This assumes that the weather stays about the same and the energy used by the appliances that were still plugged in did not change drastically during the experiment.

     While running this experiment, remember to make allow ances for other factors. During holidays, for example, major appliances tend to be used a lot more than usual — or a lot less. And a sudden cold snap or hot spell could mean that any savings were hidden by the increased use of your central heating system or air conditioning unit. Even normal variations in usage may hide real reductions. So don’t be discouraged if your tests show smaller savings than you expected. Think of how much higher your readings would have been if all the appliances were being used.

     After this experiment your family may decide to test other energy conservation measures (like turning down the room thermostat or the setting on the hot water tank) to see how those measures affect energy consumption. Before we leave the subject of using less energy in the home, here’s a simple demonstration of how to conserve heat when cooking: