In preparation for Earth Hour, here is some maths on the carbon emission of candles and light-bulbs.
Each hour a small candle burns about 2 1/2 grams of candlewax, containing over 2 grams of Carbon, producing 1 candlepower of light and 7 grams of CO2. So 40 candles will produce about 280 grams of CO2 each hour.
The much maligned and soon to be outlawed 40W incandescent bulb which produces the same amount of light as the 40 candles but accounts for production of about 40 grams of CO2 each hour at the power house.
A 7 Watt energy saver fluorescent bulb also produces the same amount of light while accounting for only 7 grams of CO2 each hour.
So for comparable lighting, candles produce 7 times the CO2 of incandescent bulbs or 40 times the CO2 of fluorescents.
Data used in the calculation:
- Light output of a candle is 1 unit of candlepower
- Light output of 100W incandescent bulb is approximately 100 candlepower, and a 40W bulb approximately 40 candlepower
- A 14W compact fluorescent (energy saver) bulb has the light intensity of a 75W incandescent bulb and so a 7W compact fluorescent bulb has light output of approximately 40 candlepower
- Candlewax has close to 5/6 carbon by weight
- A small candle burns 2.5g wax per hour or more than 2 g carbon/hr
- Power stations make CO2 at the rate of 1kg/kWh or 1 g/Wh