Fortnightly Magazine - May 2008

Windpower's Warning

ERCOT’s February emergency suggests storage capacity is needed to support renewables.

ERCOT in February averted a blackout that could have become a disastrous defining moment for the windpower industry. This near miss can teach utilities and system operators valuable lessons about integrating variable energy sources into the power grid.

Analyzing Asset Failures

Simulation modeling can improve O&M and capital-planning processes.

Electric utilities are faced with the challenge of managing a range of aging distribution assets that are critical to system reliability. They also are threatened with potentially huge costs as they seek to replace these assets over the coming years to maintain reliability. Making intelligent decisions about asset maintenance and replacement requires accurate information about the failure patterns of these assets over time.

What Happened in ERCOT

Voltage sag shows value of accurate wind forecasting.

Variability is a well-known characteristic of windpower, and system operators know they must plan for changes in wind generation over the course of a day. But when those plans fall short, voltage levels can drop quickly, forcing grid operators to dispatch resources to make up the difference—either by shedding load or bringing reserve generation online.

That’s exactly what happened in ERCOT on an evening in February, when a combination of events left the system operator short on power and long on demand (See Figure 1).