This paper shows an Incremental Redundancy Hybrid automatic repeat request (HARQ) scheme, based on rateless coding, for wireless sensor network (WSN) protocols. The proposed approach proved to be effective under energy consumption constraints, making it suitable for possible applications to WSNs. Moreover, the use of a rateless coding scheme increases the average throughput by limiting the length of retransmitted packets. Performance are evaluated through simulations in terms of average goodput and average energy consumption, comparing the presented solution with the traditional ARQ scheme employed in the IEEE 802.15.4 standard for WSNs. Results have been obtained using a novel network simulation model for rateless code transmissions based on information theoretic measures.