light bulb will not be responsible for creating any CO2 at all during its operation. But right now the majority of electricity is generated by coal powered stations so lets look at the figures for those.

Average CO2 emissions (in Grams) for generating 1KWh electricity (by source):

Source	Grams of CO2 produced
Coal	870
Oil	650
Natural gas	487
Nuclear energy	16
Hydropower	20
Wind energy	11

Source – Gridwatch.co.uk

Lighting Technology (800 Lumens)	Daily Kwh Consumed (@8hr)	Annual Kwh Consumed (@8hr/day)	Co2 Produced (Coal Based Power Generation)
Incandescent (60 Watts)	0.48	175.2	152.42 Kg
Halogen (42 Watts)	0.34	124.1	107.96 Kg
CFL (14 Watts)	0.11	40.15	34.93 Kg
LED (9 Watts)	0.07	25.55	22.23 Kg

Power Station Pollutants

The 3 main pollutants produced by a powers station are:-

1. Sulphur Dioxide, which is responsible for acid rain, is produced at 20 tons per year for a 1 Mega Watt mini electricity generating station
2. Nitrogen Oxide, which is responsible for smog, is produced at 20 tons for a 1 Mega Watt mini electricity generating station
3. Carbon Dioxide CO2, which is thought to be responsible for global warning, is produced at 7500 tons for 1 Mega Watt mini electricity generating station

Now when you consider that a typical commercial electricity generating station would be 500 Mega Watt capacity then it is clear to see that the burning of coal produces massive amounts of pollutants.

Then looking at CO2 in more detail, if you had a 100 watt light bulb and left it on all year then the generating station would create 750kg of CO2 during that year. Now it is unlikely that you would have a light bulb on continuously by lets say you have the light bulb on for 4 hours each day then that is still responsible for the creation of 125kg of CO2. So that means that if you change your light bulb for an energy saving CFL which will only consume 80% of the energy then you will help save the environment by reducing CO2 emissions by 100kg every year.

Then to put this in perspective in 2007 around 19% of all electricity generated was used for lighting purposes which is a very significant proportion. This means that a reduction in energy consumption in lighting has a major impact on overall CO2 emissions.

The other key fact to put this into perspective is that electricity generation account for around 70% of the CO2 emissions for cars and three times the total emissions from aviation as quoted by the International Energy Association (IEA). Clearly with these statistics then the migration from the incandescent light bulb to the energy saving light bulb will be a major contributor in reducing CO2 and global warming.