Recently more and more sensor networks are powered by diverse environmental energy surrounding the deployment field. The charging process of such nodes results in intermittent network topology, through which it is very hard to deliver packets efficiently. CTP is a de facto routing protocol for wireless sensor network applications driven by the TinyOS. It constructs and maintains a routing tree by using the metric of ETX. However, it is still a question about whether CTP well suits the wireless sensor network with energy harvesting. This paper empirically evaluates CTP through a 50-node test bed and provides in-depth analyses of CTP's efficiency and efficacy. The experimental results also provide insights and guidance to facilitate designing new routing protocols for energy-harvesting wireless sensor network applications.