  This work considers a system with two energy harvesting (EH) nodes
transmitting to a common destination over a random access channel. The amount
of harvested energy is assumed to be random and independent over time, but
correlated among the nodes possibly with respect to their relative position. A
threshold-based transmission policy is developed for the maximization of the
expected aggregate network throughput. Assuming that there is no a priori
channel state or EH information available to the nodes, the aggregate network
throughput is obtained. The optimal thresholds are determined for two
practically important special cases: i) at any time only one of the sensors
harvests energy due to, for example, physical separation of the nodes; ii) the
nodes are spatially close, and at any time, either both nodes or none of them
harvests energy.
