Paying for Themselves, An Evaluation of Turbo Blower Life-Cycle Costs

Many municipalities are identifying ways to reduce energy consumption at their wastewater treatment plants (WWTPs) to reduce operating costs and conserve resources. Aeration is typically the highest energy demand at WWTPs, consuming up to 60 percent of the overall power usage. Therefore, some municipalities have started replacing aging blowers with high -efficiency turbo blowers, resulting in substantial power savings. Two case studies in which turbo blowers were either temporarily or permanently installed at a WWTP are examined in this paper. Data collected during the studies were used to quantify the energy cost savings and calculate payback periods associated with installation of the turbo blowers. In the case studies, installation of the turbo blowers resulted in a 32 to 38 percent energy savings. Calculated payback periods for the total capital cost of the turbo blower installations ranged from 10 to 24 years. Calculated payback periods for the difference in capital cost between installing turbo blowers and installing the alternative blower technology ranged from 5 to 6 years.