Aeration System Energy Cost Savings through Improved Efficiency and Control

Aeration systems for biological treatment processes typically account for 40 to 60 percent of the total energy consumed at most WWTPs. There are a number of improvements that can significantly improve the efficiency and reduce operating costs of the aeration systems, including installation of higher efficiency blowers, higher efficiency diffusers and automatic control systems. Typically, these improvements have a higher capital cost and require an attractive payback period. This paper will describe key issues and strategies to maximize energy savings when faced with facility expansion or with rehabilitation of existing facilities. Recent work has shown that in addition to the traditional steps in developing an optimized energy efficient blower system, engineers are now considering the mix and matching of blower types (hybrid system) to optimize the payback for improvements. Three case studies are presented to demonstrate the approach in maximizing the most cost– effective improvement in energy efficiency. Examples include the use of different blowers in a single system (hybrid system) to maximize use of existing units (reduced capital) and development of an operating strategy to use the most efficient type of blower under the service condition.