This chapter illustrates how microbially produced electricity can be harnessed directly to power applications and/or be used as a novel method of sensing. For applications requiring higher power, the continuous power produced will not be sufficient and so energy harvesting electronics can be employed. Energy harvesting technology has quickly advanced to become very affordable and ideal for use with MFCs, and examples of how the two technologies can be integrated for practical implementation are reported. Finally, field trials are an important step for advancing the technology to the next stage and some examples of both successful and unsuccessful field trials will be discussed in the final section.