Energy Recovery is the Goal
in Public Works Project
Sorensen Systems developed and installed a renewable energy system in Keene, NH. This system converts excess pipe pressure and flow into clean “green” power. This Water-to-Wire energy recovery project produces 480 VAC (volts alternating current) power from water flow exiting the treatment plant.
Project Manager John Ford explained that the system incorporates 22 kW and 40 kW dual-turbine generators. The system generates electricity. Which it then sends to the power grid. This offsets the plant’s electricity consumption. Officials from the Keene, NH, Public Works Department noted that this marks the first installation of its kind in New Hampshire. Which offers a unique opportunity for gravity-fed water systems utilizing regulator valves.
Remote Control Hydro-Turbine Operation
In addition to two turbine generators, Sorensen Systems designed and constructed control cabinets. These cabinets feature controls and status indicators that allow monitoring of the turbine generators’ operation. The system’s control cabinet is dual-bay. This means the left-hand side housing controls are dedicated to the 22 kW turbine generator, and the right-hand side controls specific are to the 40 kW turbine generator.
The PLC (programmable logic controller) used to control all operating features for both turbine generators. It is an Allen-Bradley Compact Logix platform that communicates with the SCADA (supervisory control and data acquisition) system via EtherNet. A main disconnect circuit breaker is located under the central pillar on the front of the control cabinet. This device can isolate the entire control cabinet from the mains AC line and to shut off power to all circuitry.
Turbine-Generator Control Systems
Each turbine generator has its own touch-screen. These HMI’s monitor all operational parameters for each turbine generator. They also allow for local control the operation of the turbine generators. The monitors can help with diagnosing fault conditions in the turbine generator controls. Each turbine generator has a key-lock switch on the control front panels. These switches have three positions: Local, Remote, and Off. Operators can use the switches to determine the source for the on/off control signals for the turbine generators, or to lock out the turbine generator from operation.
Each turbine generator has its own HMI screen that is used to control its operation and to display status information. These HMI’s default to the main status screen or Turbine System State. This screen displays the status information for its turbine generator. There are two distinct functions: numerical displays for turbine data and pushbuttons to select further display for the generator. The touch-screens on this system are the primary means for a machine operator to monitor and control the operation of the turbines locally. The HMI’s display five screens. They are 1) Turbine Systems State, 2) Intertie Status, 3) Turbine Status, 4) Turbine Maintenance Controls, and 5) Turbine Local Start Controls.
480 VAC power grids provide power to the controls. However, once the turbines are on-line and generating power, the power source for this cabinet are the turbine-generators. The front panel controls for each turbine generator are similar. Each turbine generator has a number of devices mounted on its front panel. The devices are used for independent monitoring and operation of each turbine generator.
Water-to-wire solutions are a single source project. This ensures that all components fit together. Sorensen Systems ensures that all deliverables are met. For an easy to install solution, consider a water-to-wire project through Sorensen Systems.