By adjusting power output, a new analysis from the USA Energy Department and its research partners shows that wind farms can improve power grid reliability through active power control. Thus, the wind power producers could enter in the market of frequency regulation services and clean the image of wind power production as unreliable and intermittent, a type of energy that requires fossil fuels back-up units.
According to the study run by US Energy Department’s National Renewable Energy Laboratory (NREL), Electric Power Research Institute and the University of Colorado, wind power can support the power system by adjusting its power output to enhance system reliability. More precisely, the study states that wind farms can be constructed in such manner that their output can be controlled as to provide frequency regulation, a service grid operators rely on to ensure reliable power delivery.
NREL study 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.”
One of the authors of the study, who is also a wind analyst for NREL, observed that wind turbines can perform the frequency regulation that natural gas power plants do by lowering their output thanks to a changing pitch of their blades slightly. That way, wind turbines can make second-by-second curtailments that allow grid operators to keep the power supply and demand balance.
The honest and reasonable conclusion, based on the findings of the study, is that in certain situations, the temptation to sell as much energy as possible when wind is abundant must be resisted. As an alternative, money-making and grid power safety and reliability can be achieved if utilities and independent system operators will use wind power to achieve this reliability. In this way, a strategy to better integrate wind and other variable generation into power systems can be constructed.
Providing frequency regulation services can bring wind farms big money “because the grid values these services so much, [wind farms] can actually earn more money by curtailing and providing services than if they’re providing energy,” the same NREL analyst declared. The economics of wind power generation and delivery makes him justice on this up to a point.
Green Tech Media correctly says that „there are times in the middle of the night when wholesale energy prices are negative because there is excess wind power. At those times, frequency regulation services would be more valuable than providing energy.” The media outlet indicated that some wind turbine producers included the required electronics for active power output control in their products, but the low awareness from wind farm operators stay in the way of more active power management. By comparison with a gas power plant or worse, a coal-based power plant, with big additional capital cost for stand-by and intervention, wind farms can act faster and cheaper for frequency regulation.
The research says that all the benefits the study identified cannot be properly used unless system operators, manufacturers, regulators and the plant owners don’t harmonize their goals, stakes and perspectives. For instance, in USA, only Texas allows wind power to provide frequency regulation, and in Europe only Denmark and Spain entered on this path.
But developments are sure and steady. IBM developed in 2013 a system to gather data from wind turbine sensors to predict the output of wind and solar with a high degree of accuracy, making it easier for grid operators to integrate wind. General Electric, meanwhile, has complemented its wind turbines with analytics and relatively small energy-storage devices in order to create a more consistent power output onto the grid.