The difference in running costs between old and new appliances can be significant. But first things first; it may be a good idea to do your own ‘energy audit’ and see just how well what you’ve got now is performing.
A cheap, plug-in energy meter and thermometer should do the trick. A fridge, for example, should be around 3-5 degrees Celsius (older ones are sometimes found to be operating outside this range, and with high energy use), and you can plug an energy meter in any appliance with a socket to measure how much electricity they’re using.