Having a handle on your bills is always a good idea as it allows you to understand where you are spending your hard-earned money and how you might be able to save some. Information on when you are using most and least is therefore a way of experimenting to fiund out where waste can be cut out. The Efergy E2 is a great way of monitoring your electricity usage that can be linked up to your home computer to provide a visual format for studying your usage patterns.