Is the Grid blowing in the wind?

Wind 2007 – the good news

2007 was a banner year for wind integration in the United States. There was more wind generation installed in the United States in that year then anywhere else in the world, approximately 5200 MW. The U.S. is now second only to Germany in the number of megawatts generated by electricity. Save natural gas, more wind capacity was introduced in the United States than any other source.

The states with the most wind capacity are:

·                     Texas – 4356 MW

·                     California – 2349 MW

·                     Minnesota – 1,300 MW

·                     Iowa – 1,273 MW

·                     Washington – 1,163 MW

In its “2007 Long-Term Reliability Assessment” report, the North American Electric Reliability Council (NERC) projected a 20% growth in demand over the next 10 years. (See NERC link below.) On February 21, in a keynote address at the National Transmission Forum in Washington, D.C., NERC President and CEO Rick Sergel said we need to think of transmission as a “clean energy superhighway”, an enabler for future development of renewable generation resources.

Wind 2008 -- the not so good news

The Energy Reliability Council of Texas (ERCOT) is the independent system operator that manages the region’s grid with oversight by the Public Utility Commission of Texas (PUCT).  As SGN reported in March 2008 (see Smart Grid News article link below), ERCOT operators had to react promptly on February 26 to balance load through demand response (DR) because of system reliability problems caused by wind intermittency. But systems reliability was not the only issue caught in the headlights by this event.  The Wall Street Journal also spotlighted the economic impact; namely that the unexpected loss of wind generation caused wholesale power prices to soar from $30 per MWH to $105 per MWH in West Texas.

System reliability and pricing challenges

So the February 2008 ERCOT situation puts into harsh relief the system reliability and pricing challenges faced by utilities attempting to integrate wind into their generation portfolio.  These challenges boil down to two primary problems:  (i) operating with wind and (ii) market pricing with wind.

Operational problems include:

·      Output can be counter to load ramps or faster then system ramp.

·      Wind patterns can be unpredictable.

·      There is a need for dispatchable generation capable of matching wind intermittency.

·      Wind has relatively low capacity factor and may be nonexistent at peak times.

·     Wind may create oversupply problems.

NERC is very concerned about maintaining bulk power reliability, regardless of generation. At a recent webinar, NERC discussed its formation of a task force for developing the integration of variable generation. (See NERC link below.) NERC plans to evaluate operational requirements and recommend standards providing a consistent approach for rating variable resources. The task force expects to issue its report in January 2009.

Market problems include:

·   Price and load forecasting is difficult and mistakes costly.

·   Market rules and tariff provisions need to be modified to maximize value of weather driven resources.

The American Wind Energy Association (AWEA) points out that there will need to be well functioning real-time, hour ahead and day ahead energy and price responsive load markets, as well as expanded access to those markets.

The future of wind

The AWEA estimates that U.S. installed wind capacity can reach 30,000 MW in 2010 (compared to 16,218 MW today), generating 105 billion kWh annually. (See AWEA link below.) This is enough electricity to meet the needs of more than 10 million homes, and to displace 100 million metric tons of CO2, or 18% of the utility sector's excess emissions.

Federal and state incentives and mandated renewable standards, along with investor interest generated by recent European wind farm public offerings, will all drive additional wind generation. Whether the grid can keep up is another matter.

NERC “2007 Long-Term Reliability Assessment” report (PDF) 

NERC’s Wind Integration & Transmission Webinar

Smart Grid News article  (March 5, 2008)                                 

AWEA website