Oklahoma Governor Mary Fallin signed a controversial bill into law that rolls back to 1 July the remaining state tax incentive available to the wind industry that legislators had earlier pledged to preserve through 2020.

Developers use the Zero-Emission Facilities Tax Credit to reduce their tax liability during the initial decade a wind farm is in operation. The incentive provides $5/MWh for power generated with unused credits refundable for up to 85% of its face amount.