Power Consumption - Laptops are better than Desktop computers

Whey laptops are power efficient? 

From the initial days of laptops or notebook computers, they have been including chargeable batteries that allow the computers to run without power supply for some time. To increase the operating time on a given battery, the computer components have been designed for laptops to consume low power.

How power efficient are laptops compared to the desktop?
Laptop computers are as powerful as their desktop versions in capability, but they normally save more than 85% power when computing at their maximum capacities. This graph shows a typical comparison:

For example, a laptop is costing 65 watts of power. While average desktop computers cost more than 450 watts of power. It also depends if you are using an LCD or a CRT monitor on the desktop. CRT monitors take significantly more power than LCD monitors.