|Estimating the power used by all US computers||The population of the US is about 260 million people. Many
have computers and many do not.
Let us estimate that there are 50 million computers in the US.
A computer and its monitor each consume about 100 watts. Let us estimate that each US computer system is turned on 50% of the time. Therefore, one-half of the 200 turned-on watts is the around-the-clock average power consumption, namely 100 watts.
Then the average electrical power used for running the 50 million computers is 5 billion watts, the full power output of five very large power stations.
By comparison, during the period 1985 to 1997, the US electrical power demand grew about 90 billion watts.