US grid operator SPP cracks 50% wind for the first time

The Southwest Power Pool (SPP) has become the first of North America’s 10 grid operators to source more than half of its power from wind at a given moment, setting a continental wind-penetration record of 52.1% on the morning of 12 February.

The Little Rock, Arkansas-based SPP oversees the bulk electric grid and wholesale power market across a 14-state, 550,000-square mile (885,000 sq km) area in the central US, a region that has seen huge growth in its operating wind capacity over the past few years.

At the beginning of the century SPP had only a few hundred megawatts of wind on-line in its service area, and wind’s contribution to the electricity mix was so miniscule that it was classified as “Other” in SPP’s fuel-data statistics.

Today the region covered by SPP – stretching from the Canadian border in North Dakota down to parts of Texas – has more than 16GW of spinning wind turbines, and wind contributed 15% of the total power on its system last year, behind natural gas and coal.

“Ten years ago we thought hitting even a 25% wind-penetration level would be extremely challenging, and any more than that would pose serious threats to reliability,” says Bruce Rew, SPP’s vice president of operations.

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“Now we have the ability to manage greater than 50% wind penetration, and it’s not even our ceiling,” Rew says. “We continue to study even higher levels of renewable, variable generation as part of our plans to maintain a reliable and economic grid of the future.”

SPP’s ability to absorb and balance large amounts of variable wind power stems in part from the vastness of its geographic footprint.

SPP covers the entirety of wind-heavy states like Kansas and Oklahoma, as well as portions of other states like Texas and New Mexico. Much of Texas’ wind capacity is overseen by the Electric Reliability Council of Texas (ERCOT), a different grid operator.  

“We’re able to manage wind generation more effectively than other, smaller systems can because we’ve got a huge pool of resources to draw from,” Rew explains. “Even if the wind stops blowing in the upper Great Plains, we can deploy resources waiting in the Midwest and Southwest to make up any sudden deficits.”

SPP says it has approved the construction of more than $10bn in high-voltage transmission infrastructure over the past decade, much of it in the Midwest to connect rural, isolated wind farms to distant population centres.