Sewer energy mill system

A sewer energy mill system for converting the kinetic energy of wastewater flowing through a sewer line into electrical energy, comprising a modular unit including:

• an energy extracting device mounted to a rotatable shaft and positionable whereby wastewater flowing through the sewer line rotates the shaft of the energy extracting device;
• an alternator for generating electricity, the alternator having a rotatable shaft, the shaft of the alternator operatively connected to the shaft of the energy extracting device in a driving relationship for rotating the shaft of the alternator;
• and
• a drive mechanism for operatively connecting the shaft of the alternator to the shaft of the energy extracting device for rotating the shaft of the alternator;
• said modular unit selectively insertable and retractable within a manhole structure opening to the sewer line.

A method for converting kinetic energy of wastewater flowing through a sewer line into electrical energy comprising the steps of:

• providing an energy extracting device mounted to a rotatable shaft in a manhole chamber opening to the sewer with the energy extracting energy operatively disposed whereby wastewater flowing through the sewer line rotates the shaft of the energy extracting device;
• providing an alternator having a rotatable shaft in operative association with the energy extracting device whereby the shaft of the energy extracting device is connected in driving relationship with the shaft of the alternator for rotating the shaft of the alternator;
• installing an inlet channel having a variable flow area throat within the sewer line upstream with respect to wastewater flow of the energy extracting device;
• selectively varying the flow area of the variable flow area throat in response to at least one of a sensed wastewater head pressure at a location upstream of the energy extracting device and a wastewater flow velocity approaching the energy extracting device.