Most DC versions of appliances are less energy efficient than their AC equivalents, with few qualifying for the Department of Energy's Energy Star certification for energy efficiency. However, specific models of energy-efficient DC appliances are available.
Appliances using AC power tend to be more efficient than those using DC power due to difficulties involved in modulating the voltage of DC current. However, while DC appliances are often less efficient than their AC counterparts, a growing number of energy-efficient devices already use direct current as a standard. For example, highly efficient LED lights already must use DC power, and convert AC input to DC at the light itself when installed in AC sockets.