Look for appliances with a high Energy Rating label, but compare the annual energy-use figure as well as the number of stars. The most useful upgrades often include fridges, clothes dryers, air conditioners, televisions and hot-water systems, depending on how much you use them. Choose a size and capacity that suits your household, because an oversized appliance can use more energy than necessary. You can compare models through the official Energy Rating website, then check your retailer’s tariff and a licensed installer’s advice where installation is required.