The average home uses 30% of its energy in the kitchen. The smallest appliance for the job is the most efficient one. Use the microwave or a toaster oven for small jobs. And multitask. Use a Chinese steamer, for example, which can cook different dishes on different tiers simultaneously. Or be creative; cook your potatoes in the bottom of a double boiler while making a sauce or custard in the top.
While bringing a pot of water to boil for pasta, replace the lid with a suitably sized bowl filled with pasta sauce to heat. In the oven, stagger dishes at different rack levels and time your cookie baking for right after you finish roasting or baking larger items. The retained heat will practically give a sheet of cookies a free ride in terms of energy use. And be sure to run your dishwasher only when it’s full and allow the dishes to air dry – it will save 20% of the dishwasher’s energy use.