Structural health monitoring consists of an integrated paradigm of sensing, data interrogation, and statistical modeling that results in a strategy to assess the performance of a structure. Sensor networks play a central role in this paradigm, as such networks typically perform much of the actuation, data acquisition, information management, and even local computing necessary to enable the overall implementation of the strategy, increasingly in a wireless mode. In many applications power provision can become a limiting factor, as the conventional strategy for wireless networks is a battery. However, batteries require replacement, as their useful shelf lives often do not exceed the intended service of their host structures. Energy harvesting has emerged as a class of potential network powering solutions whereby one form of energy available on the structure is harvested and converted to useful electrical energy. The objective of this work is to investigate the harvesting of energy from galvanic corrosion that typically occurs naturally in many structures. Specifically, this study considers corrosion between magnesium and graphite rods embedded in a concrete structure immersed in seawater. The energy was evaluated by connecting a .1F capacitor and measuring the voltage charge over finite time intervals during the corrosion process. A carbon fiber admixture was introduced to the concrete host to improve electrical conductivity, and the power increase was calculated from voltage measurements. The investigation concludes that the voltage levels achieved may be naturally integrated with a booster circuit to provide CMOS voltage levels suitable for sensor network powering in some applications.