Experiences in aggregating distributed generation for system benefit

Many data centers, medical complexes, government facilities, factories and other commercial buildings have standby electrical generators. Quiet for most of the year, the generators are only used in the event of a power outage or for periodic testing. Portland General Electric (PGE) offers a program aimed at supplying capacity resources that utilizes these hidden resources to their full potential as a single aggregated generating peaking plant. PGE's "dispatchable standby generation" (DSG) program currently ties together 15 MWs of standby generators to support peak power demand on PGE's system and to ensure reliable service for customers. This power can also help avoid buying wholesale power when prices are skyrocketing or may allow less expensive resources to be utilized while DSG power can be counted as reserve capacity. DSG generator power first supplies power to its designed load at the facility and any excess power flows into the PGE system. To the PGE system grid, this appears as a drop in load and a small increase in supply. Finally, PGE links the GenOnSys application to PGE's system control center's energy management system via a secure fiber connection.