An Ewave convection oven is not more energy efficient than other convection ovens. In their article, "Better Cooking Through Convection," Fine Cooking reports that a convection oven will cook food about 25% faster than a conventional oven. Ewave's own user manual reports a 25-30% faster cooking time.
The efficiency of a convection oven depends on how quickly food is prepared and varies with each type of food. The Ewave convection oven fits into a relatively new category of countertop convection ovens, which satisfy a need for healthy eating without taking up the space of a microwave oven or the expense of a full-size convection oven or range.