In ambient monitoring applications, the sensing field may be so far away from the data center that causes the direct relay routes between the sensor network and the data center impossible. Typically, in such isolated sensor network, data is stored in a distributed manner and collected by data mule. To improve the efficiency, sensed data is normally stored near the area where the mule will pass by with respect to storage limitation. However, previous researches didn’t consider the energy constraint and energy harvesting capability of nodes. The purpose of this paper is to design a solution for fair data storage under space and energy limitation only based on local information. We propose a heuristic Distributed Energy-aware Data Conservation method (DEDC), which considers following two issues: i) where to store data with respect to energy and space storage, ii) how to prioritize the transmission of important data. Simulation has shown that the method is effective, energy efficient and robustness.