Developers in Oklahoma and other windy states are ramping up construction on wind farms in the wake of a last-minute renewal of a key federal tax credit for a few weeks before the end of 2014.

The American Wind Energy Association said 13,600 megawatts of capacity was under construction across 101 projects in 24 states. Oklahoma is expected to add another 1,440 megawatts from eight projects under construction.

Oklahoma added 150 megawatts of wind capacity in the second quarter, according to the association's latest market report. The addition came from the Osage Wind project in Osage County hooking up to the electric grid. The project, owned by Enel Green Power North America Inc., supplies power to Missouri-based Associated Electric Cooperative Inc.

In the state rankings, Oklahoma remained in fourth place, putting its total wind capacity at 3,932 megawatts. The U.S. had a total of 67,870 megawatts of wind capacity by the end of the second quarter, the association said.