Energy need has been increasing worldwide exponentially. At present global energy requirements are mostly dependent on the fossil fuels, which eventually lead to foreseeable depletion of limited fossil energy source. Combustion of fossil fuels also has serious negative effect on the environment due to carbon emission. Concerns about climate change, increased global demand for the finite oil and natural gas reserves and energy security, are intensifying the search for alternatives to fossil fuels. There are several biological processing strategies that produce bioenergy or biochemical while treating industrial and agricultural wastewater, including methanogenic anaerobic digestion, biological hydrogen production, microbial fuel cells The topic revealed the significance of bio electricity derived from the microorganism isolated from the waste water and algal technology will be new source to be utilized in the future. I hope that this book will be helpful to the young scientists of this relavent field and also the students alike and act as a stimulus for further research.