The Lifestyle Project – energy basics


A regular light bulb uses 60 W of power.  Higher-powered bulbs can use much more than that–well over 100 W–while compact fluorescent bulbs use much less (15 to 20 W) and LED bulbs use less still.  


Operating a 60 W bulb for 17 hours uses about 1 kilowatt hour (1 kwh) of energy, which is about the same amount of energy that is in 9 tablespoons of peanut butter. (approx. ¼ of a 500 ml jar).


As shown in the table below, other common things in our homes use a lot more energy than a single light bulb.  A computer uses the equivalent of three 60 w bulbs, a large TV uses twice that amount.  A hair dryer or a small heater uses 25 times as much and a typical clothes dryer 83 times as much.



Regular light bulb

60 watts


150 watts (~3 light bulbs)

Large TV

350 watts (~6 light bulbs)

Hair dryer or small heating unit

1500 watts (25 light bulbs)

Hot water heater

4000 watts (66 light bulbs)

Clothes dryer

5000 watts (83 light bulbs)


The energy use of vehicles is significantly greater than that used in our homes and offices,


An average-sized car being driven at 50 km/h in the city uses gas at a rate of about half a cup per minute (100 ml) or 1/3 of a teaspoon every second.  But gas has a lot of chemical energy in it.  In terms of the amount of energy used, this is equivalent to running about 969 60-watt light bulbs!


Because cars tend to be less fuel-efficient at higher speeds, driving at highway speed (say 100 km/h) uses considerably more than twice as much energy as driving at city speed.


Average-sized car

58000 watts (969 light bulbs)






Steven Earle

March 2006