This paper introduces LogicCrowd, a declarative programming platform for mobile crowdsourcing applications (using social media networks and peer-to-peer networks), developed as an extension of Prolog. We present a study of energy consumption characteristics for our LogicCrowd prototype. Based on the measurements, we develop an energy-crowdsourcing consumption model for LogicCrowd on the Android platform and also extend the Logic-Crowd meta-interpreter for computing with an energy budget corresponding to a certain battery lifetime.