Look at the paper here.Abstract:
|Average across entire Alexa 100 in Internet Explorer 7.0||0.414||48.852|
|Average across entire Alexa 100 in Firefox 3.0.4||0.406||47.908|
|Average for top 10 power abusers in Internet Explorer 7.0||0.474||55.932|
|Average for top 10 power abusers in Firefox 3.0.4||0.481||56.758|
|Average for top 10 power abusers in Firefox 3.0.4 with NoScript and Adblock Plus||0.382||45.076|
To keep it short that Noscript and Adblock Plus help reduce the power consumption of the most “polluting” websites. Another good reason to use these addons.
Less power consumption is not only better for the environment, but also for the running duration of your laptop!
(Photo under creative commons from Ian Samuel's photostream)