Central Generation Station for Fargo
Wastewater Treatment Facility
The Central Generation Station (CGS) is a 3,480-square-foot building at the northwest corner of the Wastewater Treatment Plant that houses four 1-Megawatt natural gas generators. Inside the CGS – the paralleling switchgear acts like a traffic cop, directing the flow of utility and generator-produced power to the rest of the plant.
Of course, if the plant loses utility power due to a storm or other reasons, all the generators can come online to run the plant. But even more impressive, plant operators can use the Supervisory Control and Data Acquisition (SCADA) system to set on-peak hours and load shed setpoints that the switchgear will monitor. During times when the facility power usage is highest and/or the electric rate is most expensive, the paralleling switchgear can call any number of generators online to “peak shave” or subsidize more expensive electricity with lower-cost, natural gas-generated power.
To accomplish the task, the switchgear incorporates Woodward easYgen™ genset controllers that monitor the generators; wait until their output matches the voltage (12.47kV), frequency (60Hz), and phase angle of the incoming utility power; and tell the breakers to close and bring the generator power online in synchrony with the facility’s power network.
In addition to peak shaving, the City of Fargo is realizing savings on its electric bill just by consolidating what was once multiple electrical services into a single service. As with most products, better deals come when buying in bulk, and electricity is no different. One large utility feeder means fewer fees, penalties, and extra charges; and the simplified billing and elimination of metering and generator equipment around the property mean fewer headaches for plant operators and city personnel.
It requires more energy to start a pump than it does to keep it running once it’s up to speed. So as Apex and the City of Fargo complete their Phase IIB upgrades to the wastewater treatment facility and add more equipment in the coming years, more capability will also be added to the SCADA system to prioritize pumps and equipment and the order in which they come back online during a power outage. Turning components back on a few at a time rather than all at once will alleviate the initial load on the generators and switchgear and extend their lifecycle.
Additional power usage metering and customized power monitoring have also been built into the SCADA, giving operators and managers more knowledge about how and when power is being used. This will enable them to see how operational changes affect power usage and ultimately the costs of operating the facility.
City of Fargo