Bio-energy Technology Advances that Promote Wastewater Utility Energy Independence

Energy management concepts that include bio-energy and energy recovery from wastewater
digestion as a source of renewable energy promotes sustainability and is an important first
step towards energy independence for wastewater utilities. Energy independence can be
achieved through energy conservation, creating more efficient systems, and development of
renewable energy including bio-energy production, solar, geothermal and wind power1.
Therefore a movement toward maximizing utilization of biologically derived energy coupled
with other renewable energy sources has recently become of more interest to wastewater
facility management. Energy recovery from innovative and recent technical advances in
digestion and bio-solids provides an opportunity for wastewater utilities to invest in energy
management strategies to optimize the recovery of energy from various digestion processes,
thermal drying and solids reduction and stabilization strategies to reduce the cost of
treatment. This paper proposes a benchmark of 7.0 Kw-h/month/Kg TSS (15.4 Kwh/
month/lb TSS) for maximum electrical production efficiency for biogas fueled facilities.
Those facilities that use biogas as a fuel source and approach the upper end of this energy
efficiency benchmark should be close to neutral electricity consumption.