How do code refactorings affect energy usage?

Abstract

Context: Code refactoring's benefits to understandability, maintainability and extensibility are well known enough that automated support for refactoring is now common in IDEs. However, the decision to apply such transformations is currently performed without regard to the impacts of the refactorings on energy consumption. This is primarily due to a lack of information and tools to provide such relevant information to developers. Unfortunately, concerns about energy efficiency are rapidly becoming a high priority concern in many environments, including embedded systems, laptops, mobile devices, and data centers.