Compact models use less energy, but they hold fewer dishes.
A compact model may actually result in greater energy use if you have to operate it more frequently. Choose a dishwasher that provides several different wash cycle selections. Keep in mind that EnergyGuide ratings for dishwasher are based on washing 322 loads annually using the normal settings. If you are considering a model with other setting options that you would use most of the time, your energy use could vary substantially.