I'm really surprised you blindly optimised "things that use energy" without looking at what actually uses energy in your house. Think of premature optimisation and profiling in programming. The same principles apply to optimising energy usage. As mentioned before, get an energy meter and measure the things (don't forget the energy use of things on standby - having them on 24 hours a day can make a huge difference). And just reading the graphs of usage distribution throughout the day, night, or over periods of weeks, months and years can tell you so much already (pretty much everything that can be said about the graphs and their implications has already been said by the other comments, so I won't repeat them). Again, it's just like profiling a program.