Energy saving is currently one of the most important issues in the development of battery-powered wireless sensor nodes (WSNs). We have developed a non-volatile reconfigurable offloader for flexible and highly efficient processing on WSNs that uses NanoBridges (NBs), which are novel non-volatile and reprogrammable switching elements. Non-volatility is essential for the intermittent operation of WSNs due to the requirement of power-on without loading configuration data. We implemented a data compression algorithm on the offloader that reduces energy consumption during data transmission. Simulation results showed that the energy consumption on the offloader was 1/21 of that on an ultra-low power CPU.