With the promise of delivering immortality, energy harvesting and wireless energy transfer have become the next research frontier for pervasive computing and networks. The challenge still is to adapt operations along all aspects of a sensing system (sensing, computation, communication), to deal with the varied, unpredictable or possibly intermittent supply of such energy. To understand these challenges, we currently lack sufficient tools to evaluate the impact of different energy harvesting and transfer models - which is further exacerbated due to the high cost of deploying such systems at a large scale. We present a generic, TOSSIM-based simulation framework to model energy harvesting and energy transfer, enabling rapid development of harvesting- and transfer-aware applications, protocols, and system software. uation shows that even an abstract simulation model can provide useful insights, such as frequent power outages and node reboots due to intermittent energy supply. Based on th...