National Renewable Energy Laboratory (NREL), Technical Report NREL/TP-5D00-60574, Jan. 2014.
http://www.nrel.gov/docs/fy14osti/60574.pdf

"NREL, along with partners from the Electric Power Research Institute and University of Colorado and collaboration from a large international industry stakeholder group, embarked on a comprehensive study to understand the ways in which wind power technology can assist the power system by providing control of its active power output being injected onto the grid. The focus of this report is a mitigation strategy that is not often discussed and is in some ways counterintuitive: the use of wind power to support power system reliability by providing active power control (APC) at fast timescales."