Electric Co-op Today

Reliably integrating high levels of variable resources such as wind into the bulk power system will demand significant changes to traditional methods of system planning and operation, the grid reliability watchdog asserted.

The challenge stems from key characteristics of variable resources, according to the North American Electric Reliability Corp. Their fuel supply and output cannot be controlled or stored, NERC noted, and often are located far from electricity demand.

Timing is another challenge, as the peak availability of wind power, the most abundant variable resource, often occurs during periods of relatively low electricity demand.

Additionally, the grid watchdog said, variable resources’ output is characterized by steep “ramps,” as opposed to the controlled, gradual up or down movements generally associated with electricity demand and the output of generation sources such as fossil fuels.

These issues must be addressed, NERC noted in a report, “Accommodating High Levels of Variable Generation,” released April 16.

NERC pointed out that its 2008 Long-Term Reliability Assessment projected that more than 145,000 mega­watts of new variable resources would be added in the next decade.

Tags: Electric Grid, North American Electric Reliability Corporation, Transmission and Distribution