Southwest Power Pool set a wind-penetration record of 52.1% at 4:30 a.m., Feb. 12, becoming the first regional transmission organization (RTO) in North America to serve more than 50% of its load at a given time with wind energy.

The milestone beats a previous North American RTO record of 49.2% that SPP set April 24, 2016. Wind penetration is a measure of the amount of total load served by wind at a given time.

As recently as the early 2000s, SPP’s generating fleet included less than 400 MW of wind, and for years, wind was reported in the “Other” category in SPP’s fuel mix data. Wind is now the third most-prevalent fuel source in the SPP region. It made up approximately 15% of the organization’s generating capacity in 2016, behind natural gas and coal.

Installed wind-generation capacity increased in 2016 alone by more than 30% — up 4,000 MW from 12 GW to more than 16 GW. SPP’s maximum simultaneous wind generation peak rose from 9,948 MW in 2015 to 12,336 MW in early 2016.

The RTO’s footprint covers almost 550,000 square miles from the Canadian border in Montana and North Dakota in the north to parts of New Mexico, Texas and Louisiana in the south.

SPP has approved the construction of more than $10 billion in high-voltage transmission infrastructure over the last decade, with much of it being built in the Midwest to connect rural, isolated wind farms to population centers hundreds of miles away.