We present a prototype web service that enables researchers to evaluate the performance per watt of semantic web tools. The web service provides access to a hardware platform for collecting power consumption data for a mobile device. Experiments are specified using RDF to define the conditions of the experiment, the operations that compose those conditions, and how they are combined into individual execution plans. Further, experimental descriptions and their provenance are published as linked data, allowing others to easily repeat experiments. We will demonstrate how we have used the system to date, how others can use it, and discuss its potential to revolutionize design and development of semantically enabled mobile applications.