The Energy Department's National Renewable Energy Laboratory, or NREL, along with partners from the Electric Power Research Institute and the University of Colorado collaborated on the comprehensive study. The primary aim was to gain an understanding of how wind power technology can assist the power grid by controlling the 'active power output' being placed onto the system. The rest of the power system's resources have traditionally been adjusted around wind to support a reliable and efficient system. The research that led to this report challenges that concept.
The study, "Active Power Controls from Wind Power: Bridging the Gaps", finds that wind power can support the power system by adjusting its power output to enhance system reliability. Additionally, the report finds that it often could be economically beneficial to provide active power control , and potentially damaging loads on turbines from providing this control is negligible. Active power control helps balance load with generation at various times, avoiding erroneous power flows, involuntary load shedding, machine damage, and the risk of potential blackouts.
"Utilities and independent system operators are all seeking strategies to better integrate wind and other variable generation into their electric systems," siad Erik Ela, NREL analyst. "Few have considered using wind power to support power system reliability."
The study included a number of different power system simulations, control simulations and field tests using turbines at NREL's National Wind Technology Center, or NWTC. The report developed proposals for new ancillary services designs in U.S. wholesale electricity markets, studied how wind power affects system frequency in the western U.S. with and without active power control, and tested the use of active power control at the NWTC to better understand the performance and structural impacts on wind turbines when providing active power control to the electric system.
"Although many of the control strategies have been proven technically feasible and are used in many regions of the world, only a limited number of wind turbines in the United States are currently providing active power control," Ela explained. "The reason is that the stakeholders – system operators, manufacturers, regulators and the plant owners – all have different goals and perspectives. This report covers many different aspects of the topic in order to address the diverse viewpoints throughout the wind industry."
The comprehensive, 154-page report is available online.