Featured News

Milton-Freewater, Oregon: Pioneers in Load Management
August 20, 2011
by Barbara Chadek, Electric Assistant

The City of Milton-Freewater has been a pioneer of load management and low-cost electricity since 1985, when it installed approximately 500 radio energy management units, or REMS in customers' homes. The units can control electric heat, electric water heaters and air conditioning and work together with the City's supervisory control and data acquisition, or SCADA, software to continually monitor system demand as part of an overall Load Management System.

When Milton-Freewater's electrical system reaches its peak demand for power, the Load Management System is activated. When activated, the software sends an FM radio signal to the REMS unit in the customer's home, which controls the various connected systems. These REMS units are one-way communicating units meaning that the signal is sent from SCADA out to the units to shut off, but no return signal is sent back to confirm they've received the signal. So while the City can see customers' demand for power drop as a whole system, it cannot monitor what each unit is doing individually.

As part of the Pacific Northwest Demonstration Project team, Milton-Freewater has started replacing all REMS units with devices called Demand Response Units, or DRUs, which are capable of two-way communication. The City is soliciting for volunteers to activate approximately 800 units total that will curtail more load than before. Using the DRUs, the City can confirm that the DRUs have received a smart signal and have in fact disconnected from the system. In addition, the DRUs allows the City to be able to cycle how long the load is shut off (ex: 15 min. on and 20 min. off) which will assist greatly in making sure that their customers' comfort level is not impacted.

Another load management program actively used by Milton-Freewater is Voltage Reduction. During the time of the utility's system peaks, substation voltage regulators lower the system voltage by 4.5%, which reduces the demand of all resistance loads within the system while still maintaining adequate distribution voltage.

Milton-Freewater is proud to be one of the pioneers of load management and looks forward to working with the Pacific Northwest Smart Grid Demonstration Project in developing and learning about new approaches in load management.

Other News